TCi EZ-TCU User manual

EZ-TCU™ Transmission Control Unit
Thank you for choosing TCI® products; we are proud to be your manufacturer of choice. Please read
this instruction sheet carefully before beginning installation, and also take a moment to review the
included limited warranty information.
INSTALLATION
System Components Overview
The EZ-TCU™ system is made up of several main components. A TCU (Transmission Control Unit),
a wiring harness, a handheld user interface, and an RPM module. Please read through all of the
installation notes before beginning the installation.
TCU
TCU Installation Notes:
•The TCU is water tight when connected to the wiring harness. It can be mounted in the engine
compartment or in the vehicle’s interior. It is good practice to mount the TCU with the
connector facing down. This way, there is less chance of moisture getting into the TCU if it
needs to be disconnected in wet conditions.
•The TCU should not be mounted close to other electrically “noisy” components. In particular,
keep good spacing (try for 2 feet minimum) from ignition components (ignition boxes, coils,
distributors, etc.)
•If mounting in the engine compartment, selecting a location towards the rear will make it easier
to route the communications cable to the interior to allow the handheld to be monitored while
driving. Optional, longer communications cables are available if needed.
•There is an LED on the front face of the TCU – the side with the logo. It will flash if the on-
board diagnostics detects a problem (the LED is lit solid when the TCU is powered up and
working normally). To take advantage of this feature, the TCU will need to be mounted so that
the front face of the TCU is visible. The handheld will also indicate if any faults have been
detected.

Wiring Harness
Wiring Harness Installation Notes:
•The wiring harness should be kept away from ignition components (ignition boxes, coils,
distributors, etc.) as much as possible. Do not bundle the wiring harness together with other
“noisy” wiring in the vehicle.
•As with any wiring, it is good practice to avoid routing the wiring harness around sharp edges
or near high temperature components such as headers.
The wiring harness consists of the following connections:
BATTERY POS (loose wire)
BATTERY NEG (loose wire)
These must be connected DIRECTLY to the positive (red wire) and negative (black wire)
posts of the battery. These must be run independently to the battery. Do NOT splice other
power or ground wires into these wires. Failure to follow these requirements invites problems
with electrical noise. These kinds of problems are difficult to diagnose. The wires may be
extended if needed using automotive grade 16 gauge (or larger) wire.
12V SWITCHED (loose wire)
Connect this wire to a switched ignition source that is hot with the key in the On/Run and
Crank positions. Do NOT connect to the positive side of an ignition coil. Strange problems can
sometimes arise when tapping into existing switched ignition sources. When in doubt, run this
wire through its own switch and then directly to the positive post of the battery.
TRANS
This connects to the round connector on the passenger side of a 4L60E transmission. Or on the
driver side of a 4L80E or TCI® 6x Six-Speed transmission.
NOTE: Pre-1993 4L80E’s will need an updated internal wiring harness. TCI® PN 276610, GM
PN 24200161 or equivalent.

4L60E 4L80E / TCI® 6x Six-Speed
OUTPUT SHAFT SPEED
This connects to a speed sensor at the rear of the transmission. In the case of the 4L80E and
TCI® 6x Six-Speed transmissions, use the rear most sensor.
THROTTLE / TPS SIGNAL
The THROTTLE connector can be plugged into an early style GM TPS sensor. Wiring
adapters are available from FAST™ to accommodate a later style GM TPS (round, 3 pin
connector). The harness can also be modified for use with any 0-5V TPS.
Original
Pin Location Color Function
A Black/Pink Ground
B White/Red TPS signal
C Red/White 5V
The loose TPS SIGNAL wire is provided to facilitate sharing the TPS signal between two
systems (TCU and a fuel injection system, for example) if needed. It splits off from the
THROTTLE connector’s signal wire inside the harness.
Remote mount TPS kits are available from TCI® to provide a TPS signal for carbureted
applications.
TACH IN / RPM MODULE
The wire with the female terminal goes to the tach output from an ignition box or other RPM
signal source. Or to the EZ-TCU™ RPM Module depending on the application. See RPM
Module notes. Do NOT connect this directly to the ignition coil.
A second wire is provided to facilitate sharing the tach signal between two systems (TCU and a
fuel injection system, for example) if needed. The terminal on the second wire is the opposite
gender. So something that would normally connect to an ignition box tach output or the EZ-
TCU™ RPM Module can instead be plugged into this second wire in the TCU harness for a
splice-free hook up.
MANUAL SHIFT
This connector contains the wires needed to enable and use manual bump up/bump down
shifting. Buttons can be mounted where ever they are convenient in the vehicle – on the

steering wheel, on the shift lever, etc. TCI® offers shifters and accessories that can be used for
this purpose.
Pin Color Function Notes
A Red Bump Down Use momentary switch to ground to request a downshift.
B Yellow Bump Up Use momentary switch to ground to request an upshift.
C Blue Auto/Manual Use a toggle switch to ground to enable Manual Shifting.
D Black Ground Can be used as the ground source for switches.
SPEEDOMETER OUTPUT (loose wire)
This wire puts out a 12V square wave to drive an electronic speedometer. The number of pulses
per mile is selected in the handheld.
ECONOMY / PERFORMANCE (loose wire)
When switched to ground through a toggle switch, this TCU input can be used to select a more
performance oriented shift strategy. Line pressure and shift points will be altered according to
settings entered in the handheld.
TCC APPLY (loose wire)
When switched to ground, (and when some very basic requirements are met) this TCU input
forces the torque converter clutch to lock up. Otherwise, the TCC will lock and unlock
automatically based on user configurable settings.
FLASH ENABLE (loose wire)
This wire is only used in the rare case that new firmware needs to be loaded into the TCU.
This wire would be grounded as the TCU is keyed on. Be sure that this wire is not accidentally
grounded in normal operation. If the TCU accidentally starts up in Flash Mode (LED flashing
steady on/off pattern – a slower pattern than the rapid flashing that indicates an error code has
been set), the transmission will not function properly. If that occurs, make sure the FLASH
ENABLE wire is not grounded, then key off, wait about 10 seconds and key back on.
HANDHELD
This connects to the communications cable the links the main wiring harness to the handheld
user interface.
SPEEDOMETER CONTROL UNIT
This connects to an optional TCI® Speedometer Control Unit (SCU). An SCU uses an electric
motor to spin a special speedometer cable to drive a mechanical speedometer.

RPM Module
There are two basic options for supplying the EZ-TCU™ with an RPM input.
1. Clean, processed Tach signal from engine electronics
Electronics involved in running the engine – fuel injection, ignition, etc. – will need to know
engine RPM. So there may be an existing tach signal wire that can be tapped into. The EZ-
TCU™ requires a square wave type tach signal that pulses once per cylinder firing. Ignition
systems – such as aftermarket capacitive discharge (CD) ignition boxes – often have dedicated
“Tach” outputs that are a perfect RPM signal source for the TCU.
If using a clean, processed Tach signal, the TACH IN / RPM MODULE wire in the EZ-TCU™
wiring harness is connected directly to that source - the “Tach” output from an ignition box,
etc. The RPM Module included with the kit is not used in this case. And no part of the EZ-
TCU™ system is connected to the coil.
2. Inductive coil
Another RPM signal source is the negative side of the ignition coil in a traditional dwell
controlled inductive ignition system. One in which the coil is fed power on one side and is
charged by grounding the other side - either by “points” or some form of electronic module.
An HEI is one example of this type of ignition system.
To use this RPM signal option, the RPM Module is required. The RPM Module connects to
the negative side of the coil and outputs a “Tach” signal to the TCU. The RPM Module is
connected as follows:
Wire color Connection
Black Engine block
Black Engine block
White Negative side of coil
Yellow TACH IN / RPM MODULE wire in EZ-TCU™ wiring harness
The RPM Module is provided to allow this convenient installation option. But keep in mind
that it has limitations. The negative side of an ignition coil is one of the noisiest points on the
engine. In most applications, the RPM Module will be able to deal with this and feed a clean
RPM signal to the TCU. But the old saying – garbage in, garbage out - applies here. If the

inductive ignition system is just too noisy or inconsistent, a different RPM signal source will be
needed. A poor RPM signal can cause the RPM display on the Live Data screen to appear
erratic. It can also lead to inconsistent shift points under heavy load.
RPM Module Installation Notes:
•HEI distributors (and possibly others) have a terminal labeled “TACH”. However, that is not a
clean, processed tach signal like an aftermarket ignition box would supply. Instead, it is simply
another terminal connected to the negative side of the coil. Do NOT connect the TACH IN / RPM
MODULE wire in the EZ-TCU™ wiring harness directly to that terminal. The TCU will be
damaged. In a case like that, the RPM Module is required since what you are really doing is
connecting to the negative side of a dwell controlled coil.
•Do NOT bypass the RPM Module and connect the TACH IN / RPM MODULE wire in the EZ-
TCU™ wiring harness directly to the negative side of the coil. It may actually work that way for a
time. But the TCU will be damaged and system performance will degrade.
•Do NOT connect anything from the EZ-TCU™ system to the coil – RPM Module or TACH IN /
RPM MODULE wire – when using an aftermarket ignition box.
•Use resistor type spark plugs. Non-resistor plugs are very noisy and interfere with electronics –
including the EZ-TCU™ system.
•Do NOT use solid core spark plug wires. These are also very noisy.
Speedometer Control Unit (SCU) (Not included in EZ-TCU™ kit)
An optional TCI® SCU uses an electric motor to spin a special speedometer cable to drive a
mechanical speedometer. The SCU wiring mates directly to the EZ-TCU™ wiring harness.
To configure the SCU for use with the EZ-TCU™, remove the SCU’s lid to access a row of DIP
switches. Set switches 4, 5 and 8 to the “ON” position. All others should be “OFF”. Once the
switches are set, the lid can be replaced. In the Setup Wizard or in the Advanced Options menu, set
the SPEEDO PPM to “4000PPM OR SCU”.
In other applications, the SCU needs the DIP switches to be set according to a formula based on
various drive train information. That calculation is not required for use with the EZ-TCU™. Once the

switches are set as described above, the EZ-TCU™ handles the rest. It sends a calibrated speed signal
to the SCU.
Installation Sequence
This is a general outline of the installation process. Read all of the component specific installation
notes for more detail before beginning the installation.
1. Connect the TRANS and OUTPUT SHAFT SPEED connectors from the wiring harness to the
transmission. Route the rest of the harness into the engine compartment.
2. Determine the appropriate method for getting an RPM signal into the TCU. Install RPM
Module if needed. Connect the wiring harness to the RPM signal source.
3. Connect the wiring harness to a TPS signal source.
4. If a mechanical speedometer will be used, install the optional TCI® SCU and connect the
wiring harness to it.
5. Find a suitable location and mount the TCU. Make sure the wiring harness will reach the
mounting location.
6. Connect the BATTERY POS and BATTERY NEG wires DIRECTLY to the battery. These
must be run independently to the battery. Do NOT splice other power or ground wires into
these wires. Extend the wires if necessary to reach the battery. Use automotive grade 16
gauge (or larger) wire.
7. Connect the 12V SWITCHED wire to a switched ignition source (hot in On/Run and Crank).
Do NOT connect to the positive side of an ignition coil.
8. If Manual Shifting will be used, route the MANUAL SHIFTING connector into the cockpit and
wire in an enable switch and a pair of buttons for upshift and downshift.
9. To use the Forced TCC Lockup feature, route the TCC APPLY wire into the cockpit and
connect it to a switch or button.
10. To access Performance Mode, route the ECONOMY/PERFORMANCE wire into the cockpit
and connect it to a switch.
11. If an electronic speedometer will be used, route the SPEEDOMETER OUTPUT wire into the
cockpit and connect it to the speedometer.
12. Connect the wiring harness to the TCU.
Setup
1. Switch on the ignition.
2. Connect the handheld to the main wiring harness using the communications cable. And to
power by connecting the power cable to the handheld and to a cigarette lighter plug. For
convenience, the handheld power source should be hot in On/Run and Crank. If it loses power
while cranking, there will be a short wait before the handheld can be used as it powers back up.
3. Select SETUP WIZARD in the handheld. It will walk you through the setup procedure.
HANDHELD
The EZ-TCU™ handheld serves as the user interface with the EZ-TCU™ system. It has a straight
forward menu system that offers advanced features without requiring a laptop or any computer skills.

Its first task is to take you through the Setup Wizard. It also serves as a scan tool by displaying live
data and diagnostics information. Beyond basic setup, you can also adjust other settings to suit your
preferences.
Handheld Notes:
•The handheld has two cables that must be connected. A communications cable that links the
handheld to the HANDHELD connector on the main wiring harness. And a power cable that goes
to a cigarette lighter receptacle. For convenience, the handheld power source should be hot in
On/Run and Crank. If it loses power while cranking, there will be a short wait before the handheld
can be used as it powers back up.
•To turn off the handheld, disconnect the power cable either at the handheld itself or from the
cigarette lighter receptacle. Reconnect the power cable to restart the handheld.
•If the handheld displays a “COMM ERROR” message, make sure the handheld’s communication
cable is connected and that the TCU is powered on. Then press the RESET button on the
handheld.
•If you will be monitoring live data or making adjustments while driving, be safe and bring a friend
along to operate the handheld while you drive.
Live Data
The Live Data feature allows you to monitor various engine and transmission parameters in real time.
There are two screens that can be selected using the UP and DOWN arrows. To return to the main
menu, press the POWER/MENU button.

In addition to live data readings, the Live Data screens also feature several Status Indicators. They
show when certain conditions are met. In this picture, the TC indicator is “off”. The PM and MM
indicators are “on”. These indicators can serve as a troubleshooting tool by offering a way to verify
that the various switched inputs are wired and functioning properly.
•DASH 1
RPM Engine speed.
MPH Vehicle speed.
GEAR Current gear.
Status Indicator Meaning
TC Torque Converter Clutch. This indicates that the torque converter clutch
is locked. It is normally controlled automatically by the TCU but can
also be forced to lock by grounding the TCC APPLY wire.
PM Performance Mode. This indicates that the ECONOMY /
PERFORMANCE wire has been grounded to select the more aggressive
Performance Mode. When this indicator is off, the TCU operates in
normal Economy Mode.
MM Manual Mode. This indicates that manual bump up / bump down
shifting has been enabled by grounding the Auto/Manual wire in the
MANUAL SHIFT connector. The TCU will hold the current gear until
told to shift, unless the vehicle comes to a stop. In that case, it will
downshift into 1st gear.

•DASH 2
TOT(F) Transmission Oil Temperature.
BAT(V) Battery voltage.
TPS% Throttle Position Sensor. It’s range is from 0 (resting idle position) to 100 (full
open position). The Setup Wizard takes care of calibrating this sensor. It can
easily be verified using this display. If you ever notice the TPS reading is not 0
at idle, it should be re-calibrated by selecting TPS CALIBRATE in the
Advanced Options section of the handheld.
SGR Selected Gear. This shows the position of the shift lever.
PN Park/Neutral
R Reverse
OD4
th lever detent / Overdrive
L33
rd lever detent / Drive
L22
nd lever detent / 2nd
L11
st lever detent / 1st
Status Indicator Meaning
BU Bump Up. This indicates that an upshift is being requested by grounding
the Bump Up wire in the MANUAL SHIFT connector. Manual Shifting
must be enabled for the Bump Up input to be recognized by the TCU and
for this indicator to work.
BD Bump Down. This indicates that a downshift is being requested by
grounding the Bump Down wire in the MANUAL SHIFT connector.
Manual Shifting must be enabled for the Bump Down input to be
recognized by the TCU and for this indicator to work.
SE System Error. This indicates that an error code has been set. It acts like
a Check Engine Light. Select ERROR CODES from the main menu to
check and clear error codes.

Setup Wizard
The EZ-TCU™ Setup Wizard will walk you through the initial TCU setup. Once you select SETUP
WIZARD from the main menu, you will be asked...
•START A NEW TUNE? YES will let you continue the Setup Wizard. It will also
reset most settings in the Advanced Options menu. NO will take you back to the main
menu.
•TRANSMISSION MODEL. Select the transmission type.
•NUMBER OF CYLINDERS. Enter the number of cylinders your engine has.
•TIRE DIAMETER. If you know the rear wheel tire diameter, select ENTER
DIAMETER and enter the value when prompted. Or select USE TIRE SIZE to use
the tire size calculator. It will prompt you to enter the tire section width, aspect ratio
and wheel size that is molded into the sidewall of the tire. The tire diameter will be
calculated and displayed for you to review before continuing.
•SPEEDO OUTPUT. Different speedometers require different numbers of pulses per
mile (PPM). Select the appropriate PPM setting.
If an optional TCI® Speedometer Control Unit (SCU) will be used to drive a
mechanical speedometer, select “4000PPM OR SCU”.
If you won’t be using the EZ-TCU™’s speedometer output, it doesn’t matter what
setting is selected.
If you will be using the EZ-TCU™’s speedometer output but you don’t know what
PPM your speedometer requires, select the “4000PPM OR SCU” option. Later while
driving, this setting can be adjusted with the SPEEDO PPM setting in the Advanced
Options menu.
Some aftermarket speedometers are programmable. For those speedometers, this
setting may not be critical.
•REAR AXLE GEAR RATIO. Enter the gear ratio. This is an important setting. If
you aren’t sure of the exact ratio, enter your best guess for now. Later, you should use
the ADJUST SPEEDO setting in the Advanced Options menu to dial in the TCU’s
speed reading.
•MAX SHIFT RPM. Enter the highest RPM you want your engine to reach during
wide open throttle shifting.
•TPS CALIBRATION SCREENS. The throttle position sensor (TPS) sends a voltage
to the TCU that varies with throttle movement. The TCU needs to know what voltage
corresponds to closed and full throttle. You will be asked to leave the throttle at the idle

/ closed position. Once that value is captured, you’ll be asked to hold the throttle wide
open. The Setup Wizard will tell you how long to hold the throttle open while it
captures that value.
(NOTE: The full throttle procedure is meant to be performed with the engine NOT
running!)
That’s it! The TCU is configured and almost ready to go. The only remaining step is to power
cycle the TCU - key-off, wait 10 seconds, and turn it back on.
Advanced Options
The Advanced Options menu allows you make adjustments beyond the basic settings configured by the
Setup Wizard.
•SPEEDO PPM. Different speedometers require different numbers of pulses per mile
(PPM). If the wrong PPM setting is used, the speedometer readings will be off by a
large margin. The speedometer would read quarter speed, half speed, double speed, etc.
- something pretty obvious. If you don’t know what input your speedometer is
expecting, try other PPM settings until the speedometer displays a reasonable speed.
Some aftermarket speedometers are programmable. For those speedometers, this
setting may not be critical.
•ADJUST SPEEDO. This setting can be used to fine tune the TCU’s speed reading. It
compensates for errors in the entered tire size and rear axle gear ratio.
(NOTE: If an external speedometer – as opposed to the MPH display on the EZ-TCU™
handheld - is grossly mis-calibrated, refer to the SPEEDO PPM setting.)
While the vehicle is being driven, the screen will display the TCU’s current speed
reading. Using the arrow keys, the speed reading can be adjusted up or down. Once
satisfied that the displayed speed is accurate, use the DONE button to lock in the
adjustment.

Since the point of this adjustment is to verify the speed as reported by the TCU, you
will need an independent speed reference for comparison. For example, you could…
- pace yourself against another car being driven at a known speed
- use a GPS unit that displays ground speed
- drive the car on a chassis dyno
•TPS CALIBRATE. The throttle position sensor is calibrated in the Setup Wizard.
This lets you repeat that process by itself. Just like in the Setup Wizard, you will be
asked to leave the throttle at the idle / closed position. Once that value is captured,
you’ll be asked to hold the throttle wide open.
(NOTE: The full throttle procedure is meant to be performed with the engine NOT
running!)
•TIRE SIZE. Rear wheel tire diameter can be adjusted or re-calculated here.
•DIFF GEAR. Rear axle gear ratio can be adjusted here.
•MORE. This brings up another page of Advanced Options.
•MAX SHIFT RPM. The highest RPM you want your engine to reach during wide
open throttle shifting can be adjusted here.
•LOWSPEED SHIFT. This setting is used to adjust the vehicle speeds at which the
transmission shifts under very light load, i.e., when the TPS reading is small. A higher
number means the transmission will shift at higher speeds.
NOTE: The handheld uses the setting entered here to perform calculations related to
shift speeds. The results are what actually get written to the TCU. Not this setting itself.
So anytime you access this setting, it will display the same default value to start. This is
not an indication of a problem. The TCU does retain the shift speed information.

•SHIFT AGGRESS. This setting adjusts how aggressive the overall shift strategy is. A
higher number means that the transmission will hold gears longer and be quicker to
downshift. This setting has a big impact on the overall demeanor of the transmission.
•SHIFT FIRMNESS. This setting adjusts the base transmission line pressure. A higher
number means higher pressure which is felt as firmer shifts. Higher pressure also tends
to allow less slip as the gears engage. Line pressure automatically increases with
increasing throttle and will always be maxed out during full throttle operation. So line
pressure does not need to be set uncomfortably high in normal part throttle driving in
order to get full pressure shifts under heavy load.
Keep in mind that the parts and techniques used in assembling a transmission can have
a large effect on line pressure and shift feel. Adjusting this setting will cause the TCU
to call for more or less pressure. But it is possible for the mechanical/hydraulic
components of the transmission to overpower the control the electronics can have on
line pressure and shift feel.
•6X OVERLAP. This setting is only used with a TCI® 6x Six-Speed transmission. It
affects shift characteristics when shifting between certain gears. Consult with TCI®
tech support before attempting to alter these settings.
•MORE. This brings up another page of Advanced Options.
•MIN TCC LOCK. This setting is the minimum vehicle speed required for the TCU to
lock the torque converter clutch. Locking the TCC while cruising is good for fuel
economy. It also allows the transmission fluid to cool. However, TCC lockup can be
completely disabled if desired by entering an unobtainable speed in this setting. The
vehicle would then always be below the minimum speed for TCC lockup.
•MAX TCC TPS. This setting is the maximum throttle opening allowed before the
torque converter clutch is unlocked. When the TCC locks up, it can feel similar to

shifting into a higher gear. RPM’s typically drop and the engine has to work harder to
accelerate the vehicle. If this setting is too low, TCC will unlock too easily. This can
be an annoyance as it locks and unlocks too often in the course of normal cruising. If
this setting is too high, the vehicle may feel unresponsive during medium to high speed
cruising. As more throttle is applied, the engine may feel like it is struggling until the
TCC finally unlocks and allows the engine to more easily accelerate the vehicle. The
proper setting is subjective. And also dependant on the characteristics of the vehicle
and its powertrain – vehicle weight, engine torque, etc. Some experimentation will
likely be required to find the preferred value for this setting.
•PERF AGGRESS. This setting determines how much more aggressive the shift
strategy becomes when in Performance Mode. A higher number means that the
transmission will hold gears longer and be quicker to downshift. This adjustment is
applied on top of whatever adjustment is already in place through the SHIFT
AGGRESS setting.
•PERF FIRMNESS. This setting determines how much shifts are firmed up when in
Performance Mode. A higher number means firmer shifts. This adjustment is applied
on top of whatever adjustment is already in place through the SHIFT FIRMNESS
setting.
•DONE. This will take you back to the main menu.
Error Codes
The EZ-TCU™ system features a diagnostics feature. The TCU constantly monitors various inputs for
any deviations from normal operation. If any is detected, the LED on the front face of the TCU flashes
rapidly as a warning that there is a problem (the LED is lit solid when the TCU is powered on and
working normally or it will flash a slower on/off pattern if the TCU started up in Flash Mode). Also,
the SE Status Indicator displayed on the Live Data screen acts like a Check Engine Light. It will signal
if an error code has been set. The handheld can be used to read any error codes that have been set.
Once an error code is set, it is saved in the TCU until the TCU is reset by keying-off and allowing the
TCU to complete is shutdown procedure (takes approximately 5-10 seconds). Or error codes can be
cleared with the handheld at any time.
The picture on the left is showing error codes. After clearing them, the picture on the right shows what
the EZTCU Codes screen normally looks like.

The following error codes are possible:
Fault Monitors
TOT Transmission oil temperature sensor open or short. The sensor is inside
the transmission.
OVER TEMP Transmission oil temperature has gone over 262°F.
TPS Throttle position sensor open or short.
BATT Battery voltage below 7V or above 19V for 10 seconds.
PSWM Invalid pattern from pressure switch manifold (internal transmission
sensor that tells TCU what gear is selected.)
If the TCU is completely disabled – power is lost, harness is cut, etc. – the transmission can still be
driven with limited functionality. Line pressure will be maxed out. Reverse will work. The
transmission will default to 3rd gear with the shift lever in Overdrive or L3/Drive. 2nd gear can be
selected by moving the shift lever into the L2 position.
EZ-TCU™ SYSTEM FEATURES AND OPERATION
Performance Mode
When Performance Mode is enabled, the TCU will use a more aggressive shift strategy (transmission
will hold gears longer and be quicker to downshift) and higher line pressure for firmer shifts. The
degree to which both are affected by enabling Performance Mode can be adjusted independently
through the Advanced Options in the handheld. This allows Performance Mode to be adjusted to suit
the driver’s preferences.
Manual Shifting (Bump Up / Bump Down)
By enabling Manual Shifting, the transmission can be controlled with two buttons – one for upshift,
one for downshift. The buttons can be mounted where ever they are convenient in the vehicle – on the
steering wheel, on the shift lever, etc. TCI® offers shifters and accessories that can be used for this
purpose.
In this mode, the TCU will hold the current gear until told to shift, unless the vehicle comes to a stop.
In that case, it will downshift into 1st gear to ensure easy acceleration away from the stop. A side
effect of this feature is that the rear wheels must be turning before the TCU will accept an upshift
request.
Because the TCU will not upshift on its own when Manual Shifting is enabled, care should be taken to
avoid over revving the engine. A rev limiter in a fuel injection or ignition system can act as a safety
net to protect the engine in case the driver waits too long to upshift.

Depending on vehicle speed, the TCU may ignore downshift requests. This is done to prevent over
revving the engine and/or destabilizing the vehicle.
TCC Lockup / Forced TCC Lockup
The TCU locks up the torque converter clutch during cruising conditions for improved fuel economy
and to allow the transmission fluid to cool. In order for the TCC to lock, several conditions must be
met: - Transmission fluid warmed up
- Transmission above 3rd gear (unless transmission fluid is overheated)
- Vehicle speed above user adjustable minimum (see MIN TCC LOCK setting)
- Throttle above idle position
- Throttle below user adjustable maximum (see MAX TCC TPS setting)
NOTE: TCC lockup can be completely disabled if desired by entering an unobtainable speed for the
MIN TCC LOCK setting. The vehicle would then always be below the minimum speed for TCC
lockup.
There is also a Forced TCC Lockup mode. When the TCC APPLY wire is grounded, the TCC will
lock without the normal requirements being met. The only conditions that must be met are in place to
prevent stalling if this feature is accidentally turned on or left on:
- Transmission above 1st gear
- Vehicle speed above 10 mph
TCI® 6x Six-Speed in Drive
Just like the 4L60E and 4L80E transmissions, when the TCI® 6x Six-Speed transmission is operated
with the shift lever in the L3/Drive position, it uses 3 forward gears.
L2 Shift Lever Position
In normal operation, the TCU controls shifting and the transmission will upshift through the gears at
the appropriate speeds up to the shift lever position. For example, it will upshift until it gets to 3rd gear
when the shift lever is in the L3/Drive position. Putting the shift lever into the L2 position is a special
case. Instead of just being the upper limit for gear selection, it actually puts the transmission directly
into 2nd gear. This can be useful in special situations. For example, it may help reduce wheel spin
when pulling away from a stop on a slippery surface.
Speed Checks
There are vehicle speed checks in place to protect the drive train if a gear is selected (either with the
shift lever or with manual bump up / bump down shifting) that is too low for the current vehicle speed.
In this case, the TCU will not electronically execute the requested downshift. However, due to the
mechanical / hydraulic makeup of a transmission, the TCU does not always have absolute control over
gear selection. For example, moving the shift lever on a TCI® 6x Six-Speed transmission from
Overdrive to L3/Drive while the transmission is in 6th gear will result in a downshift regardless of
vehicle speed. So even though the TCU is programmed to do all it can to protect the drive train, the

driver must still use caution and common sense when requesting a downshift. Ultimately, the well
being of the vehicle and its occupants is the driver’s responsibility.
LED
The LED on the front face of the TCU operates as follows:
On solid - TCU powered up and working normally.
Rapid flashing - An error code has been set. Select ERROR CODES from the main menu to
check and clear error codes.
Slow flashing - TCU is in Flash Mode. Make sure the FLASH ENABLE wire is not grounded,
then key off, wait about 10 seconds and key back on.
TRANSMISSION INFORMATION
Transmission Troubleshooting
The EZ-TCU™ system relies on properly functioning components within the transmission to do its job
correctly. Some of those components can be checked by measuring resistance between the appropriate
terminals in the TCU’s main connector. To perform the testing, disconnect the main connector from
the TCU and probe the pairs of terminals with a multi-meter set to measure resistance. Terminal
numbers are molded into the main connector.
Terminals at… Ohms (at 70°F)
Component
(4L60E / 4L80E / 6x) TCU Trans 4L60E 4L80E 6x
Shift Solenoid A 4 13 E A 20 - 30
Shift Solenoid B 4 14 E B 20 - 30
Force Motor 1 10 D C 3.5 – 8.0
------ / TCC / TCC 4 11 E S n/a 10 - 15 10 - 15
TCC / ------ / ------ 4 20 E T 20 - 30 n/a n/a
TCC PWM / ------ / Sol. C 4 15 E U 10 – 15 n/a 20 - 30
Transmission Retrofit Details
The mechanical portion of this transmission swap is similar to swapping a 700R4 into an older model
vehicle that was originally equipped with a Powerglide, TH350 or TH400 transmission. Depending on
the application, the driveshaft may need to be lengthened or shortened. The crossmember may need to
be moved and the transmission mount, bellhousing and shift linkage may need to be modified. The
starter may need to be replaced as well. If you are installing a high performance aftermarket converter,
you may even need to drill the flexplate holes oversize in order to accommodate larger-than-factory
bolts. Be sure to check this before attempting the swap. (It's a hassle to have to remove the
transmission from the car simply because the converter bolts would not go through the flexplate!)

Use the dimensions listed below to determine the proper amount to move your crossmember and the
amount to have the driveshaft shortened or lengthened.
Transmission Overall
Length
Distance to
Crossmember
Mount
Bellhousing Bolt
Pattern
4L60E (1993-1996)
4L60E/4L65E (1996-later w/ removable
bellhousing, non-LS1)
4L60E/4L65E (1998-later w/ LS1)
30 ¾"
30 ¾"
31 5/32"
22 ½"
23 3/16"
23 19/32"
Chevy
Chevy
Chevy
4L80E/4L85E (Std. 2WD)
4L80E/4L85E (HD 2WD)
4L80E/4L85E (HD long)
32 11/16"
31 15/16"
33"
30 3/8"
30 3/8"
30 3/8"
Chevy
Chevy
Chevy
700R4/4L60 30 ¾" 22 ½" Chevy
2004R 27 11/16" 27" Chevy, BOP, Fit-all*
Powerglide 27 11/16" 20
9/16" Chevy, BOP
TH350 (6" tailshaft)
TH350 (9" tailshaft)
TH350 (12" tailshaft)
27 11/16"
30 11/16"
33 27/32"
20 3/8"
20 3/8"
20 3/8"
Chevy, BOP, Fit-all*
Chevy, BOP, Fit-all*
Chevy, BOP, Fit-all*
TH400 (C tailshaft)
TH400 (D tailshaft)
TH400 (13" tailshaft)
28 3/8"
33 27/32"
37 7/8"
26 15/16"
27 15/16"
27 21/32"
Chevy, BOP
Chevy, BOP
Chevy, BOP
* Fit-all refers to a bellhousing configured to accept either a Chevy or BOP engine.
(BOP = Buick, Olds, Pontiac, Cadillac)
Both the 4L60E/4L65E and 4L80E/4L85E have Chevy bellhousing bolt patterns. TCI® has a full line
of adapters to allow these transmissions to be bolted up to Buick, Olds, Pontiac engines as well as
popular engines from Ford and Chrysler as well.
Additional 4L60E/4L65E Notes
Header / Exhaust Clearance
There are several different bellhousing configurations for the 4L60E/4L65E transmission. The earlier
models (1993-1996) have an integral bellhousing identical to the 700R4. In some cases, the dust cover
mounting ears will have to be cut off to accommodate header collectors. This can easily be
accomplished with a hacksaw. The later models (1996-later) have a fully circumferential, bolt-on
bellhousing. It is important to use the correct bellhousing for your application. The LS1-style
4L60E/4L65E transmissions have a unique bellhousing and input shaft. These types are not direct
replacements for the non-LS1 applications.
Some headers will interfere with the starter hump on the bolt-on bellhousings. It may be necessary to
either dimple the header or cut off the starter hump.

Starter Clearance
The bellhousing may require modifications if you intend to use a stock starter. As an alternative to
modifying the bellhousing, you may choose to install a TCI® starter.
Shift Lever
Many 1996-later, two-piece case transmissions (primarily trucks) have a shift lever that is about 1”
longer than the early-style found on 700R4, TH350 and TH400.
Cooler Lines
Your existing lines may have to be bent to connect to a 1996-later, two-piece case transmission. These
units have fittings that are parallel to the ground instead of being angled down. You may also need to
change the case fittings as many 1996-later transmissions are equipped with the factory quick-connect
style.
NOTE: Do not use Teflon® tape if replacing cooler fittings. It can cause the case to crack due to over
tightening.