VEMS v3 ECU User manual

12/16/2012
Installation Instructions and Setup Guide | Jason Russell

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Table of Contents
Initial Information ........................................................................................................................................ 4
Legal isclaimer ....................................................................................................................................... 4
Planning Guide ......................................................................................................................................... 4
Getting Started ............................................................................................................................................ 5
Power up on the bench ............................................................................................................................ 5
Grounds ................................................................................................................................................... 5
Power Grounds .................................................................................................................................. 5
Sensor Ground ................................................................................................................................... 6
+12V Supply ............................................................................................................................................. 6
Connecting serial port .............................................................................................................................. 7
Connect essential sensors ............................................................................................................................ 8
Crank Trigger ............................................................................................................................................ 8
Connecting the primary trigger (Crank) ................................................................................................... 8
Configuring the crank trigger ................................................................................................................... 9
Connecting the Secondary Trigger (Cam) ................................................................................................. 9
Configuring the Secondary Trigger (Cam) .............................................................................................. 10
Temperature Sensors ............................................................................................................................. 10
IAT – Inlet Air Temperature .............................................................................................................. 10
CLT – Coolant Temperature .............................................................................................................. 10
TPS – Throttle Position Sensor ............................................................................................................... 11
Configuring the TPS sensor ................................................................................................................... 11
Secondary Sensors ..................................................................................................................................... 12
WBO2 ..................................................................................................................................................... 12
EGT ........................................................................................................................................................ 12
Knock .................................................................................................................................................... 13
Primary Outputs ........................................................................................................................................ 14
Connecting Ignition Components .......................................................................................................... 14
Example coil connections ................................................................................................................ 16

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Single coil ......................................................................................................................................... 16
Coil pack .......................................................................................................................................... 17
Coil on plug (COP) ............................................................................................................................ 18
Using the Stepper Motor river to control Ignition ............................................................................... 18
Ignition Setup ......................................................................................................................................... 19
Index engine .......................................................................................................................................... 20
Injector Model ....................................................................................................................................... 21
Injector Outputs ..................................................................................................................................... 22
Secondary Outputs ................................................................................................................................ 22
Inputs ......................................................................................................................................................... 23
Misc Outputs ............................................................................................................................................. 23
List of Authorized Resellers ........................................................................................................................ 24
Appendix .................................................................................................................................................... 25
Connector pinout ................................................................................................................................... 25

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Initial Information
Legal Disclaimer
The authors, advisors, manufacturers, website maintainers or anyone involved in shipping or
support are NOT responsible for consequences - even if it's proven that any injury, damage or
inconvenience is directly caused by their advice.
No applicability of the hardware, firmware, other software, instructions, or documentation for a
particular purpose is claimed.
ll installers, diy-ers, and users are responsible for testing, installing, programming and using
their units.
You understand that modifications are suitable to ruin your engine. Modifications usually
invalidate any emission related certification, and most often invalidates the license to use the
equipment (eg. car, snowmobile) at all. For off-road use only.
You understand that like any electronic or mechanical equipment, they can fail. Failing
equipment in a vehicle can be fatal.
You are responsible for compliance with the laws of your jurisdiction.
If any provision of these Terms and Conditions is found to be invalid by any court having
competent jurisdiction, the invalidity of such provision shall not affect the validity of the
remaining provisions of these Terms and Conditions, which shall remain in full force and effect.
No waiver of any of these Terms and Conditions shall be deemed a further or continuing waiver
of such term or condition or any other term or condition.
In short, we can not cover every conceivable scenario. Please be aware of the consequences and plan
accordingly. Be safe!
Planning Guide
Things you need to know before ordering an ECU:
•Crank trigger type
•Trigger wheel
•Cam trigger type (if applicable)
•Number of Cylinders
•Number of coils
•Type of coil (logic level or high current)
•Number of fuel injectors
•Type of fuel injectors (high impedance or low impedance)

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•Type and value of temperature sensors
•Any accessories or options you may want
•MAP sensor range (2.5 bar, 3bar, 4bar, or external)
Order info, options, ignition outputs, EGT, Knock,
Getting Started
Initial Power up
Connect all the grounds
Grounds
From the outset it cannot be stressed enough just how important grounding is. 95% of all noise
issues are due to poor grounding.
Grounds need to be connected with a clean connection and thick wire, and near the ECU. There
are two branches so the fluctuation of power signals do not interfere with the measured signals
(most importantly: the trigger):
Power Ground handles the noisy and high currents generated by driving injectors, coils and
solenoids.
Sensor Ground handles 0 to 5v signals from crank, throttle and temperature sensors. VR-trigger
sensor at low RPM (cranking) is the most sensitive to noise.
The GROUND rules:
•connect Sensor GN (EC36 pin 26) and the 4 Power GN s with short (preferably 10..15cm, max
20..30cm from EC36), strong (preferably 0.75mm2 or stronger) wires.
oPower Grounds & Sensor Grounds MUST terminate at the same point - Common
Ground. Run the wires into a single ring crimp so that there is no chance of one ground
coming free.
•Keep the Power Ground connection (EC36 pin26, 5,21,22,32) pins to the Common Ground point
short max 0.1 .. 0.3m,
ouse strong wires. Preferably all 5 wires should be 0.75mm2 or stronger. Some
installations (particularly with no PWM-ing) could tolerate somewhat longer wires, but
why risk it ? (ground problems are like ghosts, very hard to track down). The length of
wire(s) from this common ground point to battery / chassis can be longer (and usually
are long). Strong wires must be preferred (total 4mm2), and not longer than necessary.
But at least nowhere near as sensitive as the wires right at the ECU.
oconnect the ground of the sensors to the Common Ground point or to the sensor ground
branch, that is EC36pin26.
oConnect Power Grounds to the Common Ground point, or anywhere you like (except the
sensor-ground branch)
•Failure to connect Sensor Ground and Power Ground will damage your VEMS. Even on the test
bench !

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Power Grounds
lso called as "GND5" in some documents
•EC36-pin5 to Common Ground
•EC36-pin21 to Common Ground
•EC36-pin32 to Common Ground
•EC36-pin22 to Common Ground
Sensor Ground
•EC36-pin26 to Common Ground. NOTE: Sensor Ground pin has many connections (CAS, TPS, IAT,
CLT ...) make provision for this in your wiring loom.
+12V Suppl
•EC36-pin25 3A Fused +12v supply
Note that if you have moved the battery to the rear of the car you may want to run separate wires for
the starter/alternator and for the cars electrical system to the battery. Otherwise the several meters long
cable will cause a significant voltage drop during cranking that will cause the ECU to reset when the
battery starts to run low. This may prevent the car from starting even if the engine cranks over.
Once you have connected and checked the continuity of ground you can connect your VEMS
unit to the EC36 plug and apply the power supply. There is little point in connecting power until
the serial connector is added though.

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Connect the serial port
Connecting serial port
To allow the connection of the VEMS unit to your PC a serial port plug must be connected as
follows.
•EC18-pin14 to SUB9-pin3
•EC18-pin15 to SUB9-pin2
•EC36-pin26 to SUB9-pin5 (GN ).
Start VemsTune and test connectivit
If you don't already have VemsTune, you can download it from here: http://www.vems.hu/vt
Always stay up to date with VemsTune. This is especially important when updating the firmware on the
ECU. Older VemsTune releases may not understand and properly handle the newer firmwares.

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Start VemsTune, select the COM port that is connected to the ECU. You may notice that a TCP connection
is also supported if you have a TCP serial adapter.
Connect essential sensors
Crank Trigger
The trigger is the engine management system's most fundamental sensor, without one VEMS
cannot calculate engine speed or crank angle. If you are connecting VEMS to an engine that has
an existing engine management system, if not then a triggering method will need to be put in
place.
The simplest type of trigger is to use the existing distributor to provide a pulse for each cylinder.
This type of trigger is more than adequate for driving ignition through a distributor and batch fire
injection.
Connecting the primar trigger (Crank)
Magnetic sensor / Variable reluctance (VR)
Mechanical considerations
If you are fitting a crank sensor to an engine it is advisable to use a hall sensor rather than
a VR sensor. They are more forgiving to wheel design and noise. Generally, VR sensors
should be used in applications utilizing factory sensors.
The VR sensing circuitry is very sensitive to electrical noise, shielded cable (coax) must be used
and good grounding is vital.
•EC36-pin27 VR+ Note that some other ECUs trigger on positive-going edge so their schematic
might mark the + and GN swapped: so don't blindly follow naming from autodata pinout or
some schematic, keep in mind that + and - might need to be swapped. Measure to be sure:
InputTrigger/TriggerLog
•EC36-pin26 VR-
Shielding should be grounded to engine block close to the VR Sensor.
Hall Sensor

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VEMS is available configured for Hall sensors, these are more noise tolerant and require a +5V
(or sometimes +12V for some sensors) supply.
•EC36-pin27 Hall signal
•EC36-pin26 Ground
•EC36-pin28 +5V
Configuring the crank trigger
Crank Trigger configuration can be accessed from the Base Setup menu in the Primary Trigger Settings
option. Trigger Edge should normally be rising for VR, falling for Hall. A hall sensor may be configured for
rising if the trigger edge needs to be moved the width of a tooth, but this is generally not needed. Select
the trigger type. Missing tooth is most common and includes 36-1, 60-2, and other common wheels with
missing teeth. If the wheel doesn't have any missing teeth, that is coil-type. Missing tooth type should be
n-1 if there is one missing tooth on the wheel, and n-2 if there are two missing teeth on the wheel.
Number of teeth on the wheel is the number of remaining teeth. 58 for a 60-2 wheel for example. There
are very useful defaults at the bottom of the window to set up your trigger wheel. T C after the trigger
needs to be measured and set with a timing light. Use the Tools → Ignition Lock menu item to set your
timing at 0.25 degrees and crank the engine and verify cylinder 1 fires at T C. Adjust the T C after the
trigger until correct. You may need to change the First Trigger Tooth if the T C after the trigger value gets
below 40 degrees or above 100 degres. 60 degrees is a good value to aim for. Pressing F1 on the Primary
Trigger Settings window, or any window in VemsTune, will give you some detailed help with more
specific information.
Connecting the Secondar Trigger (Cam)
VR type

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Hall Effect Type
Configuring the Secondar Trigger (Cam)
The secondary trigger is most often used for cam sync. This can be configured on the Base Setup menu
under the Secondary Trigger Settings item. Mode is either isabled or Cam-Sync except under special
circumstances. Use rising edge for VR sensor. Either edge can be used for a Hall sensor, but typically
falling is used. Event at Bad Trigger Position is the last common item to configure. It is recommended to
set it to Just Show. You can have it disable injection if you wish, but it is not recommended.
Temperature Sensors
VEMS uses two temperature sensors: Inlet Air Temperature which is used in speed/density systems to
calculate the amount of fuel required. And Coolant Temperature which is used to meter the required amount
of warm up fuel enrichment.

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MAT – Manifold Air Temperature
Also known as IAT, Inlet Air Temperature
•EC36 pin2 Signal
•EC36 pin26 Ground
You can configure a custom sensor curve if needed under the Inputs menu with the MAT sensor curve
item.

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CLT – Coolant Temperature
•EC36 pin14 Signal
•EC36 pin26 Ground
You can configure a custom sensor curve if needed under the Inputs menu with the Coolant Sensor
Curve item.

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The standard Bosch CLT sensor curve is included in the efaults section, and is close to many other
sensors.
TPS – Throttle Position Sensor
The throttle position sensor is used by VEMS to provide fuel requirements in Alpha N configuration and
acceleration enrichment.
•EC36 pin29 TPS (+5v) out
•EC36 pin1 Wiper out (0 5v)
•EC36 pin26 Ground
Configuring the TPS sensor
The throttle position sensor is used by VEMS to provide fuel requirements in Alpha N configuration and
acceleration enrichment.
•EC36 pin29 TPS (+5v) out
•EC36 pin1 Wiper out (0 5v)
•EC36 pin26 Ground

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Secondar Sensors
WBO2
•EC18 pin13 to WB6 pin1 (Nerst Cell Signal)
•EC18 pin7 to WB6 pin5 (WBO2 Pump )
•EC18 pin18 to WB6 pin4 (WBO2 Heater)
•EC18 pin9 to WB6 pin6 (WBO2 Pump+)
EGT
There are 2 standards that are the most common. You must make sure the + and are connected properly.
Everything is the same between the standards other than the colors. They are fully interchangeable.
British standard American Standard
connector green yellow
wire insulation green yellow
+ wire green yellow
- wire white red

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Knock
Tuning the knock sensor is not a trivial task, and can take a considerable amount if time and
experimentation to get right. Configuring the knock dynamics of an engine and over comming issues of
mechanical noise can take a lot of time and effort, therefore you must not rely on the knock sensor to
prevent knock, this can only be done by sensible tuning and using the correct octane fuel for your
application.
Although VEMS will work with a variety of knock sensors the ones that have been tried and tested are
Bosch, although other 2 or three wire sensors may work.Do not use a single wire knock sensor as they use
the common ground of the block to create the circuit, using the block will inject too much noise into the
sensitive knock circuitry.

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•EC18 pin3 Knock sensor signal (Bosch type pin1)
•EC18 pin2 Knock sensor ground (Bosch type pin2)
Some Bosch type sensors are 3 wire type, pin3 is the cable's shield. On either type of sensor the shield
should be grounded near or on the engine block.
Primar Outputs
NOTE: VEMS acts as a switch between the Component (injector, relay, ignition coil) and ground. VEMS
does not provide the power to these components.
Connecting Ignition Components
The unit can be ordered with one of five possible Ignition Channel Options.
Option 8 All 8 channels are high current control channels: (most common)
Option 0 All 8 ignition channels are using logic level(+5v) control for coils that have built in igniters or
systems where you wish to use an existing igniter pack:

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Option 2+6 Two channels are high current, the other 6 are logic level:
Option 4+4 Four high current channels, Four logic level:
Option 6+2 Six high current channels, two logic level:

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Alternative Connection If you are using an external ignition module/igniter pack you can also use the
Stepper Motor outputs as control channels:
This method is suitable for 4 cylinder COP/CNP or 4, 6 and 8 cylinder wasted spark.
Example coil connections
The following connections suggest the pin numbers as a suggestion only. The actual connections will
depend on the Ignition Channel Options as above.
Single coil
In some instances you will want to keep the distributor, in this case VEMS can be configured to use the
original coil as shown.

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Coil pack
Connecting a two coil (4 cylinder wasted spark)
Additional coil packs, for applications such as 8 cylinder wasted spark

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Coil on plug (COP)
Individual Coil connections are shown, the pins connect to the negative ' ' side of the coil.
Using the Stepper Motor Driver to control Ignition
In some cases it has been found that we need to drive external ignition amplifiers (ignitors) using the higher
current stepper motor driver.
If you have been using the EC36 plug, the wires must be swapped from the Ingition pins on the EC36 plug
and moved to the EC18 plug as follow