Kohler KG2204 Assembly instructions

TP-6903 5/16a
Engine Fuel System and
Diagnostic Code Troubleshooting
Engine Models:
KG2204
KG2204T
Propane, Liquefied Petroleum Gas (LPG)
and Natural Gas
(
NG
)
Fueled
Service

2 Product Identification Information TP-6903 5/16a
California Proposition 65
WARNING
Engine exhaust from this product contains chemicals
known to the State of California to cause cancer, birth
defects, or other reproductive harm.
Product Identification Information
Product identification numbers determine service
parts. Record the product identification numbers in
the spaces below immediately after unpacking the
products so that the numbers are readily available for
future reference. Record field-installed kit numbers
after installing the kits.
Engine Identification
Record the product identification information from
the engine nameplate.
Manufacturer_______________________________
Model Designation___________________________
Serial Number ______________________________

TP-6903 5/16a Table of Contents
Table of Contents
Product Identification Information............................................................................................................................................2
Table of Contents.......................................................................................................................................................................3
Safety Precautions and Instructions........................................................................................................................................5
Introduction .........................................................................................................................................................................9
Service Assistance...................................................................................................................................................................10
Section 1Fuel System Overview.................................................................................................................................11
1.1.Introduction .......................................................................................................................................11
1.2.Air-Fuel Mixer....................................................................................................................................13
1.3.Charge Air Cooler (KG2204T only) ..................................................................................................13
1.4.Coolant Temperature Sensor ............................................................................................................13
1.5.Crankshaft Position (CKP) Sensor ....................................................................................................14
1.6.Electronic Control Module .................................................................................................................14
1.7.Fuel Control Valve.............................................................................................................................15
1.8.Fuel Pressure Regulator ...................................................................................................................15
1.9.Fuel Shut-Off Valves .........................................................................................................................16
1.10.Heated Exhaust Gas Oxygen (HEGO) Sensor..................................................................................16
1.11.Ignition System..................................................................................................................................17
1.12.MAP and TMAP Sensors ..................................................................................................................17
1.13.Oil Pressure Sender..........................................................................................................................18
1.14.Throttle Body.....................................................................................................................................19
1.15.Throttle Position (TP) Sensor ............................................................................................................19
1.16.Turbocharger (KG2204T only) ..........................................................................................................20
1.17.Turbocharger Oil Lines (KG2204T only) ...........................................................................................20
Section 2Diagnostic Troubleshooting Codes...........................................................................................................21
2.1.Introduction .......................................................................................................................................21
2.2.Spectrum Diagnostic Scan Tool (DST) .............................................................................................21
Section 3Fuel System Troubleshooting ....................................................................................................................45
3.1.Fuel System Intermittent Problems ...................................................................................................47
3.2.Fuel System Basic Checks................................................................................................................47
3.3.No Start.............................................................................................................................................49
3.4.Hard Start..........................................................................................................................................50
3.5.Cuts Out and Misses.........................................................................................................................51
3.6.Hesitation, Sag, or Stumble...............................................................................................................52
3.7.Backfire .............................................................................................................................................53
3.8.Lack of Power or Sluggishness .........................................................................................................54
3.9.Poor Fuel Economy...........................................................................................................................55
3.10.Rough, Unstable, or Incorrect Engine Speed and Stalling ................................................................56
3.11.Hunting and Surging .........................................................................................................................57
Section 4Electrical System and Sensor Troubleshooting .......................................................................................59
4.1.Introduction .......................................................................................................................................61
4.2.Powering the ECM ............................................................................................................................61

4 Table of Contents TP-6903 5/16a
4.3.Coolant Temperature Sensor Troubleshooting .................................................................................62
4.4.Crankshaft Position (CKP) Sensor Troubleshooting .........................................................................64
4.5.Electrical System Intermittent Problems............................................................................................66
4.6.Fuel Control Valve Troubleshooting ..................................................................................................67
4.7.Heated Exhaust Gas Oxygen (HEGO) Sensor Troubleshooting .......................................................69
4.8.Ignition Coil Troubleshooting.............................................................................................................72
4.9.Oil Pressure Sender Troubleshooting ...............................................................................................75
4.10.Temperature Manifold Pressure (TMAP) and MAP Sensor Troubleshooting ....................................77
4.11.Throttle Position (TP) Sensor Troubleshooting .................................................................................79
Section 5Installation and Removal Procedures........................................................................................................83
5.1.Air-Fuel Mixer, Adapter, and Throttle Body Assembly.......................................................................85
5.2.Coolant Temperature (CT) Sensor....................................................................................................88
5.3.Crankshaft Position (CKP) Sensor ....................................................................................................90
5.4.Electronic Control Module (ECM)......................................................................................................91
5.5.Fuel Control Valve.............................................................................................................................92
5.6.Fuel Pressure Regulator ...................................................................................................................93
5.7.Heated Exhaust Gas Oxygen Sensor (HEGO)..................................................................................95
5.8.Ignition Coil .......................................................................................................................................96
5.9.Oil Pressure Sender..........................................................................................................................97
5.10.Temperature Manifold Pressure (TMAP) Sensor ..............................................................................98
5.11.Manifold Pressure (MAP) Sensor, KG2204T.....................................................................................99
Appendix A Torque Specifications......................................................................................................................................101
Appendix B Abbreviations ...................................................................................................................................................103

TP-6903 5/16a Safety Precautions and Instructions 5
Safety Precautions and Instructions
Read and follow all safety precautions
and instructions. SAVE THESE
INSTRUCTIONS.
This manual has several types of safety
precautions and instructions: Danger,
Warning, Caution, and Notice.
DANGER
Danger indicates the presence of a
hazard that will cause severe personal
injury, death, or substantial property
damage.
WARNING
Warning indicates the presence of a
hazard that can cause severe personal
injury, death, or substantial property
damage.
CAUTION
Caution indicates the presence of a
hazard that will or can cause minor
personal injury or property damage.
NOTICE
Notice communicates installation,
operation, or maintenance information
that is safety related but not hazard
related.
Safety decals affixed to the equipment in
prominent places alert the operator or
service technician to potential hazards
and explain how to act safely. The
decals are shown throughout this
publication to improve operator
recognition. Replace missing or
damaged decals.
Accidental Starting
WARNING
Accidental starts can cause
severe injury or death.
Disconnect and ground spark
plug leads before servicing.
Before working on engine or
equipment, disable engine as
follows: 1) Disconnect spark plug
leads. 2) Disconnect negative (–)
battery cable from battery.
Before disconnecting negative (–)
ground cable, make sure all switches
are OFF. If ON, a spark will occur at
the ground cable terminal which
could cause an explosion if hydrogen
gas or LPG/NG fuel vapors are
present.
Engine Backfire/Flash
Fire
WARNING
Risk of Fire. Can cause severe
injury or death.
Do not smoke or permit flames or
sparks near fuels or the fuel system.
Servicing the fuel system. A flash
fire can cause severe injury or
death. Do not smoke or permit
flames or sparks near the
carburetor, fuel line, fuel filter, fuel
pump, or other potential sources of
spilled fuels or fuel vapors. Catch
fuels in an approved container when
removing the fuel line or carburetor.
Servicing the air cleaner. A
sudden backfire can cause severe
injury or death. Do not operate the
engine with the air cleaner removed.
Troubleshooting and/or repairing
the sensors or the ECM. A
backfire due to an open fuel shut-
off valve can cause severe injury
or death. If power is supplied to the
shut-off valve during ECM or sensor
troubleshooting, fuel may enter the
air intake manifold or the air cleaner
and cause a backfire. Make sure that
the fuel supply is turned OFF and
that the fuel shut-off valves are
DISCONNECTED from the power
source BEFORE turning the ECM
power on.

6 Safety Precautions and Instructions TP-6903 5/16a
Exhaust System
WARNING
Carbon monoxide can cause
severe nausea, fainting, or death.
Avoid inhaling exhaust fumes.
Engine exhaust gases contain
poisonous carbon monoxide.
Carbon monoxide is odorless,
colorless, and can cause death if
inhaled.
Fuel System
WARNING
Explosive fuel vapors. Can cause
severe injury or death.
Use extreme care when handling,
storing, and using fuels.
Gas fuel leaks. Explosive fuel vapors
can cause severe injury or death.
Fuel leakage can cause an
explosion. Check the LPG vapor or
natural gas fuel system for leakage
by using a soap and water solution
with the fuel system test pressurized
to 6–8 ounces per square inch (10–
14 inches water column). Do not use
a soap solution containing either
ammonia or chlorine because both
prevent bubble formation. A
successful test depends on the
ability of the solution to bubble.
WARNING
Explosive fuel can cause fires and
severe burns.
If a gaseous odor is detected,
ventilate the area and contact an
authorized service technician.
LPG (Liquefied Petroleum Gas) is
extremely flammable and tends to
settle in low areas where a spark
or flame could ignite the gas. Do
not start or operate this engine in a
poorly ventilated area where leaking
gas could accumulate and endanger
the safety of persons in the area.
NG (Natural Gas) is extremely
flammable, is lighter than air, and
rises. Do not start or operate this
engine in a poorly ventilated area
where leaking gas could accumulate
and endanger the safety of persons
in the area.
To ensure personal safety,
installation and repair of LPG/NG
fuel supply systems must be
performed only by qualified LPG/NG
system technicians. Improperly
installed and maintained LPG/NG
equipment could cause the fuel
supply system or other components
to malfunction, causing gas leaks.
Observe federal, state, and local
laws governing LPG/NG fuel,
storage, and systems.
Hazardous
Voltage/Moving Parts
WARNING
Electrical shock can cause injury.
Do not touch wires while engine is
running.
WARNING
Avoid possible death or serious
injury! Pinch and entanglement
hazards!
Never check drive belt tension while
the engine is running.
WARNING
Rotating parts can cause severe
injury.
Stay away while the engine is in
operation.
Keep hands, feet, hair, and clothing
away from all moving parts to
prevent injury. Never operate the
engine with covers, shrouds, or
guards removed.

TP-6903 5/16a Safety Precautions and Instructions 7
WARNING
Spring-loaded parts. Can cause
severe personal injury or property
damage.
Wear protective goggles when
servicing spring-loaded parts. Hold
parts securely during disassembly.
WARNING
Airborne particles. Can cause
severe injury or blindness.
Wear protective goggles and
clothing when using power tools,
hand tools, or compressed air.
Hot Parts
WARNING
Hot parts can cause severe burns.
Do not touch engine while
operating or just after stopping.
Never operate engine with heat
shields or guards removed.
Servicing the exhaust system. Hot
parts can cause severe injury or
death.
Do not touch hot engine parts. The
engine and exhaust system
components become extremely hot
during operation.
WARNING
Hot coolant and steam. Can cause
severe injury or death.
Before removing the pressure cap,
stop the engine and allow it to cool.
Then loosen the pressure cap to
relieve pressure.
WARNING
Handling caustic engine fluids
and chemical products can cause
severe chemical burns, nausea,
fainting, or death.
Most chemicals such as used engine
oil, antifreeze/coolant, rustproofing
agent, inhibiting oil, degreasing
agent, spray paint, and adhesives
are hazardous to health. Read and
follow the user information found on
the packaging. Avoid inhalation and
skin contact. Use only in well-
ventilated areas and use a protective
mask when spraying. Store engine
fluids and chemical products in a
locked cabinet. Contact your local
recycling center for disposal
information and locations.
Used engine oil. Contact with
used engine oil may cause severe
skin irritation. Repeated and
prolonged skin exposure may
have other health risks. Used
engine oil is a suspected
carcinogen. Avoid contact with skin.
Thoroughly wash your hands and
nails with soap and water shortly
after handling used engine oil. Wash
or dispose of clothing or rags
containing used engine oil. Dispose
of used engine oil in accordance with
applicable laws and regulations.
Contact your local recycling center
for disposal information and
locations.

8 Safety Precautions and Instructions TP-6903 5/16a
Notes

TP-6903 5/16a Introduction 9
Introduction
This manual applies to the Kohler Model
KG2204/KG2204T 2.2L engine. The purpose of this
manual is to provide an understanding of the fuel
system and instructions to troubleshoot the fuel system
and sensors.
To troubleshoot the fuel system using the instructions
in this manual, use the following steps:
Connect to the ECM, electronic control module, to
read any logged Diagnostic Troubleshooting
Codes (DTC).
a. A laptop with Spectrum software and a
Kvaser® cable are required to connect to the
ECM.
Note: Spectrum is a diagnostic scan tool (DST)
software program from IMPCO® Technologies,
Inc. Refer to the software instruction manual for
installation and operation. See Section 2.2 for
more information.
Refer to Section 2, Diagnostic Troubleshooting
Codes in this manual to look up the
recommended troubleshooting steps for a DTC.
The DTC chart lists the components that are most
likely causing the DTC fault and the corrective
actions.
In Section 3, Fuel System Troubleshooting , and
Section 4, Electrical System and Sensor
Troubleshooting, follow the troubleshooting steps
indicated in the DTC chart.
If the troubleshooting steps require a component
to be replaced, refer to Section 5, Installation
and Removal Procedures.
Information in this publication represents data
available at the time of print. Kohler Co. reserves the
right to change this publication and the products
represented without notice and without any obligation
or liability whatsoever.
Read this manual and carefully follow all procedures
and safety precautions to ensure proper equipment
operation and to avoid bodily injury. Read and follow
the Safety Precautions and Instructions section at the
beginning of this manual. Keep this manual with the
equipment for future reference.
Unless otherwise specified, all units of measurement
are metric, followed by the Imperial (U.S.) equivalent.
IMPCO is a registered trademark brand of IMPCO Technologies,
Inc.
KVASER is a registered trademark of TIMEGALACTIC AB.
List of Related Materials
Figure 1-1 identifies related literature available for the
KG2204/KG2204T engine covered in this manual.
Figure 1-1 Related Literature
Literature Type Part Number
Operation Manual,
KG2204/KG2204T Engine
TP-6901
Service Manual,
KG2204/KG2204T Engine
Mechanical
TP-6902
Parts Catalog,
KG2204/KG2204T Engine TP-6904

10 Service Assistance TP-6903 5/16a
Service Assistance
For professional advice and conscientious service,
please
contact your nearest Kohler distributor or dealer.
Consult the Yellow Pages under the
heading Generators–Electric.
Visit the Kohler Power Systems website at
KOHLERPower.com.

Look at the labels and decals on your Kohler
product or review the appropriate literature or
documents included with the product.
Call toll free in the US and Canada 1-800-
544-2444.

Outside the US and Canada, call the nearest
regional office.
Headquarters Europe, Middle East,
Africa
(EMEA)
Kohler Power Systems Netherlands B.V.
Kristallaan 1
4761 ZC Zevenbergen
The Netherlands
Phone: [phone]
Fax: [phone]
Asia
Pacific
Power Systems Asia Pacific Regional Office
Singapore, Republic of Singapore
Phone: [phone]
Fax: [phone]
China
North China Regional Office, Beijing
Phone: [phone]
(86) 10 6518 7951
(86) 10 6518 7952
Fax: [phone]
East China Regional Office, Shanghai
Phone: [phone]
Fax: [phone]
India, Bangladesh, Sri Lanka
India Regional Office
Bangalore, India
Phone: [phone]
(91) 80 3366231
Fax: [phone]
Japan, Korea
North Asia Regional Office
Tokyo, Japan
Phone: [phone]
Fax: [phone]
Latin America
Latin America Regional Office
Lakeland, Florida, USA
Phone: [phone]
Fax: [phone]
Fax: [phone]

TP-6903 5/16a Fuel System Overview 11
Section 1 Fuel System Overview
1.1. Introduction
The KG2204 and KG2204T are four-stroke internal
combustion engines certified to operate on Natural Gas
(NG) or Liquefied Petroleum Gas (LPG). System
configuration is factory preset for NG and can be reset
for LPG applications.
At startup, the engine ECM operates in an open-loop
fuel state, which means fuel delivery is based on a fuel
calibration program internal to the ECM. The program
controls the fuel control valve to achieve stoichiometric
combustion.
After the oxygen sensor heats up and the engine
coolant temperature reaches a predetermined level,
the ECM calibration program transitions to a closed-
loop mode. The air/fuel delivery is based on the
oxygen sensor input and engine sensor data. The
engine ECM uses this data to regulate the fuel control
valve (FCV), which is used as a fuel trim device and is
located at the intake manifold. The FCV is an
electrically controlled engine vacuum switch. When
the FCV is energized, the valve opens and, through a
vacuum line connection to the fuel regulator, creates a
vacuum on the fuel pressure regulator. This vacuum
causes the regulator’s diaphragm to close, decreasing
the fuel delivered to the intake. The FCV signal would
be considered a modulated signal sent by the ECM to
obtain stoichiometric combustion.
Figure 1-1 Fuel System Overview, KG2204 Naturally Aspirated Engine
1. HEGO sensor
2. TMAP sensor
3. Fuel control valve
4. Throttle body
5. Air-fuel mixer
6. Coolant temperature sensor
7. Crankshaft position sensor
8. Exhaust
9. Ignition coil
10. Oil pressure sender
11. Fuel pressure regulator
12. Fuel shut-off valve
13. ECM
14. Air cleaner
15. Air intake
1
2 3
4
5
6
7
8
9
10
12
13
11
14
15

12 Service Assistance TP-6903 5/16a
Figure 1-2 Fuel System Overview, KG2204T Turbocharged Engine
1. Fuel pressure regulator
2. Air-fuel mixer
3. Turbocharger
4. TMAP sensor
5. HEGO sensor
6. Throttle body
7. Additional MAP sensor
8. Coolant temperature sensor
9. Crankshaft position sensor
10. Ignition coil
11. Oil cooler adapter
12. ECM
13. Fuel control valve
14. Fuel shut-off valve
6
4
3
5
11
10
9
8
2
13
1
7
12
14
Note: Air Cleaner removed for clarity.

TP-6903 5/16a Fuel System Overview 13
1.2. Air-Fuel Mixer
Figure 1-3 Air-Fuel Mixer
The air-fuel mixer is an air-fuel metering device and is
completely self-contained. The mixer is an air valve
design, utilizing a relatively constant pressure drop to
draw fuel into the mixer from cranking to full load. The
mixer is mounted in the air stream ahead of the throttle
control device.
When the engine begins to crank it draws in air with the
air valve covering the inlet, and negative pressure
begins to build. This negative pressure signal is
communicated to the top of the air valve chamber
through vacuum ports in the air valve assembly.
The mixer is equipped with a low speed mixture
adjustment which is retained in a tamper proof housing.
The mixer has been preset at the factory and should
not be adjusted.
Important: The air-fuel mixer has been calibrated for
the engine’s emissions requirements and should never
be disassembled or rebuilt. If the air-fuel mixer is not
functioning correctly, order a replacement part. See the
engine parts catalog.
1.3. Charge Air Cooler
(KG2204T only)
Figure 1-4 Charge Air Cooler
The charge air cooler cools the compressed air/fuel
mixture before it enters the intake manifold. The cooler
intake manifold charge helps maintain emissions at the
high power level of the turbocharged engine.
1.4. Coolant Temperature Sensor
Figure 1-5 Coolant Temperature Sensor
The coolant temperature (CT) sensor is a temperature
sensitive variable resistance thermistor located in the
engine coolant passage directly underneath the air-fuel
mixer. The ECM monitors the change in resistance to
calculate engine airflow, to enrich the fuel for cold
starts, and to enable other temperature dependent
features.

14 Fuel System Overview TP-6903 5/16a
1.5. Crankshaft Position (CKP)
Sensor
Figure 1-6 Crankshaft Position Sensor
The crankshaft position (CKP) sensor measures the
rotary speed and crankshaft turning angle. The ECM
ensures the ignition timing for each cylinder depending
on the turning signal. The sensor, which consists of a
permanent magnet and coil, is installed on the timing
gear cover next to the crankshaft pulley. When the
crankshaft is turning, the gear ring passes the sensor
at different speeds and causes a change of magnet
resistance at the sensor to produce a changeable
signal.
As the engine starts to crank, the crank position sensor
(CS) sends a small AC signal to the ECM. The ECM
uses this signal for speed sensing and engine timing.
With this CS signal now active, the ECM will send a
signal to the electronic throttle (ETC) opening the
throttle for fuel flow and initiate the firing of the
electronic ignition (Cyl 1, Cyl 2). The ignition system is
a waste spark design, meaning two cylinders fire at the
same time. One cylinder will fire on its compression
stroke and the other will fire on the exhaust stroke
(waste spark).
The ECM uses the signal from the crankshaft position
sensor to determine where each piston is in relation to
its combustion cycle and to activate the ignition control
module.
1.6. Electronic Control Module
Figure 1-7 Electronic Control Module
To obtain maximum and accurate control of the air fuel
ratio, the engine is equipped with an onboard computer
or Electronic Control Module (ECM). The ECM
receives input data from sensors mounted to the
engine and fuel system and then outputs various
signals to control engine operation.
The ECM adjusts the engine speed, ignition timing, and
fuel supply in response to changes in the applied load,
surrounding air temperature, operating temperature of
the engine, and amount of oxygen present in the
exhaust.

TP-6903 5/16a Fuel System Overview 15
1.7. Fuel Control Valve
Figure 1-8 Fuel Control Valves
The fuel control valve (FCV) is an electrically controlled
engine vacuum switch. When the FCV is energized,
the valve opens and, through a vacuum line connection
to the fuel regulator, creates a vacuum on the fuel
pressure regulator. This vacuum causes the
regulator’s diaphragm to close, decreasing the fuel
delivered to the intake. The FCV signal is a modulated
signal sent by the ECM to obtain stoichiometric
combustion.
The ECM cycles FCV to provide the rich and lean
transitions required for low exhaust emissions and
peak engine performance. Based on the fuel
requirements of the engine, the ECM sends a signal to
control the amount of time that the fuel control valve is
open. Opening and closing the fuel control valve alters
the fuel pressure delivered from the regulator to the air-
fuel mixer.
When the engine starts, the engine ECM is an “open
loop” state, which means fuel delivery is based on a
fuel calibration program internal to ECM. The program
controls the fuel control valve to achieve stoichiometric
combustion.
After the oxygen sensor heats up and the engine
coolant temperature reaches a predetermined level,
the ECM calibration program transitions to a closed-
loop mode. The air/fuel delivery is based on the
oxygen sensor input and engine sensor data. The
engine ECM uses this data to regulate the fuel control
valve (FCV), which is used as a fuel trim device and is
located at the intake manifold.
1.8. Fuel Pressure Regulator
Figure 1-9 Fuel Pressure Regulator
The fuel pressure regulator ensures that the fuel enters
the system at a consistent and usable pressure. The
fuel selection on the pressure regulator can be
manually set for Natural Gas (NG) or Liquefied
Petroleum Gas (LPG).
KG2204
KG2204T

16 Fuel System Overview TP-6903 5/16a
1.9. Fuel Shut-Off Valves
Figure 1-10 Fuel Solenoid Valve
Figure 1-11 Dual-Solenoid Fuel Valve
Two solenoid valves or one dual-solenoid valve are
mounted upstream of the engine. The fuel solenoid
valves provide automatic fuel on/off control. The
engine starting battery powers the solenoid valve and
the engine starting controls open the valves when the
engine cranks or runs.
1.10.Heated Exhaust Gas Oxygen
(HEGO) Sensor
Figure 1-12 HEGO Sensor
The heated exhaust gas oxygen (HEGO) sensor
mounts to the exhaust system and is composed of a
sensor and an internal heating element.
During operation, heat from the exhaust increases the
temperature of the heating element and activates the
sensor. Once activated, the sensor measures the
oxygen content in the exhaust gas and sends a signal
to the ECM.
The ECM uses this signal to adjust the fuel flow to the
engine and to prevent the fuel flow from becoming too
rich or too lean. If the sensor signal indicates that the
fuel is too rich or too lean for an extended period of
time, the ECM will log a diagnostic code.
Important: Silicone sprays or inappropriate RTV
(room temperature vulcanization) sealers can
contaminate the HEGO sensor. Contaminated HEGO
sensors can produce false or high readings resulting in
poor fuel mixtures and severe performance problems.
Always verify that the sealer is safe to use with the
HEGO sensor before applying the sealer.

TP-6903 5/16a Fuel System Overview 17
1.11.Ignition System
Figure 1-13 Ignition Coil
The ignition system is a wasted spark system. In a
wasted spark system, spark is provided to two
cylinders simultaneously. One spark plug fires during
the compression stroke of a cylinder and creates
combustion; while the other spark plug fires during the
exhaust stroke and is wasted.
After receiving the crank signal, the ECM sends the
ignition control module a triggering signal that tells the
ignition module exactly when to make the ignition coil
spark. The ignition coil then sends a spark to each
engine cylinder through a high tension lead and the
spark plugs.
1.12.MAP and TMAP Sensors
1.12.1. Manifold Air Temperature and
Manifold Absolute Pressure
(TMAP) Sensor
Figure 1-14 TMAP Sensor
The TMAP sensor is a combination of two sensors: the
manifold absolute pressure (MAP) sensor and the
manifold air temperature (MAT) or intake air
temperature (IAT) sensor. The MAP Sensor measures
the intake manifold pressure and the MAT or IAT
sensor measures the air temperature in the intake
manifold. The ECM uses the pressure and temperature
readings in conjunction with other inputs to estimate
the airflow requirement of the engine.
The MAT sensor uses a variable resistance thermistor
to measure the air temperature and then sends a
voltage signal to the ECM. The ECM interprets the
signal voltage to indicate the temperature. If a cold start
is indicated, the ECM enriches the fuel mixture.
The MAP (Manifold Absolute Pressure) sensor portion
of the TMAP sensor is a pressure transducer
connected to the intake manifold. The MAP Sensor
uses a variable resistor to measure the absolute
pressure in the intake manifold. The ECM uses the
signal from the MAP sensor to determine the engine
load and then adjusts the fuel mixture to improve
performance and emissions.
1. TMAP sensor
2. Wire harness connector
1
2

18 Fuel System Overview TP-6903 5/16a
1.12.2. Up-stream Throttle Manifold Air
Pressure (MAP) Sensor
(KG2204T only)
The up-stream throttle manifold air pressure sensor on
the KG2204T turbocharged engine monitors the
absolute pressure (boost pressure) in the air induction
system up-stream of the throttle. Data returned by the
MAP sensor prompts the ECM to adjust the air-fuel
mixture as needed.
Figure 1-15 Manifold Absolute Pressure (MAP)
Sensor, KG2204T
1.13.Oil Pressure Sender
Figure 1-16 Oil Pressure Sender
The oil pressure sender is used to communicate a low
oil pressure condition to the ECM. Engine damage can
occur if the engine is operated with low oil pressure.
The engine oil pressure sender is designed to ensure
adequate lubrication throughout the engine. It provides
a pressure value and is monitored by the ECM. If the
pressure drops, a DTC will occur.

TP-6903 5/16a Fuel System Overview 19
1.14.Throttle Body
Figure 1-17 Throttle Body
The throttle body controls the amount of fuel that enters
the engine and is composed of a throttle blade, electric
throttle motor, and a throttle position (TP) sensor.
Engine speed control is maintained by the ECM.
Defaults programmed into the ECM software and
throttle position sensors allow the ECM to maintain
safe operating control over the engine while
maintaining speed and load control.
The electronic throttle control (ETC) device utilizes an
electric motor connected to the throttle blade. The ECM
sends an electrical signal to the motor on the electronic
throttle control to increase or decrease the angle of the
throttle blade thus increasing or decreasing the fuel
supply to the engine.
The electronic throttle control device incorporates an
internal Throttle Position (TP) sensor which provides
output signals to the ECM as to the location of the
throttle shaft and blade. The TP sensor information is
used by the ECM to correct for speed and load control.
1.15.Throttle Position (TP) Sensor
Figure 1-18 Throttle Position Sensor
The throttle position (TP) sensor is part of the throttle
body and is composed of three components: an
electronic throttle control (ETC), throttle position
sensor 1 (TP1), and throttle position sensor 2 (TP2).
TP1 and TP2 determine the throttle blade position and
send signals to ECM. The ECM receives information
from TP1 and TP2 and sends a signal to the ETC to
open or close the throttle blade. The ETC controls an
electric motor that opens and closes the throttle blade.
1. Throttle position sensor
1

20 Fuel System Overview TP-6903 5/16a
1.16.Turbocharger (KG2204T only)
Figure 1-19 Turbocharger
The turbocharger utilizes exhaust gas flowing through
the turbine to spin a compressor. The turbocharger
compressor increases boost pressure and density of
the air/fuel mixture entering the intake manifold
resulting in higher power output compared to the
naturally aspirated engine.
Figure 1-20 Turbocharger Wastegate Adjustment
A wastegate on the turbocharger bypasses exhaust
gas around the turbine when the boost pressure
reaches a maximum limit. Use Spectrum software to
check the boost pressure and adjust the wastegate
linkage, if necessary, to achieve a maximum boost
pressure of 180 kPa absolute.
1.17.Turbocharger Oil Lines
(KG2204T only)
Figure 1-21 Turbocharger oil lines
The turbocharger bearings require oil for lubrication
and cooling. Oil is fed to the turbocharger bearings
from the oil supply line on the top side of the bearing
housing and returned to the oil sump through a line
connecting the bottom side of the bearings to the
sump.
Turbochar
g
er oil line
Turbochar
g
er oil line
Wastegate
A
djustment