2007 ISUZU KB P190 engine oil

Engine Management – V6 – General Information Page 6C1-1–36

Intermittent
An electrical signal that occurs now and then; not continuously. In electrical circuits, refers to occasional open,
short, or ground in a circuit
Light Throttle Approximately 1/4 of accelerator pedal travel (25% throttle position)
Low
A voltage less than a specific threshold. Operates the same as a ground and may, or may not, be connected
to chassis ground.
MAF Sensor Mass Air Flow Sensor. A device that provides a variable voltage to the ECM based on the amount of air flow
entering in the intake system.
Medium Throttle Approximately 1/2 of accelerator pedal travel (50% throttle position)
N.C Normally Closed. Switch contacts that are closed when they are in the normal operating position
N.O Normally Open. Switch contacts that are normally open when in the normal operating position
NOx
Nitrogen Oxide. One of the pollutants found in spark ignition engine exhaust that is formed from normal
combustion and increases in severity with combustion temperature.
O2 Sensor Oxygen Sensor. A device located in the exhaust system that provides a variable voltage to the ECM based on
the oxygen content of exhaust gas.
May also include a heating circuit to provide faster initial warm-up (HO2 sensor).
OBD On Board Diagnostic
Open Loop ECM control of the fuel control system without the use of the oxygen sensor signal.
Output Functions that are controlled by the ECM, typically these can include solenoids and relays, etc.
ECM Engine Control Module. An electronic device which controls the engine management system.
ECU Electronic Control Unit. An electronic device which controls specific system functions
PCV
Positive Crankcase Ventilation. Method of reburning crankcase fumes rather than passing them directly into
the atmosphere
PIM Powertrain Interface Module – The PIM acts as a communication translator between the ECM and other on-
board controllers that use a different serial data protocol.
PM Permanent Magnet
PWM
Pulse Width Modulated. A digital signal turned on and off for a percentage of available cycle time. A signal that
is 30% on and 70% of would be termed a 30% on PWM signal.
Quad Driver A transistor in the ECM capable of operating four separate outputs. Outputs can be either on-off or pulse width
modulated.
RAM Random Access Memory. A microprocessor can write into or read from this memory as needed. This memory
is volatile and needs a constant power supply to be retained. If the power is lost or removed, RAM data is lost.
r.p.m. Revolutions Per Minute
Serial Data
Serial data is a series of rapidly changing voltage signals pulsed from high to low. These signals are typically
transmitted through a wire often referred to as the Serial Data Circuit.
SFI Sequential Fuel Injection. Method of injecting fuel into the engine one cylinder at a time in relation to the
engines firing order.
Solenoid An electromagnetic coil which creates a magnetic field when current is applied, causing a plunger or ball to
move.
Switch Device to opens and close a circuit, thereby controlling current flow.
Tech 2
Tech 2 is a peripheral device that aids in the diagnosis and repair of electronic systems such as engine
management, transmission control etc. Tech 2 connects to the vehicle’s Data Link Connector (DLC).
TP Sensor Throttle Position sensor. A device that provides a variable voltage to the ECM based on the position of the
throttle plate.
Vacuum – manifold Vacuum sourced downstream of the throttle plate.
Vacuum – ported Vacuum sourced upstream of the throttle plate.
VSS Vehicle Speed Sensor. A permanent magnet type device that provides a digital voltage to the ECM.
WOT Wide Open Throttle – Full travel of the accelerator pedal (100% throttle position).


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Engine Management – V6 – Diagnostics Page 6C1-2–1

6C1-2 Engine Management – V6
Diagnostics
ATTENTION
Before performing any service operation or other procedure described in this Section, refer to 1.5 Warning
Caution and Notes for correct workshop practices with regard to safety and/or property damage.
1 General Information ............................................................................................................ ...................4
1.1 Diagnostic System Check ..................................................................................................................................... 4
1.2 Diagnostic Trouble Code Tables ................................................................................................. ......................... 4
1.3 Symptoms Diagnostics ......................................................................................................................................... 5
1.4 Diagnostic Trouble Codes .................................................................................................................................... 5
1.5 Warning Caution and Notes .................................................................................................................................. 6
2 GM LAN Serial Communication Circuit ............................................................................................ ....8
3 Wiring Diagrams and Connector Charts ........................................................................................... ...9
3.1 Wiring Diagrams .................................................................................................................................................... 9
3.2 ECM Connector End Views ................................................................................................................................. 12
3.2 Engine Control Connector End Views ............................................................................................. .................. 16
4 Diagnostics Starting Point...................................................................................................................18
4.1 Basic Requirements ............................................................................................................................................ 18
4.2 Diagnostic Precautions ......................................................................................................... .............................. 18
4.3 Preliminary Checks.............................................................................................................................................. 19
4.4 Diagnostic System Check ........................................................................................................ ........................... 20
5 Symptoms Diagnostics ........................................................................................................................22
5.1 Symptoms Diagnosis Table ....................................................................................................... ......................... 22
5.2 Intermittent Fault Conditions .............................................................................................................................. 22
5.3 Backfire................................................................................................................................................................. 24
5.4 Cranks But Does Not Run ........................................................................................................ ........................... 26
5.5 Cuts Out, Misses.................................................................................................................................................. 27
5.6 Detonation / Spark Knock ....................................................................................................... ............................ 28
5.7 Dieseling, Run-on ................................................................................................................................................ 28
5.8 Hard Start ............................................................................................................................................................. 29
5.9 Hesitation, Sag and Stumble .................................................................................................... .......................... 30
5.10 Lack of Power, Sluggishness or Sponginess ...................................................................................... ............. 31
5.11 Poor Fuel Economy ............................................................................................................................................. 32
5.12 Rough, Unstable, Incorrect Idle or Stalling .................................................................................... ................... 34
5.13 Surges / Chuggles ............................................................................................................................................... 35
6 Functional Checks................................................................................................................................37
6.1 General Information ............................................................................................................ ................................. 37
6.2 Fuel Injector Coil Test ......................................................................................................................................... 37
6.3 Fuel Injector Balance Test ..................................................................................................... ............................. 42
6.4 Fuel Injector Leak Down Test ................................................................................................... .......................... 44
6.5 Alcohol / Contaminants in Fuel Diagnosis ....................................................................................... ................. 46
6.6 Crankshaft Position (CKP) System Variation Learn Procedure..................................................................... .. 46
6.7 Throttle Body Relearn.......................................................................................................................................... 47

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Engine Management – V6 – Diagnostics Page 6C1-2–13

E-60–27 Not Used
E-60–28 Not Used
E-60–29 Not
Used
E-60–30 Not Used
E-60–31 Y ETC_NEG TAC Motor Control (Negative)
E-60–32 L O2_HTR_2 B2S1 HO2S Heater Low Control (Bank 2 Sensor 1)
E-60–33 L KNK1 Knock Sensor 1 Signal (Bank 1)
E-60–34 V/W HI_SIG_2 B2S1 HO2S High Signal (Bank 2 Sensor 1)
E-60–35 V/W PMP_1 B1S1 HO2S Pump Current (Bank 1 Sensor 1)
E-60–36 Not Used
E-60–37 BR OIL_LVL Oil Level Switch Signal
E-60–38 G/W OIL_TMP Oil Temperature Sensor Signal
E-60–39 BR/T 5VGD3 Low Reference – Ground 3
E-60–40 GR/B OIL_PRESS Oil Pressure Sensor Signal
E-60–41 DG EST5 EST 5 Control
E-60–42 V EST1 EST 1 Control
E-60–43 O CHRG_1 Generator Turn On Signal (‘L’ Terminal)
E-60–44 Not Used
E-60–45 LB INJR_4 Fuel Injector 4 Control
E-60–46 P/L INJR_3 Fuel Injector 3 Control
E-60–47 BR/W INJR_5 Fuel Injector 5 Control
E-60–48 G/W CNPUR EVAP Canister Purge Solenoid Control
E-60–49 GR/B RET5 CKP Sensor Shield Return
E-60–50 LB KNK2 Knock Sensor 2 Signal (Bank 2)
E-60–51 W PMP_2 B2S1 HO2S Pump Current (Bank 2 Sensor 1)
E-60–52 BR/G O2_RTN_1 B1S1 HO2S Low Signal (Bank 1 Sensor 1)
E-60–53 Not Used
E-60–54 GR 5VDC2 5 Volt Reference – 2
E-60–55 G TPS-1 TP Sensor 1 Signal
E-60–56 LG MAP MAP Sensor Signal
E-60–57 GR 5VDC5 5 Volt Reference – 5
E-60–58 LB EST3 EST 3 Control
E-60–59 B 5VGD6 CKP Sensor Low – Ground 6
E-60–60 Not Used
E-60–61 Not Used
E-60–62 LG INJR_2 Fuel Injector 2 Control
E-60–63 BR/L INJR_1 Fuel Injector 1 Control
E-60–64 Y/B INJR_6 Fuel Injector 6 Control

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Engine Management – V6 – Diagnostics Page 6C1-2–15

C-56–28 Not Used
C-56–29 V HI_SIG_3 B1S2 O2 Sensor High Signal (Bank 1 Sensor 2)
C-56–30 Not Used
C-56–31 R/W CRANK_REQ Crank Voltage
C-56–32 B PRKNEU Park/Neutral Switch Signal
C-56–33 Not Used
C-56–34 Not Used
C-56–35 Y START_RLY Starter Relay Coil Control
C-56–36 BR/R BATT + Battery Positive Voltage
C-56–37 Not Used
C-56–38 PU SDI Data Link Connector (DLC) Serial Data
C-56–39 R 5VDC1 5 Volt Reference 1
C-56–40 BR 5VGD5 Low Reference – Ground 5
C-56–41 P RTN_4 B2S2 O2 Sensor Low Signal (Bank 2 Sensor 2)
C-56–42 Y/R FUEL_LVL1 Fuel Level Sensor Signal
C-56–43 Y MAF MAF Sensor Signal
C-56–44 Y PED_POS_2 APP Sensor 2 Signal
C-56–45 Not Used
C-56–46 GR/R CRU_ETC_TCC Brake Switch (S220 – ‘C’) Cruise Cancel Signal
C-56–47 Not Used
C-56–48 Not Used
C-56–49 GR/R AC_CLU A/C Compressor Clutch Relay Control
C-56–50 BR/Y MIL Malfunction indicator Lamp
C-56–51 Not Used
C-56–52 Not Used
C-56–53 BR CRCTL_CLU_SW Clutch Switch (S42) Cruise Cancel Signal
C-56–54 Not Used
C-56–55 R/G CAN_LO_2 GMLAN Serial Data Bus – Low
C-56–56 BR/Y 5VDC3 5 Volt Reference 3
C-56–57 BR/R RTN_3 B1S2 O2 Sensor Low Signal (Bank 1 Sensor 2)
C-56–58 R/Y ACC Accessory Voltage
C-56–59 Not Used
C-56–60 L PED_POS_1 APP Sensor 1 Signal
C-56–61 V HI_SIG_4 B2S2 O2 Sensor High Signal (Bank 2 Sensor 2)
C-56–62 Not Used
C-56–63 Not Used
C-56–64 Not Used

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Engine Management – V6 – Diagnostics Page 6C1-2–20

• Ensure the resistance between the ECM housing and the battery negative cable is less than 0.5 Ω.
• Check the ECM bracket fasteners for correct torque value.
• Check all engine management related components for correct installation.
• Inspect the vacuum hoses for splits, kinks, oil contamination and proper connections, refer to the vehicle emission
control information label. Check the hoses thoroughly for any type of leak or restriction.
• Inspect the air intake ducts for being collapsed, split or for having damaged areas.
• Inspect for air leaks at the throttle body mounting area, mass air flow (MAF) sensor, intake manifold and intake
manifold sealing surfaces.
• Check for wiring harness routing that may be positioned too close to a high voltage or high current device such as
the following:
− Secondary ignition components, and
− Motors and generators.
NOTE
High voltage or high current devices may induce
electrical noise on a circuit, which can interfere
with normal circuit operation.
4.4 Diagnostic System Check
Description
The engine management diagnostic procedure is organised in a logical structure that begins with the Diagnostic System
Check. The Diagnostic System Check directs the diagnostic procedure to the logical steps necessary to diagnose an
engine driveability fault condition.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
6 Tests the integrity of the GM LAN serial data communication circuit. A PIM DTC sets if the PIM detects a fault condition in the communication circuit. A fault condition on the serial data communication circuit may trigger
multiple DTCs on other sensors and components.
Step Action Yes No
1 Have you read the basic requirements?
Go to Step 2 Refer to
4.1 Basic
Requirements
2 Have you read the diagnostic precautions?
Go to Step 3 Refer to
4.2 Diagnostic Precautions
3 Have you performed the preliminary checks?
Go to Step 4 Refer to
4.3 Preliminary Checks
4 Using Tech 2, attempt to communicate with the PIM.
Does the PIM fail to communicate? Refer to 6E1
Powertrain Interface Module – V6 Go to Step 5
5 Does DTC B3902, C0550, U2100, U2105, U2106, P0633, or P1611
also set in the PIM? Refer to 6E1
Powertrain Interface Module – V6 Go to Step 6
6 Using Tech 2, view and record DTCs set at the ECM and TCM.
Does Tech 2 display any DTC? Go to Step 7 Refer to
5.1 Symptoms
Diagnosis Table

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Engine Management – V6 – Diagnostics Page 6C1-2–25

Checks Actions
Fuel System
• Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6 – V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check the items that can cause an engine to run lean.
• Check the items that cause an engine to run rich.
Ignition System
• Check for an intermittent ignition circuit malfunction.
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Cooling System Check the engine for over-heating. Refer to 6B1 Engine Cooling – V6.
Engine Mechanical Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical – V6.
• low compression, and
• worn valve train components.
Additional Checks
• Check the exhaust system for possible restrictions. Refer to 6F Exhaust System –
V6.
• Electromagnetic interference (EMI) on the crankshaft position (CKP) sensor can
cause an engine misfire condition.
Using Tech 2, monitor the engine speed parameter. A sudden increase in the engine speed parameters without moving the throttle position indicates that an
Electromagnetic Interference fault may be present.
W iring harness routing which may be positioned very close to a high voltage or high current device such as the following may induce EMI:
• secondary ignition components, or
• motors and generators.
Dirty starter motor commutator or brushes can mask the crankshaft position sensor signal.
• Check the torque converter clutch (TCC) operation. A TCC that applies too soon
can cause engine detonation, which will trigger spark retard activity. Refer to 7C1
Automatic Transmission – 4L60E – General Information.
When all diagnosis and repairs are completed, check the system for correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–26

5.4 Cranks But Does Not Run
Definition
The engine cranks normally but does not start.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the immobiliser system for correct operation. Refer to 11A Immobiliser.
Sensor / System
• Check the engine coolant temperature (ECT) sensor for an incorrect value.
Compare the engine coolant temperature against the intake air temperature (IAT)
on a cold engine. The ECT and IAT sensor values should be within ± 3°C of each
other. Refer to 6C1-3 Engine Management – V6 – Service Operations for details
of the Temperature vs. Resistance Table.
• Check the mass air flow (MAF) sensor installation. Incorrect installation of the
MAF sensor may cause hard start condition. Refer to 6C1-3 Engine Management
– V6 – Service Operations.
• Check for a dirty starter motor commutator or brushes that can mask the
crankshaft position sensor signal.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure,
• contaminated fuel, and
• incorrect fuel pump relay operation.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
Ignition System • Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
Check for loose ignition coil ground circuit.
Engine Mechanical • Check for excessive oil in combustion chamber. Refer to 6A1 Engine Mechanical
– V6.
• Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –
V6.
• low compression, and
• worn valve train components.
When all diagnosis and repairs are completed, check the system for correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–27

5.5 Cuts Out, Misses
Description
Steady pulsation or jerking that is usually more severe as the engine load increases. This condition is not normally felt
greater than 1500 rpm or 48 km/h. The exhaust has a steady spitting sound at idle or low speed.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
• Check for intake manifold vacuum leak.
Sensor / System
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard
activity. Check for items that cause spark retard activity. Refer to 7.19 DTC
P0327, P0328, P0332 or P0333.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check for fault conditions that cause an engine to run rich or to run lean.
Ignition System
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil grounds.
Engine Mechanical Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –V6.
• low compression, and
• worn valve train components.

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