2007 ISUZU KB P190 air condition

Engine Management – V6 – Diagnostics Page 6C1-2–32

Checks Actions
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 the following engine mechanical fault condition. Refer to 6A1 Engine
Mechanical – V6.
• low engine compression, and
• worn valve train components.
Additional Checks
• Check the exhaust system for possible restrictions. Refer to 6F Exhaust System –
V6.
• Test for other TCM related faults that may cause the transmission to operate in
the default mode.
• Check for transmission mechanical faults that may produce similar symptoms
such as slipping clutch.
When all diagnosis and repairs are completed, check the system for correct operation.
5.11 Poor Fuel Economy
Description
As confirmed by an actual road test, the fuel economy as compared to the previous fuel consumption of the same
vehicle is noticeably lower.
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 correct tyre pressure. Refer to the Owners Manual.
• Check the recent driving conditions are the same compared to the previous when
the fuel consumption is normal. The following are list of driving conditions that
may affect fuel consumption:
− vehicle load,
− acceleration rate,
− A/C or other electrical equipment use, and
− vehicle used for towing.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–33

Checks Actions
Sensor / System
• Check the air intake system and crankcase for air leaks.
• Check the PCV System for correct operation. Refer to 6A1 Engine Mechanical –
V6.
• Check for the correct calibration of the speedometer. Refer to 8A Electrical-Body.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard
activity. Check for items that cause spark retard activity.
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
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 the items that cause an engine to run rich.
• Check for foreign material accumulation in the throttle bore, carbon build-up on
the throttle valve or on the throttle shaft.
• Check the throttle body for tampering.
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 Cooling System
• Check the engine thermostat for proper operation and correct heat range. 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.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–34

Checks Actions
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, and
• motors and generators.
• 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 7C2
Automatic Transmission – 4L60E – Electrical Diagnosis.
• Test for other TCM related faults that may cause the transmission to operate in
the default mode. Refer to 7C2 Automatic Transmission – 4L60E – Electrical
Diagnosis.
• Check for transmission mechanical faults such as slipping clutch. Refer to 7C3
Automatic Transmission – 4L60E – Hydraulic and Mechanical Diagnosis.
• Check the brake system including the parking brake for sticking or incorrect
operation.
When all diagnosis and repairs are completed, check the system for correct operation.
5.12 Rough, Unstable, Incorrect Idle or
Stalling
Description
Engine idle speed fluctuates causing the engine to run unevenly. If the engine idle speed drops too low, the engine may
stall.
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.
Sensor / System
• Check the throttle actuator control (TAC) system. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
• Check the air intake system and crankcase for air leaks. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
• Check the PCV System for correct operation. Refer to 6A1 Engine Mechanical –
V6.
• Use Tech 2 to monitor the knock sensor system for excessive spark retard
activity. Check for items that cause spark retard activity.
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s sensor should respond quickly to different throttle positions.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–35

Checks Actions
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 the items that cause an engine to run rich.
Ignition System
• Inspect for moisture or corrosion around the spark plug and 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
• Parasitic load on the engine such as the following:
• automatic transmission fault condition, or
• a belt driven accessory fault condition.
• Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –
V6.
• low compression, or
• worn valve train components.
When all diagnosis and repairs are completed, check the system for correct operation.
5.13 Surges / Chuggles
Description
W ith the accelerator pedal in a steady position, the vehicle speeds up and slows down or the engine power fluctuates.
Checks Actions
Preliminary Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this Section.
Sensor / System
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
• Test the resistance of the crankshaft position (CKP) sensor. The CKP sensor
resistance must be 700 – 1,200 Ω at all temperatures.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–36

Checks Actions
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 the items that cause an engine to run rich.
• Check for fault conditions that can cause an engine 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 ground circuit.
Additional Checks
• 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 7C2
Automatic Transmission – 4L60E – Electrical Diagnosis.
• Test the A/C clutch for correct operation. Refer to 2A Heater and Air-conditioning.
• Check the evaporative emission (EVAP) canister purge solenoid for the following
conditions: Refer to 6C1-3 Engine Management – V6 – Service Operations.
− stuck open condition, and
− charcoal contamination.
• 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.
When all diagnosis and repairs are completed, check the system for correct operation.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–47

6.7 Throttle Body Relearn
A throttle body relearn procedure is performed in one of two ways:
• Engine Control Module initiated throttle body relearn, or
• Tech 2 initiated throttle body relearn.
Engine Control Module Throttle Body Relearn
The engine control module (ECM) will automatically perform a throttle body relearn procedure if either of the following
conditions exist:
• The battery has been disconnected, or
• The ignition switch is in the ON position for greater than 29 seconds, and the following conditions are met:
− Engine speed is less than 40 rpm,
− Vehicle speed is 0 km/h,
− Engine coolant temperature is 5 – 60°C,
− Intake air temperature is 5 – 60°C,
− Accelerator pedal position sensor angle is less than 14.9%, and
− Ignition voltage is greater than 10 V.
Tech 2 Throttle Body Relearn
To perform a throttle body relearn using Tech 2, complete the following procedure:
NOTE
Tech 2 will not initiate a throttle body relearn if
the engine is running.
1 Connect Tech 2 to the data link connector (DLC) and turn the ignition on.
2 On Tech 2 select Engine / Programming / Throttle Body Relearn.
3 W hen Tech 2 displays ‘Do you really want to Reset?’, press the ‘Yes’ soft key.
4 W hen Tech 2 displays ‘Programming Completed’, and the electronic throttle control value displayed by Tech 2 is ‘11’, press the ‘Confirm’ soft key to return to the Tech 2 Programming screen.
5 The throttle body relearn is now complete.
6.8 Electronic Ignition (EI) System Diagnosis
Circuit Description
The engine control module (ECM) controls the ignition coils by pulsing the ignition control (IC) circuits, which triggers an
ignition coil and fires the spark plug. The ECM controls the sequencing and the timing of each ignition coil. The ignition
system consist of the following components:
• The six ignition coils
• The crankshaft position (CKP) sensor
• The four camshaft position (CMP) sensors
• The ECM
The ignition coils use the following circuits:
• An IC circuit
• An ignition 1 voltage circuit
• Two ground circuits

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–49

6 1 Connect the test lamp between the battery
voltage circuit of the ignition coil and to each
ground circuit of the ignition coil.
Does the test lamp illuminate at each ground circuit? —
Go to Step 8 Go to Step 10
7 1 Test the battery voltage circuit for an open or high
resistance at the splice of the affected bank of
ignition coils. Refer to 8A Electrical - Body and
Chassis for circuit testing procedures.
Did you find and correct the condition? —
Go to Step 12 Go to Step 10
8 1 Test for an intermittent and for a poor connection
at the ignition coil. Refer to 8A Electrical - Body
and Chassis for circuit testing procedures.
Did you find and correct the condition? —
Go to Step 12 Go to Step 11
9 NOTE
The battery voltage circuit is shared with
other components. Disconnecting a
component on the shared battery voltage
circuit may isolate a shorted component.
Review the electrical schematic and
diagnose the shared circuits and
components.
1 Repair a short to ground, an open or high resistance in the ignition 1 voltage circuit. Refer to
Refer to 8A Electrical - Body and Chassis for
wiring repair procedures.
2 Replace the fuse as necessary.
Did you complete the repair? —
Go to Step 12 —
10 1 Repair the open or high resistance in the ground
circuit. Refer to 8A Electrical - Body and Chassis
for wiring repair procedures.
Did you complete the repair? —
Go to Step 12 —
11 1 Replace the ignition coil. Refer to 2.15 Ignition
Coils, in 6C1-3 Engine Management – V6 –
Service Operations.
Did you complete the replacement? —
Go to Step 12 —
12 1 Connect all disconnected components.
2 Use Tech 2 to clear the DTC/s.
3 Start the engine.
4 Observe the Capture Info with Tech 2.
Do any of the misfire counters increment? —
Go to Step 2 Go to Step 13
13 1 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? — Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–61

• DTCs P0341, P0342, P0343, ran and passed:
• The engine is running.
• The ECM has learned the camshafts position.
DTC P0016
Run continuously once the following conditions are met.
• DTCs P0335, P0336, P0338, P0341, P0342 and P0343 ran and passed:
• The calculated engine oil temperature is less than 95 °C.
• The engine coolant temperature is 20 – 90 °C.
• The engine is running for greater than 5 seconds.
Conditions for Setting the DTC
DTC P0008
The ECM detects that both camshafts on bank 1 of the engine are misaligned with the crankshaft.
DTC P0009
The ECM detects that both camshafts on bank 2 of the engine are misaligned with the crankshaft.
DTC P0016
The ECM detects the following deviation in the correlation between the camshaft position and the crankshaft position for
greater than 10 minutes:
• a camshaft position is too advanced in relationship to the crankshaft, or
• a camshaft position is too retarded in relationship to the crankshaft.
Conditions for Clearing DTC
The CKP / CMP sensor correlation DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for
action taken when Type B DTCs set and conditions for clearing Type B DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the CMP system operation.
• Inspect the engine for recent engine mechanical repairs. Incorrect camshaft, camshaft actuator or timing chain
installation will trigger these DTCs.
• The engine oil condition has a major impact on the operation of the camshaft actuator.
• A low oil level may set these DTCs.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 A fault condition in any of the listed sensors will trigger these DTCs.
5 Incorrect camshaft, camshaft actuator or timing chain installation will trigger these DTCs.

BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007