2007 ISUZU KB P190 service

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–55
Step Action Yes No
6 1 Disconnect connector C-96 from the TCM.
2 Test circuits speed sensor circuits (between C-96 pin 16 and E-44 pin 2; C-96 pin 41 and E-44 pin 1) for the following
conditions:
• Short to ground,
• Short to battery,
• Open circuit, and
• Short together.
Did you find and correct the condition? Go to Step 9 Go to Step 8
7 Replace the vehicle speed sensor, refer to 7C4 Automatic
Transmission – 4L60E – On-vehicle Service.
Did you complete the replacement? Go to Step 9 —
8 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Service.
Did you complete the replacement? Go to Step 9 —
9 Perform the following procedure to verify the repair:
1 On Tech 2 select: Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
2 Follow the instructions on Tech 2 and clear any DTCs.
3 On Tech 2 select: Data Display / Transmission Data.
4 Operate the vehicle ensuring the transmission output speed drop is less than 500 r.p.m. for 2 seconds and output speed is
greater than 500 r.p.m.
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0723 set? Go to Step 2 Go to Step 10
10 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Does Tech 2 display any DTCs you have not diagnosed? Refer to
4.8 Diagnostic Trouble Code List System OK
When all diagnosis and repairs are completed, check the system for correct operation.
4.17 DTC P0724 – Brake Switch Circuit Low
Input (Stuck Off)
DTC Description
This diagnostic procedure supports DTC P0724 Brake Switch Circuit Low Voltage.
Circuit Description
The transmission control module receives a direct input from the stop lamp switch assembly. When the brake pedal is
pressed, 12 V is supplied to the TCM through connector C-96 pin 42.
When the TCM detects an open or short to ground on the stop lamp signal circuit during stopping then DTC P0724 sets.
DTC P0724 is a type C DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–56
Conditions for Running the DTC
• No DTCs P0719, P0722 or P0723.
• The vehicle speed is greater than 40 km/h for 7 seconds, then 8 – 40 km/h for 5 seconds, then less than 8 km/h.
• Continuously eight times once the previous criteria have been met.
Conditions for Setting the DTC
The TCM detects an open or short to ground on the stop lamp switch signal circuit when the circuit should be high,
battery voltage.
Action Taken When the DTC Sets
• The TCM does not request the engine control module (ECM) to illuminate the MIL.
• The TCM records the operating conditions when the conditions for setting the DTC are met. The TCM records this
information as a Failure Record.
• The TCM stores DTC P0724 in TCM history.
Conditions for Clearing the DTC
•
The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• Tech 2 can clear the DTC.
Diagnostic Aids

• Verify the brake pedal position sensor is
adjusted properly, refer to 8B Cruise
Control.
• Test drive the vehicle if a switch or circuit
condition cannot be located. An
intermittent condition may be duplicated
during a test drive.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Checks if the stop lamp switch is serviceable.
4 Checks if there is a stop lamp switch signal to the TCM.
DTC P0724 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check
2 1 Connect Tech 2 to the DLC.
2 On Tech 2 select: Engine / V6 Engine / Data Display / Cruise / Traction Data.
3 Turn on the ignition, with the engine off.
4 Press the brake pedal.
Does the Stop Lamp Pedal Switch parameter indicate
Active? Check for an
intermittent fault in the circuit, refer to
8A Electrical-Body and Chassis Go to Step 3

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–57
Step Action Yes No
3 Test the stop lamp switch assembly, refer to 8B Cruise Control.
Is the stop lamp switch assembly serviceable? Go to Step 4 Replace the stop
lamp switch assembly
4 1 Disconnect connector C-96 from the TCM.
2 Using a multimeter set to measure voltage, probe between harness connector C-96 pin 42 and a known ground.
3 Press the brake pedal.
Does the multimeter display battery voltage? Go to Step 5 Repair or replace
affected circuit
Go to Step 6
5 Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 6 —
6 Perform the following procedure to verify the repair:
1 On Tech 2 select: Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
2 Follow the instructions on Tech 2 and clear any DTCs.
3 Operate the vehicle under the following conditions:
• Turn on the ignition, with the engine off for at least
2 seconds.
• Start the vehicle and idle for 5 seconds.
• Drive in D4 from 0 – 60 km/h then brake, eight times in one
ignition cycle.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0724 set? Go to Step 2 Go to Step 7
7 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Does Tech 2 display any DTCs you have not diagnosed? Refer to
4.8 Diagnostic Trouble Code List System OK
When all diagnosis and repairs are completed, check the
system for correct operation.
4.18 DTC P0741 – Torque Converter Clutch
System – Stuck Off
DTC Description
This diagnostic procedure supports DTC P0741 Torque Converter Clutch (TCC) System - Stuck Off.
Circuit Description
The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used with the torque converter
clutch pulse width modulation (TCC PWM) solenoid valve to control fluid acting on the converter clutch apply valve. The
TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. W hen grounded by the
transmission control module (TCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes
converter signal oil pressure to increase and move the converter clutch apply valve against spring force and into the
apply position. In this position, release fluid is open to an exhaust port and converter feed fluid fills the apply fluid circu it.
The converter feed fluid applies the TCC. When the TCM no longer provides a ground path, the TCC solenoid valve de-
energizes and apply fluid exhausts, releasing the TCC.
When the TCM detects high torque converter slip when the TCC is commanded off, then DTC P0741 sets. DTC P0741 is
a type B DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–78
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Checks for a short to voltage in the 3-2 SS signal circuit.
3 Checks for the serviceability of the 3-2 SS.
DTC P0788 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check
2 1 Connect Tech 2 to the DLC.
2 Turn on the ignition, with the engine off.
NOTE
Before clearing the DTC, use the Tech 2 Freeze
Frame/Failure Record to record the transmission
parameters at the time the DTC set. Using Tech 2 to clear
the DTC(s) erases the Freeze Frame/Failure Record
records from the TCM.
3 On Tech 2 select: Transmission / Automatic Transmission / Diagnostic
Trouble Codes / Freeze Frame.
4 Select the relevant DTC and note the parameters at the time of the DTC setting.
5 On Tech 2 select:
Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
6 Follow the instructions on Tech 2 and clear the DTCs.
7 Turn off the ignition.
8 Disconnect connector E-95 from the transmission.
NOTE
Additional DTCs may set
9 Install Tool No. J 44152 Jumper Harness (20 pins) on to the harness connector E-95.
10 Turn on the ignition, with the engine off.
11 Using a test lamp and Tool No. J 35616-C, probe between connector E-95 pin 11 and a known ground.
Does the test lamp illuminate? Go to Step 5 Go to Step 3
3 1 Install Tool No. J 44152 to the transmission connector E-95.
2 Using a multimeter set to measure resistance, probe across transmission connector E-95 pins 10 and 11.
Does the multimeter display less than 20 Ω? Go to Step 4 Go to Step 6

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–87
• The TCM records the operating conditions when the conditions for setting the DTC are met. The TCM records this
information as a Failure Record.
• The TCM freezes transmission adaptive functions.
• The TCM commands maximum line pressure.
• The TCM stores DTC P0961 in TCM history.
Conditions for Clearing the DTC
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• Tech 2 can clear the DTC.
Diagnostic Aids
DTC P0961 may set under low voltage conditions caused by high electrical system demands.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Checks the ability of the TCM to control the solenoid.
3 Checks the resistance of the control valve body wiring harness and the PC solenoid.
5 Checks the serviceability of the PC solenoid circuits contained in the control valve body wiring harness.
6-8 Checks the serviceability the power and signal circuits between the TCM and the transmission.
DTC P0961 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic
System Check

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–94
attaches to the control valve body within the transmission. The 1-2 SS valve receives ignition voltage through the ignition
voltage circuit. The transmission control module (TCM) controls the solenoid by providing the ground path on the 1-2 SS
valve control circuit.
When the TCM detects a continuous short to voltage in the 1-2 shift solenoid valve control circuit, then DTC P0974 sets.
DTC P0974 is a type A DTC.
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
• The system voltage is 8 – 18 V.
• The engine speed is 500 r.p.m. for 5 seconds.
Conditions for Setting the DTC
DTC P0974 sets if the TCM commands the solenoid on and the voltage feedback remains high, battery voltage.
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the Conditions for
Setting the DTC are met.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• The TCM inhibits TCC engagement.
• At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.
• The TCM stores DTC P0974 in TCM history during the second consecutive trip in which the conditions for setting
the DTC are met.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Checks the ability of the TCM to command the 1-2 SS valve.
3 Checks for a short to voltage in the 1-2 SS signal circuit.
4 Checks the serviceability of the 1-2 SS and the control valve body wiring harness.
DTC P0974 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–101
Refer to 2 W iring Diagrams and Connector Chart to aid in diagnosis.
Conditions for Running the DTC
•
The system voltage is 8 – 18 V.
• The engine speed is 500 r.p.m. for 5 seconds.
Conditions for Setting the DTC
DTC P0977 sets if the TCM commands the solenoid on and the voltage feedback remains high, battery voltage.
Action Taken When the DTC Sets
• The TCM requests the ECM to illuminate the MIL during the second consecutive trip in which the conditions for
setting the DTC are met.
• The TCM commands maximum line pressure.
• The TCM freezes transmission adaptive functions.
• The TCM inhibits TCC engagement.
• At the time of the first failure, the TCM records the operating conditions when the conditions for setting the DTC are
met. The TCM stores this information as a Failure Record.
• At the time of the second failure, the ECM records the operating conditions when the conditions for setting the DTC
are met. The ECM stores this information as a Freeze Frame.
• The TCM stores DTC P0977 in TCM history during the second consecutive trip in which the conditions for setting
the DTC are met.
Conditions for Clearing the DTC
• The ECM turns off the MIL after the fourth consecutive drive trip in which the TCM does not send a MIL illumination
request.
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Checks for a short to voltage in the 2-3 SS signal circuit.
4 Checks the serviceability of the 2-3 SS.
DTC P0977 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check

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Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–109
• Tech 2 can clear the DTC.
• The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission
related diagnostic fault occurring.
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 Checks for a short to voltage in the TCC PW M solenoid valve signal circuit.
3 Checks the serviceability of the TCC PWM solenoid valve.
DTC P2763 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.7 Diagnostic System Check
2 1 Connect Tech 2 to the DLC.
2 Turn on the ignition, with the engine off.
NOTE
Before clearing the DTC, use the Tech 2 Freeze
Frame/Failure Record to record the transmission
parameters at the time the DTC set. Using Tech 2 to clear
the DTC(s) erases the Freeze Frame/Failure Record
records from the TCM.
3 On Tech 2 select: Transmission / Automatic Transmission / Diagnostic
Trouble Codes / Freeze Frame.
4 Select the relevant DTC and note the parameters at the time of the DTC setting.
5 On Tech 2 select:
Diagnostic Trouble Codes / Clear Engine & Transmission
DTCs.
6 Follow the instructions on Tech 2 and clear the DTCs.
7 On Tech 2 select: Transmission / Automatic Transmission / Miscellaneous
Tests / TCC PWM Solenoid.
8 With Tech 2 command the TCC PWM solenoid ON and OFF
three times.
9 On Tech 2 select: Data Display / TCC Data.
Does Tech 2 display the TCC Duty Cycle Circuit as Okay ? Check for an
intermittent fault in the circuit, refer to
8A Electrical-Body
and Chassis Go to Step 3

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ISUZU KB P190 2007