2007 ISUZU KB P190 DTC CHECK

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–66
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 3-2 downshifts if the vehicle speed is greater than 40 km/h.
• 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 P0752 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.
Diagnostic Aids
• If you clear DTC P0752, and then cannot reset DTC P0752, the following conditions may exist:
• Fluid contamination,
• Blocked fluid circuits, or
• Restricted fluid circuits.
• Refer to 5.6 Shift Solenoid Valve State and Gear Ratio.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.
3 Checks the mechanical components that cause the DTC and their state.
DTC P0752 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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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–67
Step Action Yes No
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 Drive the vehicle in D4 range under the following conditions:
• Accelerate the vehicle, and
• Ensure the TCM commands 1st, 2nd, 3rd and 4th gears.
Did you detect a 1-1-4-4 shift pattern? Go to Step 3 Refer to Diagnostic
Aids within this Section
3 Inspect the shift solenoid/hydraulic circuit for the following conditions:
• An internal malfunction.
• Damaged seals on the shift solenoid valve. Perform the shift
solenoid leak test, refer to 7C3 Automatic Transmission – 4L60E
– Hydraulic and Mechanical Diagnosis.
Did you find and correct the condition? Go to Step 4 —
4 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 Drive the vehicle in D4 range under the following conditions, only if traffic and road conditions permit:
• Hold the throttle at 20%, and
• Accelerate to 88 km/h.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0752 set? Go to Step 2 Go to Step 5
5 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.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–69
• The TCM cancels the DTC default actions when the ignition is off long enough to power down the TCM.
Diagnostic Aids
•
If you clear DTC P0756, and then cannot reset DTC P0756, the following conditions may exist:
• Fluid contamination,
• Blocked fluid circuits, or
• Restricted fluid circuits.
• Refer to 5.6 Shift Solenoid Valve State and Gear Ratio.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.
3 Checks the mechanical components that cause the DTC and their state.
DTC P0756 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 Drive the vehicle in D4 range under the following conditions:
• Accelerate the vehicle, and
• Ensure the TCM commands 1st, 2nd, 3rd and 4th gears.
Did you detect a 4-3-3-4 shift pattern? Go to Step 3 Refer to Diagnostic
Aids within this
Section

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–70
Step Action Yes No
3 1 Inspect the shift solenoid/hydraulic circuit for the following
conditions:
• Debris or chips in the AFL oil passage.
• Debris or chips restricting oil flow in passage #29 of the
case or through the spacer plate gasket into the valve
body.
• A cracked 2-3 shift solenoid.
• A 2-3 shift valve which is stuck or hung up in the valve
body bore.
• A 2-3 shuttle valve which is stuck or hung up in its bore.
• Damaged seals on the shift solenoid valves. Perform the
shift solenoid leak test, refer to 7C3 Automatic
Transmission – 4L60E – Hydraulic and Mechanical
Diagnosis.
2 Clean and inspect the related valves, bores and the valve body for debris or contamination.
Did you find and correct the condition? Go to Step 4 —
4 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 Drive the vehicle in D4 range under the following conditions, only if traffic and road conditions permit:
• Hold the throttle at 40%, and
• Accelerate to 64 km/h.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0756 set? Go to Step 2 Go to Step 5
5 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.
4.23 DTC P0757 – 2-3 Shift Solenoid Valve
Performance – No Third or Fourth Gear
DTC Description
This diagnostic procedure supports DTC P0757 2-3 Shift Solenoid (SS) Valve Performance – No Third or Fourth Gear.
Circuit Description
The 2-3 shift solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The 2-3 SS valve is a normally-
open exhaust valve that is used with the 1-2 SS valve to allow four different shifting combinations.
When the transmission control module (TCM) detects a 1-2-2-1 shift pattern, then DTC P0757 sets. DTC P0757 is a
type A 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 7C2–71
Conditions for Running the DTC
• No DTCs P0120, P0722, P0723, P0742, P0973, P0974, P0976, P0977 or P1815.
• The engine torque is 108 – 882 Nm.
• The engine run time is greater than 5 seconds.
• The transmission fluid temperature is 20 – 130°C.
• The throttle position is greater than 10 percent.
• The output shaft speed is greater than 150 r.p.m.
Conditions for Setting the DTC
The TCM commands 3rd gear and the resulting gear ratio is a 1.44:1 – 1.52:1, 1st gear, for 2.25 seconds.
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 4th gear.
• 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 P0757 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.
Diagnostic Aids
• If you clear DTC P0757, and then cannot reset DTC P0757, the following conditions may exist:
• Fluid contamination,
• Blocked fluid circuits, or
• Restricted fluid circuits.
• Refer to 5.6 Shift Solenoid Valve State and Gear Ratio.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
2 This step tests the TCM commanded all shifts, all shift solenoid valves responded correctly, and if all the shifts did not occur.
3 Checks the mechanical components that cause the DTC and their state.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–72
DTC P0757 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 Drive the vehicle in D4 range under the following conditions:
• Accelerate the vehicle, and
• Ensure the TCM commands 1st, 2nd, 3rd and 4th gears.
Did you detect a 1-2-2-1 shift pattern? Go to Step 3 Refer to Diagnostic
Aids within this
Section
3 Inspect the shift solenoid/hydraulic circuit for the following conditions:
• An internal malfunction
• Damaged seals on the shift solenoid valve. Perform the shift
solenoid leak test, refer to 7C3 Automatic Transmission – 4L60E
– Hydraulic and Mechanical Diagnosis.
Did you find and correct the condition? Go to Step 4
—
4 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 Drive the vehicle in D4 range under the following conditions, only if traffic and road conditions permit:
• Hold the throttle at 15%, and
• Accelerate to 80 km/h.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P0757 set? Go to Step 2 Go to Step 5

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–73
Step Action Yes No
5 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.
4.24 DTC P0787 – 3-2 Shift Solenoid Control
Circuit Low Voltage
DTC Description
This diagnostic procedure supports the following DTC:
DTC P0787 3-2 Shift Solenoid (SS) Control Circuit Low Voltage.
Circuit Description
The 3-2 shift solenoid (SS) valve is a normally-closed, 3-port, on/off device that controls the 3-2 downshift. The solenoid
attaches to the control valve body within the transmission. The solenoid receives ignition voltage through the ignition
circuit. The transmission control module (TCM) controls the solenoid by providing a ground path on the 3-2 shift solenoid
valve control circuit. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The TCM varies the timing
between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and the throttle position.
When the TCM detects a continuous open or short to ground in the 3-2 SS valve circuit, then DTC P0787 sets.
DTC P0787 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 10 – 18 V.
• The engine speed is greater than 450 r.p.m. for 5 seconds.
• Vehicle speed is less than 200 km/h.
Conditions for Setting the DTC
The TCM commands the solenoid off and the voltage feedback remains low, 0 V.
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 commands 3rd gear.
• 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 P0787 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.

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ISUZU KB P190 2007

Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–74
• 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:
4 Checks the ability of the TCM to control the solenoid.
5 Checks for supply voltage to the 3-2 SS valve.
6 Checks the ability of the TCM and wiring to control the ground circuit.
8 Checks the resistance of the control valve body wiring harness and the 3-2 SS valve.
9 Checks if the 3-2 SS or control valve body wiring harness is shorted to the transmission housing.
13 Checks if the control valve body wiring harness is shorted to ground.
14 Checks if any of the other solenoids in the transmission are shorted to ground.
DTC P0787 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.
Are any of the following DTCs also set?
• P0961
• P0973
• P0976
• P2764
• P2769. Go to Step 3 Go to Step 4
3 Inspect fuse C-8 and check if it is blown, refer to 8A Electrical-Body
and Chassis.
Is the fuse blown? Replace the fuse
Go to Step 12 Go to Step 5

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ISUZU KB P190 2007