Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–77
Step Action Yes No
When all diagnosis and repairs are completed, check the system for correct operation.
4.25 DTC P0788 – 3-2 Shift Solenoid Control
Circuit High Voltage
DTC Description
This diagnostic procedure supports DTC P0788 3-2 Shift Solenoid (SS) Control Circuit High 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 1
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 short to voltage in the 3-2 shift solenoid valve control circuit, then DTC P0788 sets.
DTC P0788 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 450 r.p.m. for 5 seconds.
• The engine is not in fuel cut off.
Conditions for Setting the DTC
DTC P0788 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 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 P0788 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.
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ISUZU KB P190 2007
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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ISUZU KB P190 2007
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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ISUZU KB P190 2007
Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–107
Step Action Yes No
6 1 Disconnect connector C-96 from the TCM.
2 Using a multimeter set to measure resistance, probe across the following pins:
• connector E-95 pins 5 and 13,
• connector E-95 pins 5 and 12, and
• connector E-95 pins 12 and 13.
Does the multimeter display continuity in any of the tests? Go to Step 9 Go to Step 10
7 Test the circuit (A/B/C) that displayed Closed on Tech 2, for a short to
ground between connector E-95 and C-96.
Did you find and correct the condition? Go to Step 12 Go to Step 11
8 Test the signal circuits of the TFP manual valve position switch that
did not indicate battery voltage for an open circuit between connectors
E-95 and C-96.
Did you find and correct the condition? Go to Step 12 Go to Step 11
9 Test the affected signal circuits of the TFP manual valve position
switch for a shorted together condition between E-95 and C-96.
Did you find and correct the condition? Go to Step 12 Go to Step 11
10 Test the TFP circuits for an open circuit or shorted condition between
connector E-95 and the TFP manual valve position switch.
Did you find a condition? Replace the control
valve body wiring harness, refer to
7C4 Automatic
Transmission –
4L60E – On-vehicle Servicing.
Go to Step 12 Replace the TFP
manual valve
position switch, refer
to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.
Go to Step 12
11 Replace the TCM refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.
Did you complete the replacement? Go to Step 12 —
12 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 until the TCC locks for 10 seconds.
• Continue to run the engine for at least 60 seconds from
start-up.
4 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P1810 set? Go to Step 2 Go to Step 13
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ISUZU KB P190 2007
Automatic Transmission – 4L60E – Electrical Diagnosis Page 7C2–108
Step Action Yes No
13 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.
4.33 DTC P2763 – Torque Converter Clutch
Pressure Control Solenoid Control
Circuit High Voltage
DTC Description
This diagnostic procedure supports DTC P2763 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control
Circuit High Voltage.
Circuit Description
The torque converter clutch pulse width modulation (TCC PW M) solenoid valve controls the fluid acting on the converter
clutch valve. The converter clutch valve controls the TCC application and release. The solenoid attaches to the control
valve body within the transmission. The solenoid receives voltage through ignition voltage circuit. The transmission
control module (TCM) controls the solenoid by providing a ground path on the TCC PW M solenoid valve control circuit.
Current flows through the solenoid coil according to the duty cycle, percentage of on and off time. The TCC PWM
solenoid valve provides a smooth engagement of the TCC by operating during a duty cycle percent of on time.
When the TCM detects a continuous short to voltage in the TCC PW M solenoid valve control circuit, then DTC P2763
sets. DTC P2763 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 P2763 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.
• The TCM inhibits 4th gear if in hot mode.
• 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 P2763 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 7C2–119
16 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: Miscellaneous Tests / TCC Solenoid.
4 Drive the vehicle in D4. With Tech 2 command the TCC solenoid valve On for 5 seconds and Off for 5 seconds
5 On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.
Has DTC P2769 set? Go to Step 2 Go to Step 17
17 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.
4.36 DTC P2770 – Torque Converter Clutch
Enable Solenoid Control Circuit High
Voltage
DTC Description
This diagnostic procedure supports DTC P2770 Torque Converter Clutch (TCC) Enable Solenoid Control Circuit High
Voltage.
Circuit Description
The torque converter clutch (TCC) solenoid valve is an electrical device that is used with the torque converter clutch
pulse width modulation (TCC PWM) solenoid valve to control TCC apply and release. The TCC solenoid valve attaches
to the transmission case assembly extending into the pump cover. The TCC solenoid valve receives voltage through
ignition voltage circuit. The transmission control module (TCM) controls the solenoid by providing the ground path on the
TCC solenoid valve control circuit. The TCM monitors the throttle position (TP) voltage, the vehicle speed and other
inputs to determine when to energize the TCC solenoid valve.
NOTE
The TCC solenoid valve is part of the control
valve body wiring harness. To replace the
solenoid valve, the control valve body harness
must be replaced.
W hen the TCM detects a continuous short to voltage in the TCC solenoid valve control circuit, then DTC P2770 sets.
DTC P2770 is a type B 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 P2770 sets if the TCM commands the solenoid on and the voltage feedback remains high, battery voltage.
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Automatic Transmission – 4L60E – On-vehicle Servicing Page 7C4–39
10 Reinstall the plate (2) supporting the spacer plate and
tighten the three attaching bolts (1) to the correct
torque specification.
Spacer plate support plate attaching
bolt torque specification ..................................... 12.0 Nm
11 Reinstall the control valve body, refer to 3.14 Control Valve Body.
12 Reinstall the Oil pan and filter and fill the transmission with the recommended automatic transmission fluid,
refer to 3.1 Fluid Change and Filter Replacement.
13 Lower vehicle to the ground.
14 Road test until the transmission has reached operating temperature. Re-check the fluid level and for any fluid
leaks from the oil pan area, refer to 2.1 Transmission
Fluid.
Figure 7C4 – 55
3.16 Filler Tube and Breather Hose
Remove
NOTE
The breather hose and/or vent pipe can be
removed independently from the filler tube as
described in step 7.
Disconnection of the battery affects certain
vehicle electronic systems. Refer to 6D1-3
Battery, before disconnecting the battery.
1 Disconnect the battery ground lead.
2 Release the lock down lever (1) and remove the transmission fluid level indicator from the filler tube (2).
Figure 7C4 – 56
3 Remove the bolt (1) attaching the filler tube (2) to the side of the right-hand cylinder head, refer to Figure 7C4 – 57.
4 Using a twisting and pulling motion, remove the filler tube from the seal (3) in the transmission case.
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Automatic Transmission – 4L60E – On-vehicle Servicing Page 7C4–43
If the verifier disc does not clip into place, the
quick-connect fitting is not engaged, rectify
as required.
10 As a security check, push and clip each verification disc into place over the quick-connect fittings. If difficulty is experienced, repeat the installation process until the verification disc can be clipped into place over the radiator
quick-connect fitting.
11 Snap the outlet cooler line (4) in the clip (5) of the radiator fan shroud.
12 Ensure the routeing of the cooler lines is correct and there is no fouling of the lines.
13 Tighten the screw attaching the cooler lines bracket to the correct torque specifications.
Transmission cooler lines bracket
attaching screw torque specification .................. 23.0 Nm
14 If required, top up the transmission fluid level (cold).
15 Start the engine and check for any fluid leak at the fittings. If a leak is found, stop the engine and rectify the leak.
16 Check and top up the transmission fluid to the correct level as required, refer to 2.1 Transmission Fluid.
3.18 Transmission Assembly
Remove
Disconnection of the battery affects certain
vehicle electronic systems. Refer to 6D1-3
Battery, before disconnecting the battery.
1 Disconnect the battery ground lead.
2 Raise the vehicle and support in a safe manner, refer to 0A General Information for the location of support points.
3 Remove the heat shield from the neutral start and back-up lamp switch, gently prise the selector cable from the transmission external manual shaft linkage and remove the selector cable from the bracket, refer to
3.3 Selector Cable Assembly.
4 Disconnect the harness connectors from the following:
a Vehicle speed sensor, refer to 3.5 Vehicle Speed Sensor.
b Neutral start and back-up switch, refer to 3.4 Neutral Start and Back-up Lamp Switch.
c For the following on four wheel drive vehicles (4W D), refer to 7D Transfer Case and Adaptor Housing:
• neutral switch,
• 2WD – 4WD shift actuator switch,
• speed sensor.
NOTE
If the battery is connected, avoid turning the
ignition switch to the ON position, as the transfer
case control module (TTCM) must first be
removed (memory to be cleared as Check 4W D
Indicator will light).
5 Remove the following components: a Front and centre exhaust assemblies, refer to 6F Exhaust System.
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