Isuzu KB P190. Manual — part 974

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–110

Step Action

Yes

No

3

1

Turn off the ignition.

2

Disconnect connector E-95 from the transmission.

N O T E

Additional DTCs may set

3

Install Tool No. J 44152 Jumper Harness (20 pins) on to the
harness connector E-95.

4

Turn on the ignition, with the engine off.

5

Using a test lamp, probe between connector E-95 pin 11 and a
known ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 4

4

1

Install Tool No. J44152 on 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 5

Go to Step 7

5

1

Remove Tool No. J44152 from the transmission.

2

Gain access to the TCC PWM solenoid and the control valve
body wiring harness, refer to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.

3

Disconnect the internal connector from the TCC PWM solenoid.

4

Using a multimeter set to measure resistance, probe across the
TCC PWM solenoid pins.

Does the multimeter display less than 20

Ω?

Replace the TCC

PWM solenoid, refer

to 7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing.

Go to Step 8

Replace the control

valve body wiring

harness, refer to

7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing

Go to Step 8

6

Using a multimeter, test between E-95 pin 11 and C-96 pin 14 for a
short to voltage.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

7

Replace the TCM, refer to 7C4 Automatic Transmission – 4L60E –
On-vehicle Servicing.

Did you complete the replacement?

Go to Step 8

—

8

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 / TCC Data.

4

Drive the vehicle in D4 and ensure the TCC Duty Cycle Circuit
parameter displays Okay for 5 seconds.

5

On Tech 2 select:
Diagnostic Trouble Codes / Read DTC Information.

Has DTC P2763 set?

Go to Step 2

Go to Step 9

9

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.

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–111

4.34 DTC P2764 – Torque Converter Clutch

Pressure Control Solenoid Control
Circuit Low Voltage

DTC Description

This diagnostic procedure supports DTC P2764 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control
Circuit Low Voltage.

Circuit Description

The torque converter clutch pulse width modulation (TCC PWM) 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 PWM 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 open or short to ground in the TCC PWM solenoid valve control circuit, then
DTC P2764 sets. DTC P2764 is a type A DTC.

Refer to 2

Wiring 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 P2764 sets when either of the following conditions occurs for 5 seconds:

•

The TCM detects an open in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded on.

•

The TCM detects a short to ground in the TCC PWM shift solenoid valve circuit when the TCC PWM is
commanded on.

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 P2764 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.

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–112

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 TCC PWM solenoid 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 TCC PWM solenoid valve.

9

Checks if the TCC PWM solenoid valve 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 P2764 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.

N O T E

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?

•

P0787

•

P0973

•

P0976

•

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

Automatic Transmission – 4L60E – Electrical Diagnosis

Page 7C2–113

Step Action

Yes

No

4

1

On Tech 2 select:
Transmission / Automatic Transmission / Miscellaneous
Tests / TCC PWM solenoid.

2

With Tech 2 command the TCC PWM solenoid ON and OFF
three times.

3

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 5

5

1

Turn off the ignition.

2

Disconnect connector E-95 from the transmission.

N O T E

Additional DTCs may set.

3

Install Tool No. J 44152 Jumper Harness (20 pins) on to the
harness connector E-95.

4

Turn on the ignition, with the engine off.

5

Using a test lamp, probe between connector E-95 pin 10 and a
known ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 15

6

1

Using a test lamp, probe connector E-95 pin 10 with the ground
lead to connector E-95 pin 19.

2

On Tech 2 select:
Automatic Transmission / Miscellaneous Tests / TCC PWM
Solenoid.

3

With Tech 2 command the TCC PWM Solenoid On and Off
three times.

Does the test lamp turn on and off with each command?

Go to Step 8

Go to Step 7

7

Is the test lamp always illuminated?

Go to Step 16

Go to Step 17

8

1

Remove Tool No. J44152 from the harness connector E-95 and
install on to the transmission connector E-95.

2

Using a multimeter set to measure resistance, probe across
transmission connector E-95 pins 10 and 19.

Does the multimeter display 10 – 15

Ω?

Go to Step 9

Go to Step 10

9

Using a multimeter set to measure resistance, probe between:

•

Transmission connector E-95 pin 10 and a known ground.

•

Transmission connector E-95 pin 19 and a known ground.

Does the multimeter display greater than 250 k

Ω in both instances?

Check for an

intermittent fault in

the circuit, refer to

8A Electrical-Body

and Chassis

Go to Step 11

10 1

Remove Tool No. J44152 from the transmission.

2

Gain access to the TCC PWM solenoid and the control valve
body wiring harness, refer to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.

3

Disconnect the internal connector from the TCC PWM solenoid.

4

Using a multimeter set to measure resistance, probe across the
TCC PWM solenoid pins.

Does the multimeter display 10 – 15

Ω?

Replace the control

valve body wiring

harness, refer to

7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing

Go to Step 19

Replace the TCC

PWM solenoid, refer

to 7C4 Automatic

Transmission –

4L60E – On-vehicle

Servicing.

Go to Step 19