P0740

Diagnostic Chart:

Diagnostic Chart (cont'd):

Wiring Diagram:

The torque converter clutch (TCC) solenoid valve is applied when circuit 422 is grounded at the PCM. When the PCM opens the circuit the voltage is monitored at terminal J4A02 to check for proper circuit conditions.

DTC PARAMETERS

DTC P0740 is set when the PCM has detected the following condition twice per ignition cycle.

^ Voltage monitored at terminal J4A02 (circuit 422) is less than 2-2.5 volts when the actuator is switched off electrically by the PCM.


TEST DESCRIPTION

Numbered steps below refer to numbered steps on chart.

1. This step verifies problem is still present.

2. If the TCC fuse is ok, check for battery voltage on fuel pump relay side of fuse with engine running or PCM in diagnostic mode.

3. This step checks for a ground in circuit 1526A. A ground in circuit 1526A will cause the TCC fuse to fail and set TCC P0740.

4. A faulty actuator or connector plate could have blown the TRS 2/TCC fuse. This step checks for low resistance.

5. An open in circuit 1526A will cause DTC P0740 to set. Check circuit 1526A for opens.

6. This step will determine if fault is in the circuit to PCM or in the actuator or connector plate.

7. This step will determine if the fault is in the actuator or in the connector plate.

8. An open or a ground in circuit 422 will set DTC P0740. This step checks circuit 422 for opens or grounds.

REPAIR VERIFICATION

Monitor DTC menu "Code Status" for "Pass Since Code Clear" and "Pass This Ignition Cycle." When both have passed, repair is verified.

Criteria for pass:

^ Engine running, power present at all actuators and active faults are not present for this actuator.

DIAGNOSTIC AIDS

When attempting to diagnose an intermittent problem use the Scan tool* to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

* Select MALF History and DTC status from DTC menu of Scan tool.

^ This DTC P0741 - No TCC may set because of a poor electrical connection at either the PCM, actuator connector plate or Under Hood Junction Block (UHJB) terminals. Wiggling connectors while performing an actuator quick test may help isolate the problem area.

Check the tightness of the female terminal grip with a spare male terminal.

When the PCM detects a fault in the circuit (open, ground, short) the PCM will open the circuit internally to protect the circuit.

^ An open circuit will probably also set a DTC P0741 - No TCC.

^ A grounded circuit 472 will probably also set a DTC P0742 TCC Stuck On.