P0746

Diagnostic Chart:

Diagnostic Chart (cont'd):

Wiring Diagram:

During normal driving modes the PCM/TC adapts line pressure to prevent clutch slip and harsh shifts. This is accomplished by modulating the transaxle fluid pressure (TFP) actuator ground (1530) to raise or lower pressure. Open circuit = high pressure, grounded circuit = low pressure. When the PCM opens the circuit the voltage is monitored to check for proper circuit conditions.

DTC PARAMETERS

DTC P0746 is set when the PCM has detected the following condition at twice per ignition cycle.

- Voltage monitored at terminal J4A03 (circuit 1530) is less than 2 - 2.5 volts when the line pressure 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 TRS LP fuse is ok, check for battery voltage on fuel pump relay side of fuse with engine running.

3. This step checks for a ground in circuit 1525. A ground in circuit 1525 will cause the TRS LP fuse to fail and set DTC P0746.

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

5. An open in circuit 1525 will cause DTC P0746 to set. Check circuit 1525 for opens.

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

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

8. An open or a ground in circuit 1530 will set DTC P0746. This step checks circuit 1530 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 actuators and no active faults exist 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 may set or intermittent harsh upshifts may be caused by 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.

- No 2nd, 3rd, 4th gear 732, 733, 734 DTCs set if circuit grounded: low line. (Will not shift out of first.)

- If circuit is open = high line pressure.

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.