P0745

P0745-LINE PRESSURE SOLENOID CIRCUIT





For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The Linear Solenoid 4 is used to control overall transmission line pressure. The TCM monitors the Solenoid current load and resistance. If a fault is detected, the transmission will go into limp in mode, the Torque Converter Clutch (TCC) will be disabled, and the MIL will be illuminated.



When Monitored:
- Ignition on, engine running.

Set Condition:
- Solenoid current is greater than or equal to 4 amps for more than 100 ms or Solenoid resistance is greater than or equal to 100k ohms for more than 65 ms.







Always perform the AS68RC Pre-Diagnostic Troubleshooting procedure before proceeding. AS68RC Pre-Diagnostic Troubleshooting Procedure



Diagnostic Test


1. CHECK IF DTC IS CURRENT

With the scan tool, view Transmission DTCs.

Is the status Active or is the Starts Since Set counter 2 or less for this DTC?

Yes

- Go To 2

No

- Go To 11



2. CHECK THE (T821) LINEAR SOLENOID 4 CONTROL CIRCUIT FOR AN OPEN





Turn the ignition off to the lock position.

Disconnect the Transmission Solenoid Assembly C2 harness connectors.

Disconnect the TCM C3 harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (T821) Linear Solenoid 4 Control circuit between the Transmission Solenoid Assembly C2 harness connector and the TCM C3 harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 3

No

- Repair the (T821) Linear Solenoid 4 Control circuit for an open.
- Perform AS68RC VERIFICATION TEST. Verification Tests



3. CHECK THE (T821) LINEAR SOLENOID 4 CONTROL CIRCUIT FOR A SHORT TO GROUND





Measure the resistance between ground and the (T821) Linear Solenoid 4 Control circuit.

Is the resistance below 100k ohms?

Yes

- Repair the (T821) Linear Solenoid 4 Control circuit for a short to ground.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Go To 4



4. CHECK THE (T821) LINEAR SOLENOID 4 CONTROL CIRCUIT SHORT TO VOLTAGE





Ignition on, engine not running.

Measure the voltage of the (T821) Linear Solenoid 4 Control circuit.

Is the voltage above 0.5 volt?

Yes

- Repair the (T821) Linear Solenoid 4 Control circuit for a short to voltage.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Go To 5



5. CHECK THE (T821) LINEAR SOLENOID 4 CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT





Turn the ignition off to the lock position.

Measure the resistance between the (T821) Linear Solenoid 4 Control circuit and all other circuits in the Transmission Solenoid Assembly C2 harness connector.

Is the resistance below 100k ohms between the (T821) Linear Solenoid 4 Control circuit and any other circuit in the Transmission Solenoid Assembly harness connector?

Yes

- Repair the (T821) Linear Solenoid 4 Control circuit for a short to another circuit(s).
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Go To 6



6. CHECK THE (T818) LINEAR SOLENOID 4 GROUND CIRCUIT FOR AN OPEN





Measure the resistance of the (T818) Linear Solenoid 4 Ground circuit between the Transmission Solenoid Assembly C2 harness connector and the TCM C3 harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 7

No

- Repair the (T818) Linear Solenoid 4 Ground circuit for an open.
- Perform AS68RC VERIFICATION TEST. Verification Tests



7. CHECK THE (T818) LINEAR SOLENOID 4 GROUND CIRCUIT FOR A SHORT TO GROUND





Measure the resistance between ground and the (T818) Linear Solenoid 4 Ground circuit.

Is the resistance below 100k ohms?

Yes

- Repair the (T818) Linear Solenoid 4 Ground circuit for a short to ground.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Go To 8



8. CHECK THE (T818) LINEAR SOLENOID 4 GROUND CIRCUIT SHORT TO VOLTAGE





Ignition on, engine not running.

Measure the voltage of the (T818) Linear Solenoid 4 Ground circuit.

Is the voltage above 0.5 volt?

Yes

- Repair the (T818) Linear Solenoid 4 Ground circuit for a short to voltage.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Go To 9



9. CHECK THE (T818) LINEAR SOLENOID 4 GROUND CIRCUIT SHORT TO ANOTHER CIRCUIT





Turn the ignition off to the lock position.

Measure the resistance between the (T818) Linear Solenoid 4 Ground circuit and all other circuits in the Transmission Solenoid Assembly C2 harness connector.

Is the resistance below 100k ohms between the (T818) Linear Solenoid 4 Ground circuit and any other circuit in the Transmission Solenoid Assembly C2 harness connector?

Yes

- Repair the (T818) Linear Solenoid 4 Ground circuit for a short to another circuit(s).
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Go To 10



10. CHECK THE LINEAR SOLENOID 4





Turn the ignition off to the lock position.

Reconnect the Transmission Solenoid Assembly C2 Harness connector.

Measure the resistance between the (T821) Linear Solenoid 4 Control and the (T818) Linear Solenoid 4 Ground circuit on the appropriate terminals of the TCM C3 harness connector.

Is the resistance of the Linear Solenoid 4 5.5 ohms (± 0.5 ohms)?

Yes

- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the TCM.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Replace the Linear Solenoid 4.



11. CHECK WIRING AND CONNECTORS

The conditions necessary to set the DTC are not present at this time.

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle the wires while checking for shorted and open circuits.

Check for any Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Test Complete.