P0963

P0963-PRESSURE CONTROL SOLENOID A CONTROL CIRCUIT HIGH





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


Theory of Operation


The Transmission Control Module (TCM) regulates the line pressure by pulsing the line pressure solenoid. The TCM monitors the line pressure solenoid voltage and current draw during operation.


- When Monitored:

Ignition on with a system voltage between 9.0 and 16.0 volts.


No Line Pressure Solenoid Circuit Low DTC present.

- Set Condition:

When the target line pressure solenoid current is greater than 0.75 amps while the monitored line pressure solenoid current is less than 0.4 amps for the period of 5.0 seconds.







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



Diagnostic Test


1. CHECK TO SEE IF THE DTC IS ACTIVE

With the scan tool, read Transmission DTCs.

Is the status Active for this DTC or is the STARTS SINCE SET counter 2 or less?

Yes

- Go To 2

No

- Go To 6



2. CHECK THE (T20) LINE PRESSURE SOLENOID CONTROL CIRCUIT





Turn the ignition off to the lock position.

Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.

Ignition on, engine not running.

With the scan tool, actuate the Line Pressure Solenoid.

Using a test light connected to ground, check the (T20) Line Pressure Solenoid Control circuit in the Transmission Solenoid/Pressure Switch Assembly harness connector.


NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 3

No

- Go To 5



3. CHECK THE (T20) LINE PRESSURE SOLENOID CONTROL CIRCUIT FOR A SHORT TO VOLTAGE





With the scan tool, stop the actuation of the Line Pressure Solenoid.

Turn the ignition off to the lock position.

Disconnect the TCM C1 harness connector.

Ignition on, engine not running.

Measure the voltage of the (T20) Line Pressure Solenoid Control circuit.

Is the voltage above .05 volts?

Yes

- Repair the (T20) Line Pressure Solenoid Control circuit for a short to voltage.
- Perform CVT VERIFICATION TEST. Verification Tests

No

- Go To 4



4. CHECK THE LINE PRESSURE SOLENOID





Turn the ignition off to the lock position.

Reconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.

Measure the resistance between ground and the (T20) Line Pressure Solenoid Control circuit in the TCM C1 harness connector.

Is the resistance between 3.0 and 9.0 ohms?

Yes

- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM.
- Perform CVT VERIFICATION TEST. Verification Tests

No

- Replace the CV Transmission or replace the Line Pressure Solenoid (Valve Body).
- Perform CVT VERIFICATION TEST. Verification Tests



5. CHECK THE (T20) LINE PRESSURE SOLENOID CONTROL CIRCUIT FOR AN OPEN





Turn the ignition off to the lock position.

Measure the resistance of the (T20) Line Pressure Solenoid Control circuit between the TCM C1 harness connector and the Transmission Solenoid/Pressure Switch Assembly harness connector.

Is the resistance above 5.0 ohms?

Yes

- Repair the (T20) Line Pressure Solenoid Control circuit for an open.
- Perform CVT VERIFICATION TEST. Verification Tests

No

- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for any Service Bulletins for possible causes that may apply. If no problems are found, replace the TCM.
- Perform CVT VERIFICATION TEST. Verification Tests



6. INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this 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.

Were there any problems found?

Yes

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

No

- Test Complete.