Shift solenoid 4 is used to supply and relieve fluid pressure to the 4^th gear clutch pack. Shift solenoid 4 is turned electrically ON/hydraulically OFF, relieving pressure to 4^th gear clutch, during 1^st , 2^nd and 3^rd gear operation. The powertrain control module (PCM) controls shift solenoid 4 by controlling an internal driver that pulls the solenoid circuit to ground. During normal 4^th gear shift operation, the PCM will turn OFF, open the driver, shift solenoid 4 and keep it OFF until a downshift occurs. The PCM will PWM the pressure control solenoid to adapt shift timing. The shift solenoid 4 circuit is monitored for low and high voltage faults. DTC P0768 sets when shift solenoid 4 is commanded ON and the feedback voltage at the PCM is high.

DTC P0768 will set if shift solenoid 4 feedback voltage is greater than 1.25 volts with shift solenoid 4 commanded ON when:

DTC P0768 diagnostic runs continuously with fuel pump relay and shift solenoid 4 commanded ON.

DTC P0768 is a type D DTC.

*Applicable to vehicles built after June 2000.

To locate an intermittent problem, start engine with transaxle in Park and use scan tool to monitor the SHIFT SOL. 4 - HIGH VOLT test. When a fault, short to voltage or shorted solenoid exists, the Scan tool will display TEST FAIL.

The test will fail only when the device is being commanded ON and the voltage at the PCM is high. The test updates every 100 milliseconds whenever the ignition is turned ON and the device is being commanded ON via the scan tool or PCM.

If a short across the solenoid or a short to voltage on circuit 898 exists, the PCM will open the driver circuit for protection and the feedback voltage will be high.

Shift solenoid 4 resistance: 3.8-7.2 ohms

Nominal value: 4.5 ohms at 68°F