The P0777 error code on a Jeep Compass indicates a problem with the transmission’s electronic pressure control solenoid. This article details troubleshooting steps taken to address this issue, along with a routine CVT maintenance procedure. The process involved checking wiring, solenoids, and performing a TCM reset.
Initially, the troubleshooting focused on addressing both P0746 and P0777 error codes. The transmission connector, located on the driver’s side of the transmission body, was accessed by removing the engine cover and tire. This provided access to perform tests and checks. A visual inspection of the connector revealed no apparent damage.
Following the initial inspection, standard CVT maintenance was performed, including a CVT oil and filter change. During this process, new primary and secondary sensors (Sonar brand) and a stepped motor were also installed. Although the service manuals were helpful, a leak was discovered after using the ATP-235 gasket kit, despite applying the recommended torque of 70 in/lb.
Unfortunately, the P0746 and P0777 codes persisted after the maintenance. A quick reset of the TCM module using JScan was performed, followed by a test drive. The original errors remained, and new error codes appeared.
Further troubleshooting included checking the wiring, solenoids, and the stepped motor. All components showed the expected resistance values. However, attempting to test the voltage of the Line and Secondary solenoids using JScan resulted in an error.
Since the wiring was ruled out, the next step is to replace the solenoids with remanufactured units. Finding brand new solenoids has proven difficult. The gasket leak will also be addressed. Further investigation into actuating the solenoids using JScan or other OBD apps is needed. Information on sourcing brand new solenoids is also welcome. The possibility of a faulty TCM module will be considered if the problem persists after replacing the solenoids.
