P0965

Symptoms

• Check engine light
• transmission slipping in and out of gear
• harsh shifting
• transmission overheating
• limp mode (limited speed, transmission may stop shifting entirely)
• engine stalling
• misfire-like symptoms
• increased fuel consumption.

Probable causes

• Low
• degraded or contaminated transmission fluid (clutch material clogging the solenoid passages and making it stick) is one of the most common causes. Also: faulty pressure control solenoid B (electrically shorted/open coil or mechanically stuck)
• damaged wiring or broken/corroded connectors on the transmission harness (moisture and road-salt corrosion at the main transmission connector)
• failing transmission pump
• valve body failure
• TCM/PCM problems.

Diagnostic steps

1. Scan for codes and freeze-frame data; note any companion transmission codes.
2. Check transmission fluid level and condition first - low or dirty fluid is one of the most common causes; service fluid and filter if degraded or contaminated.
3. Inspect the transmission wiring harness and the main transmission connector for damage, corrosion and moisture intrusion; repair as needed.
4. Test the pressure control solenoid B circuit and the solenoid itself per manufacturer service data; replace the solenoid if it fails electrical or mechanical testing.
5. If fluid, wiring and solenoid check good, investigate hydraulic causes - transmission pump and valve body.
6. Only after that, evaluate the TCM/PCM. Repair promptly: continued driving with an active P0965 can destroy clutch packs and the torque converter, escalating a solenoid-level repair into a full transmission rebuild.