The P0959 trouble code relates to the auto shift manual mode circuit, indicating an intermittent issue.
P0959 Auto Shift Manual Mode Circuit Intermittent
Code symptoms P0959.
1. Intermittent inability to engage auto shift manual mode.
2. Erratic shifting behavior.
3. Poor transmission performance.
4. The Check Engine Light (CEL) may be illuminated intermittently.
Causes of the code P0959.
1. Intermittent connection in the auto shift manual mode circuit.
2. Faulty auto shift manual mode switch.
3. Wiring or connector issues in the auto shift manual mode circuit.
4. Faulty transmission control module (TCM).
Code Solutions P0959.
1. Inspect the wiring and connectors in the auto shift manual mode circuit for any damage, corrosion, or loose connections. Repair or replace any damaged wiring or connectors.
2. Test and replace the auto shift manual mode switch if it is faulty.
3. Diagnose and replace the faulty transmission control module (TCM) if necessary.
4. Perform a thorough inspection of the transmission system for any other electrical issues, such as loose connections or damaged components.