P2789 Possible Causes
- Low transmission fluid
- Internal mechanical transmission failure
- Faulty transmission control module (TCM)
How to Fix Code P2789
Check the “possible causes” listed above. Visually inspect the wiring harness and related connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
Check engine light on (or service engine soon warning light)
P2789 Meaning
The transmission control module (TCM) monitors the adaptive learning of clutch “A”. The TCM sets the OBDII code when it detects an abnormality in the adaptive learning system of clutch “A”.