Electric/Auxiliary Transmission Fluid Pump A Performance/Stuck Off
What it means
P2797 means the electric auxiliary transmission fluid pump isn't performing — it appears stuck off or not building the expected pressure. This pump keeps the transmission lubricated and cooled while the engine is stopped (auto start-stop and hybrid driving), so the main risks are disabled start-stop and the transmission running hotter than intended. It's usually an electrical or pump-motor fault rather than a mechanical transmission failure.
Can I keep driving? Usually yes for now, but watch for overheating — the auxiliary pump keeps the transmission fed during engine stop, so start-stop and hybrid drive may be affected.
Common symptoms
What you'll notice
- Check-engine light on
- Auto start-stop disabled, or hybrid engine restarts more often
- Transmission runs hotter, with possible over-temp warning
- Delayed or firm engagement after the engine auto-restarts
Common causes
Most likely first
- Failed auxiliary fluid pump motor (stuck off / not building pressure)Likely
- Blown fuse or faulty pump control relay/driverCommon
- Open, shorted, or corroded wiring to the pumpCommon
- Poor connector contact at the pump or transmission controllerLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for related transmission or hybrid codes.
- Check the pump fuse and relay; confirm the pump is commanded on with a scan tool.
- Verify power and ground reach the pump when commanded; check the connector for corrosion.
- If wiring and control are good but the pump doesn't run, replace the auxiliary fluid pump.
- Clear the code and confirm start-stop / auxiliary pump operation returns to normal.
FAQ
Quick answers
Is it safe to drive with P2797?+
Can I just clear P2797?+
Related codes
Often seen with P2797
Read & clear P2797 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.