OBD-II Generic Error Code P2797: How to Fix It

Q: Can I still drive my car with a P2797 code?

Short trips may be possible, but driving with P2797 is not recommended. The auxiliary transmission fluid pump is responsible for maintaining fluid pressure and cooling, especially during stop-and-go driving or when the engine is off in hybrid vehicles. Without proper pump performance, your transmission can overheat or experience premature wear. Have the issue diagnosed as soon as possible to avoid costly transmission damage.

Q: What vehicles commonly get code P2797?

P2797 is most frequently seen in hybrid vehicles — such as Toyota Highlander Hybrid, Lexus RX450h, Toyota Camry Hybrid, and similar models — as well as certain GM, Ford, and Chrysler vehicles equipped with electronically controlled automatic transmissions that use an auxiliary electric pump. Check your owner's manual or a vehicle-specific forum to understand how critical this pump is for your specific model.

Q: How much does it cost to fix P2797?

Costs vary widely depending on the root cause. Cleaning a corroded connector may cost nothing beyond your time. Replacing a transmission fluid filter and fluid typically runs $100–$250. Replacing the auxiliary transmission fluid pump itself can range from $200 to over $800 in parts, plus $150–$400 in labor depending on accessibility. If the TCM needs reprogramming, expect an additional $100–$200 at a dealership.

Q: Can low transmission fluid cause P2797?

Yes. Low or degraded transmission fluid can cause the auxiliary pump to work harder to maintain pressure, resulting in reduced performance and triggering P2797. Always check and correct the transmission fluid level and condition first before replacing any components — it is the easiest and cheapest fix to rule out.

Q: Will P2797 go away on its own?

It is unlikely to resolve itself without intervention. While clearing the code and retesting may temporarily make it disappear, the underlying issue — whether it is a failing pump, bad wiring, low fluid, or a clogged filter — will cause the code to return. Ignoring it risks escalating from a medium-severity issue to major transmission damage, so it is best to diagnose and repair the root cause promptly.

Abstract

Error code P2797 indicates that your vehicle's auxiliary transmission fluid pump is not performing as expected — it may be running too slowly, delivering insufficient pressure, or failing to respond to commands from the transmission control module (TCM). This pump is commonly found in hybrid vehicles and certain automatic transmissions to maintain fluid pressure and cooling when the engine is off or during low-speed operation. Left unaddressed, this issue can lead to transmission overheating, slipping gears, or long-term internal damage.