Obdaryn

P2796Electric/Auxiliary Transmission Fluid Pump A Control Circuit/Open

  • Generic OBD-II code · Powertrain
  • Turns on the check-engine light
  • Matters for the ITP
  • Can trigger limp mode
How the car detects it
P2796 points to an interrupted control line between the module and the motor of auxiliary pump A. GM's 2025 TCM tables define the test: provided the battery supplies 9 to 15 V, the controller sees more than 200 kΩ from signal to ground in at least 20 of 25 samples taken every 100 ms; the code is Type B, so the MIL comes on after two trips. On Ford's 10R60/10R80 and 8F57 automatics the pump itself reports that the PWM command signal is missing, filed as P2796_31. Ford TSB 26-2010 covers the 2022–2025 F-150 Lightning, where P2796 or P2797 in the secondary OBD modules B and C may stem from software, often first logged at 0 °C or below; reprogramming is the fix. P2798 and P2799 are the short-circuit siblings, P27A2 the same fault on pump B.
What you may notice
  • MIL or wrench indicator on
  • Stop-start inoperative
  • Reduced performance message on electrified models
Likely causes
  • LikelyBroken control wire or unplugged pump connector
  • PossiblePoor terminal contact at the pump or module
  • PossibleModule software (Ford F-150 Lightning, TSB 26-2010)
  • RareOpen circuit inside the pump electronics
Inspection (ITP)
Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
Repair
Medium · Usually a job for a workshop.Typical cost: €0 – €900

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.