Powertrain, generic · Hybrid propulsion

P0C2A Electric/Auxiliary Transmission Fluid Pump A Motor Stalled

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P0C2A means motor A of the auxiliary pump is commanded but does not turn, or turns far slower than required. Ford documents it in TSB 17-2056 for the 2016 F-150 2.7L with start-stop built from 1 May 2016: with the fluid above 38 °C the technician commands the pump through the PCM at duty cycles from 20 to 90 percent; if it runs, the PCM gets new software, if not, the auxiliary pump is replaced. GM shows how a stall is detected on the ELR pump controller, under its own code P1E3A: commanded minus actual speed above 200 rpm while more than 6.8 Nm is requested, Type A. Sensorless pumps cannot measure speed directly, so a stall shows up as a speed or current mismatch. P0C29 covers the driver stage, P0C28 overcurrent.

Likely causes

Auxiliary pump seized or jammed by debris (Ford F-150 2.7L replaces the pump)
PCM calibration causing false stall detection (Ford TSB 17-2056)
Very cold, thick fluid or wrong fluid type raising drag
Open phase so the motor cannot develop torque

Symptoms

  • MIL on
  • Start-stop inactive, harsh engagement after stops

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.4–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

aux trans pump a motor

Related codes

P0C26P0C27P0C28P0C29P2797

References: static.nhtsa.gov, gsi.ext.gm.com, law.cornell.edu.