Powertrain, generic · Hybrid propulsion

P0C24 Electric/Auxiliary Transmission Fluid Pump Control Module Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0C24 means the circuit from the controlling module to the auxiliary pump control module is held low, typically a short to ground on the command line. No manufacturer documents this exact code publicly. How the line is used is visible in Ford's 2016 F-150 2.7L bulletin, where the PCM commands the start-stop pump by duty cycle and the technician checks the pump by sweeping that command from 20 to 90 percent. A grounded line leaves the pump without a valid command or, depending on logic, permanently off. GM's ELR pump controller likewise depends on its wake-up signal to run. CARB requires output circuits of such components to be monitored. P0C23 is the open circuit, P0C25 the high side, P2796 to P2798 the classic pump control circuit codes.

Likely causes

Command wire shorted to ground, e.g. chafed at the transmission case
Fluid or corrosion in the pump connector pulling the line low
Output stage in the PCM/TCM or input of the pump module faulty

Symptoms

  • No engine auto-stop
  • MIL or transmission warning

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,500
Time0.5–3 h

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

Parts involved

aux trans pump control modulewiring harnesstcm

Related codes

P0C23P0C25P0C2DP2796P2798

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