Powertrain, generic · Hybrid propulsion

P0C1F Electric/Auxiliary Transmission Fluid Pump Control Module Internal Temperature Sensor Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C1F means the internal temperature sensor of the auxiliary pump module delivers a voltage above its valid range, which for an NTC thermistor reads as an implausibly cold board and usually indicates an open sensor path. No manufacturer documents this exact code publicly. GM's ELR pump controller of 2016 shows the matching case under its own code P1E34, labelled circuit high: below -58 °C, near 5 V, for 250 of 350 samples sets the fault, Type B in the ELR tables. With such a value the controller loses its overtemperature protection; the Honda CVT pump patent shows that this protection is what keeps the driver board alive, so the pump is typically restricted. P0C1E is the low side, P0C1D the plausibility check, P0C1B real overtemperature.

Likely causes

Board temperature sensor open or its solder joint cracked
Measuring circuit of the pump control module faulty
Ground offset at the pump module shifting the sensor voltage

Symptoms

  • MIL after two drive cycles
  • Start-stop restricted, pump in protective mode

Repair estimate

DifficultyHardWorkshop job
Parts and labour€300–1,800
Time1–4 h

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

Parts involved

aux trans pump control module

Related codes

P0C1BP0C1CP0C1DP0C1E

References: law.cornell.edu, gsi.ext.gm.com, patents.google.com.