Powertrain, generic (extended)

P2CC8 Coolant Pump Speed Sensor Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Some engines measure how fast a coolant pump turns with a dedicated speed sensor, for instance on a pump that can be engaged and released or on an electric pump read back by the controller. P2CC8 is the general fault of that sensor's circuit: the signal is absent or cannot be used, without the controller deciding whether it is too low or too high. No manufacturer documents P2CC8 publicly. GM's patent US20160047374A1 describes how a measured pump speed, compared with the target, lets the controller diagnose an electric main coolant pump; Audi's patent US8915127B2 shows that without such a signal a switchable pump can only be judged indirectly through cylinder head temperature. CARB requires monitoring of coolant flow devices other than a thermostat. Expect a MIL and a default pump state.

Likely causes

Failed speed sensor delivering no usable signal
Damaged wiring or loose connector at the sensor
Missing reference voltage or ground for the sensor

Symptoms

  • MIL on
  • Coolant pump held in a default state, warm-up may change

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–400
Time0.5–2 h

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

Parts involved

coolant pump speed sensorwiring harnessecm

Related codes

P2CC9P2CCAP2CCBP2B85P26CE

References: law.cornell.edu, patents.google.com, patents.google.com.