Powertrain, generic · Hybrid propulsion

P0CBD Drive Motor A Coolant Temperature Sensor Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0CBD reports that the coolant temperature sensor of drive motor A gives a believable voltage but an implausible temperature. GM uses it on the 2013 eAssist models, where the drive motor is the belt-driven motor generator with its own small cooling loop. Table 13OBDG05C runs the check once per key cycle after an engine-off period of more than 21,600 s: the loop sensor is compared with the mean of stator temperature, intake air temperature and transmission fluid temperature, and a difference above 25 °C in 50 of 62 samples at 100 ms is a Type B fault. The test is skipped while stator sensor codes P0A2B–P0A2D, intake air or transmission fluid sensor codes, the sensor's own P0CBE/P0CBF or CAN faults U0100/U0101 are active. A drifting sensor is the likely cause; the motor generator may be limited meanwhile.

Likely causes

Coolant temperature sensor drifted out of its curve
Added resistance from a corroded connector
One of the comparison sensors (stator, intake air, transmission oil) reading wrongly

Symptoms

  • Check-engine lamp after the second faulty trip
  • Reduced electric assist or regeneration

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–450
Time0.5–2 h

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

Parts involved

drive motor a coolant temp sensorwiring harnesshybrid control module

Related codes

P0CBCP0CBEP0CBFP0CC0P0A2BP0CC2

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