Powertrain, generic · Hybrid propulsion

P0CBE Drive Motor A Coolant Temperature Sensor Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0CBE says the coolant temperature input of drive motor A is below its valid range, meaning the sensor resistance has become very small. GM's 2013 eAssist table 13OBDG05C sets the code when the raw reading is under 100.9 Ω, which equals 120 °C, in 50 of 62 samples taken every 100 ms with the vehicle in run/crank; it is a Type B fault, so the lamp comes on after the second trip. Such a low value is usually a shorted sensor or a signal line rubbing through to ground. GM's preliminary information PIC5720A for 2012–2013 LaCrosse and Regal, 2013 Malibu Eco and 2014 Impala Eco with eAssist describes exactly that: a misrouted harness touching the crank, A/C compressor pulley or belt, together with C027B and C0040 and a humming noise. Its partner for an open circuit is P0CBF.

Likely causes

Harness rubbing on crank or compressor pulley or belt (GM PIC5720A)
Coolant temperature sensor shorted internally
Loop genuinely very hot, e.g. pump or coolant fault

Symptoms

  • Check-engine lamp, possibly with ABS or brake assist warning
  • Hum or buzz from the right front
  • Electric assist restricted

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–500
Time0.5–2.5 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

P0CBFP0CBDP0CBCP0CC0P0A2C

References: gsi.ext.gm.com, static.nhtsa.gov.