Powertrain, generic · Hybrid propulsion

P0C15 Drive Motor B Inverter Phase V Over Temperature

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P0C15 reports overtemperature at phase V of the motor B inverter, based on a sensor reading that is valid but above the limit. GM applies it on the Volt and the two-mode trucks: PIM sensor D above 98 °C on the 2011 Volt, 88 °C on the 2012 trucks, 102.5 °C on the 2016 ELR, 131 °C for 1.2 s within 2 s on the 2016 Volt and in the 2018 table, every time Type A with one trip. It is a protective diagnosis, not a wiring check; the thermistor's own codes P0BD6 and P0BD7 handle sensor faults. Phase U and W are P0C14 and P0C16, phase V on motor A is P0C12. GM bulletin PIC6303A names P0C15 among the overheat codes that call for a cooling diagnosis. Motor B output is restricted.

Likely causes

Coolant loss or air in the inverter cooling loop

Electric coolant pump of the power electronics not working

Blocked radiator for the power electronics or fan failure

Poor heat transfer or ageing power stage inside the inverter

Symptoms

Malfunction indicator lamp after one drive
Reduced propulsion until the inverter has cooled
Engine runs more often than usual

Repair estimate

DifficultyHardWorkshop job

Parts and labour€50–3,500

Time0.5–5 h

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

Parts involved

drive motor b inverter phase v

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