P0C16 is set by the motor B inverter when phase W runs too hot and the temperature sensor itself shows no fault. GM's tables give PIM sensor F above 98 °C for the 2011 Volt, above 88 °C with an 85 °C reset for the 2012 two-mode trucks, and 131 °C for 1.2 s within 2 s for the 2016 Volt, with 1.5 s in the 2019 table; each is Type A, one trip. Thermistor circuit codes such as P0BE0 and P0BE1 take priority and block the check. P0C14 and P0C15 are phases U and V, P0C13 is phase W on motor A. CARB allows some protective overtemperature strategies to run without MIL, but GM lights it here. Look for weak cooling first; until then motor B is derated.
High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
Symptoms
- Malfunction indicator lamp after one drive
- Reduced propulsion, notably at high load or high ambient temperature
- Hybrid system overheat message
Most likely causes
- Low coolant level or air in the power electronics loop
- Electric coolant pump of the inverter failed or blocked
- Dirty low-temperature radiator or inoperative fan
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It can trigger limp mode.
- It affects emissions.
What each character of P0C16 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- C: Subsystem depends on the code range
- 16: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0C16?
If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.
What causes code P0C16?
The most common causes are: low coolant level or air in the power electronics loop; electric coolant pump of the inverter failed or blocked; dirty low-temperature radiator or inoperative fan.
Related codes
- P0C14Drive Motor B Inverter Phase U Over Temperature
- P0C15Drive Motor B Inverter Phase V Over Temperature
- P0C13Drive Motor A Inverter Phase W Over Temperature
- P0BE0Drive Motor Inverter Temperature Sensor F Circuit
- P0BE1Drive Motor Inverter Temperature Sensor F Circuit Range/Performance
- P0A3DDrive Motor B Inverter Over Temperature
- P0C31Inverter B Cooling System Performance
Sources
- gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
- gsi.ext.gm.com: 12OBDG06 Hybrid Diagnostics
- gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.