P0AF2Drive Motor Inverter Temperature Sensor B Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Inverter temperature sensor B is, in GM's hybrid tables, the phase U thermistor of the second inverter, the one that drives motor B in two-motor systems. P0AF2 is its general circuit code for an electrical fault that the controller does not narrow down to low, high or erratic. No manufacturer documents this exact code publicly; GM's tables report the specific siblings P0AF3, P0AF4 and P0AF5 instead. CARB requires monitoring of hybrid components and their sensor circuits. Without a valid temperature the controller cannot protect the power switches of inverter B and usually limits that motor's torque. Whether a vehicle uses sensor B at all depends on its layout, so read the full code list and check the inverter connectors.
- What you may notice
- Hybrid system warning or check engine lamp
- Reduced electric drive or generator power
- Higher fuel consumption in hybrid operation
- Likely causes
- LikelyInternal fault of the sensor inside the power inverter module
- PossibleCorroded or loose connector at the inverter module
- RareSoftware fault in the motor control processor
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.