Powertrain, generic · Hybrid propulsion

P0AF2 Drive Motor Inverter Temperature Sensor B Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

Internal fault of the sensor inside the power inverter module
Corroded or loose connector at the inverter module
Software fault in the motor control processor

Symptoms

  • Hybrid system warning or check engine lamp
  • Reduced electric drive or generator power
  • Higher fuel consumption in hybrid operation

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–4,000
Time1–6 h

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

Parts involved

drive motor inverter temp sensor bhybrid control modulewiring harness

Related codes

P0AF3P0AF4P0AF5P0AF6P0AEDP0A3D

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