What it means
The control module detects a fault in the drive motor inverter temperature sensor B circuit. The code alone does not establish whether the sensor or its wiring is at fault.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Temperature sensor B provides the control module with a reading of the drive motor inverter’s temperature. The module monitors the sensor’s electrical circuit, and sets P0AF2 when it detects a circuit fault; this code alone does not say whether the sensor or its wiring is responsible.
Common causes
Most likely first.
- Sensor failed
- Wiring or connector fault
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Read freeze-frame data and live data for inverter temperature sensor B, along with related hybrid-system codes, to see when the fault occurred and whether the reading is missing or implausible.
- With the vehicle powered down according to the manufacturer’s high-voltage safety procedure, inspect sensor B’s connector and accessible wiring for damage, moisture, corrosion, or a loose fit.
- Check the sensor B circuit connections and wiring continuity for opens, shorts, or poor contact using the manufacturer’s diagnostic procedure.
- Test sensor B and its circuit against the manufacturer’s specification to distinguish a failed sensor from a wiring or connector fault.
- After repairs, clear the code and confirm sensor B data is stable during the manufacturer’s prescribed verification procedure.
Common fixes
- Reseat and secure the sensor B connector.
- Repair damaged or poorly connected wiring in the sensor B circuit.
- Clean or repair corroded sensor B connector terminals.
- Replace drive motor inverter temperature sensor B if it fails the specified test.
Can I keep driving?
Avoid relying on the vehicle for normal driving because it may limit motor power or shut down. If power is reduced or a hybrid-system warning appears, stop somewhere safe and arrange service.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.