Drive Motor Inverter Temperature Sensor Circuit Low
The P0AF4 code indicates that the powertrain control module (PCM) has detected a low voltage signal from the drive motor inverter temperature sensor circuit. This sensor monitors the temperature of the inverter, which converts DC battery power to AC for the electric motor. A low circuit condition typically means the sensor is reading an abnormally low temperature or there is a short to ground, an open circuit, or a faulty sensor. This can lead to inaccurate temperature readings, potentially causing the inverter to overheat or the vehicle to limit power to protect components.
01. Most Common Causes
- Faulty drive motor inverter temperature sensor
- Short to ground in sensor circuit
- Open circuit or damaged wiring/connector
- Corrosion or poor connection at sensor or PCM
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced motor power or performance
- Possible overheating of inverter
- Vehicle may enter limp mode
- No noticeable symptoms in some cases
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Visually inspect the inverter temperature sensor and wiring for damage, corrosion, or loose connections.
Step 3: Measure sensor resistance and compare to manufacturer specifications; replace if out of range.
Step 4: Check for short to ground or open circuit in the sensor signal wire using a multimeter.
Step 5: If wiring and sensor are okay, test PCM input/output; replace PCM if necessary.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can lead to inverter overheating and potential damage. The vehicle may limit power, but continued driving could cause component failure.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and sensor replacement, but can be higher if wiring repairs or PCM replacement is needed.