Drive Motor Inverter Temperature Sensor Circuit Low
The P0BD8 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 drive motor. A low circuit condition typically means the signal voltage is below the expected range, possibly due to a short to ground, faulty sensor, or wiring issues. This can lead to inaccurate temperature readings, potentially causing the inverter to overheat or the vehicle to limit power to protect components.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced motor power or performance
- Overheating of the inverter or drive motor
- Vehicle may enter limp mode
- Inaccurate temperature gauge or warning messages
2. Most Common Causes
- Faulty or degraded inverter temperature sensor 'D'
- Short to ground in the sensor wiring
- Corroded, oxidized, or damaged pins in the sensor connector
- Excessive resistance in the sensor circuit due to poor splices or deteriorated wires
- Internal inverter failure affecting the sensor circuit
- Issue with the transmission or electric drivetrain control module
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all stored codes and freeze frame data.
Step 2: Visually inspect the inverter temperature sensor and wiring for damage, corrosion, or loose connections.
Step 3: Measure the sensor resistance and compare to manufacturer specifications; replace if out of range.
Step 4: Check for short to ground by disconnecting the sensor and measuring voltage at the harness connector.
Step 5: If wiring and sensor are okay, test the PCM output signal; replace PCM if necessary.
4. 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.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.