Drive Motor Position Sensor Circuit High Voltage
The P0A42 code indicates that the Powertrain Control Module (PCM) has detected a voltage signal from the drive motor position sensor that is higher than the expected range. This sensor is critical for monitoring the rotor position of the electric drive motor, which is used for precise control of motor operation. A high voltage condition can be caused by a faulty sensor, wiring issues, or a malfunctioning PCM. This code is specific to hybrid and electric vehicles.
01. Most Common Causes
- Faulty drive motor position sensor
- Short to voltage in sensor circuit wiring
- Damaged connector or corroded terminals
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced motor power or performance
- Vehicle may enter limp mode
- Possible stalling or inability to start
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0A42 and check for additional codes.
Step 2: Visually inspect the drive motor position sensor connector and wiring for damage, corrosion, or shorts.
Step 3: Measure voltage at the sensor signal wire with the ignition on; compare to manufacturer specifications.
Step 4: If voltage is high, disconnect the sensor and check if voltage drops; if not, repair short to voltage in wiring.
Step 5: If sensor is suspected, replace the drive motor position sensor and clear codes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The vehicle may experience reduced power or unexpected shutdown, which could be dangerous, especially in traffic.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts and labor. Sensor replacement is the most common fix.