Transmission Park Position Sensor Circuit Open
The P07B8 code indicates an open circuit in the transmission park position sensor/switch circuit. This sensor tells the PCM (Powertrain Control Module) when the transmission is in Park. An open circuit means there is a break in the electrical path, preventing the sensor signal from reaching the PCM. This can be caused by a faulty sensor, damaged wiring, or a poor connection. The PCM may not know the transmission is in Park, affecting starting and safety systems.
1. Symptoms You Will Notice
- Engine may not start in Park
- Engine may start in other gears
- Check Engine Light illuminated
- Transmission may not shift properly
2. Most Common Causes
- Faulty park position sensor/switch
- Open or shorted wiring in the sensor circuit
- Corroded or loose electrical connector
- Damaged PCM (rare)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the park position sensor connector and wiring for damage or corrosion.
Step 3: Test the sensor circuit for continuity using a multimeter.
Step 4: Check sensor resistance and compare to manufacturer specs.
Step 5: If sensor and wiring are good, test PCM input/output signals.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The vehicle may not start or could start in gear, posing a safety risk. Have it diagnosed promptly.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and repair, depending on the cause. Sensor replacement is usually under $100, plus labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.