Transmission Park Position Sensor/Switch Circuit Performance/Low
The P07BB code indicates that the transmission control module (TCM) has detected a performance or low voltage issue in the park position sensor/switch circuit. This sensor tells the TCM when the transmission is in park, which is critical for starting the engine and engaging the park lock. A fault can prevent the engine from starting or cause the vehicle to not recognize park, leading to safety concerns.
1. Symptoms You Will Notice
- Engine may not start or start intermittently
- Transmission may not shift out of park
- Check Engine Light illuminated
- Park lock malfunction or stuck in park
2. Most Common Causes
- Faulty or worn park/neutral position switch 'B'
- High resistance or corroded connectors in the sensor circuit wiring
- Short to ground in the sensor wiring
- Loose or disconnected sensor harness connector
- Worn or damaged transmission shift mechanism
- Internal transmission control module (TCM) failure
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Inspect the park position sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's resistance and voltage output per manufacturer specifications.
Step 4: Check battery voltage and charging system to ensure proper power supply.
Step 5: If sensor and wiring are OK, replace the park position sensor/switch.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The vehicle may not start or could unexpectedly shift out of park, posing a safety risk. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and shop rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.