Transmission Park Position Sensor Circuit Low
The P07B3 code indicates that the transmission park position sensor or its circuit is reporting a voltage lower than expected. This sensor tells the powertrain control module (PCM) when the transmission is in Park. A low circuit condition can be caused by a faulty sensor, damaged wiring, poor electrical connections, or a short to ground. This may prevent the engine from starting or cause incorrect gear selection.
1. Symptoms You Will Notice
- Engine may not start or cranks but won't start
- Transmission stuck in Park or fails to shift out of Park
- Check Engine Light illuminated
- Incorrect gear indicator on dashboard
2. Most Common Causes
- Faulty park position sensor
- Damaged or corroded wiring/connectors
- Short to ground in the sensor circuit
- Low battery voltage or charging system issue
3. Step-by-Step Diagnosis
Step 1: Scan for additional codes and verify P07B3 is present.
Step 2: Visually inspect the park position sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Using a multimeter, check the sensor signal voltage at the PCM connector; should be near 5V or battery voltage depending on design. Low voltage indicates a short or faulty sensor.
Step 4: Test the sensor resistance per manufacturer specs; replace if out of range.
Step 5: Check for shorts to ground by disconnecting the sensor and measuring resistance between signal wire and ground; should be infinite.
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?▼
Typically between $50 and $150 for parts and labor, depending on the cause. A sensor replacement is usually under $100, while wiring repairs may cost more.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.