Transmission Range Sensor Circuit Low Input
The P0707 code indicates that the Powertrain Control Module (PCM) has detected a low voltage signal from the transmission range sensor (TRS) circuit. This sensor tells the PCM which gear position (Park, Reverse, Neutral, Drive) is selected. A low input means the voltage is below the expected range, often due to a short to ground, faulty sensor, or wiring issues. This can cause incorrect gear selection, harsh shifting, or no start condition.
1. Symptoms You Will Notice
- Check Engine Light on
- Transmission stuck in one gear or limp mode
- Incorrect gear indication on dashboard
- Engine may not start in Park or Neutral
2. Most Common Causes
- Faulty transmission range sensor
- Short to ground in sensor circuit wiring
- Corroded or damaged connector
- Failed PCM (rare)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0707 is present.
Step 2: Inspect transmission range sensor connector for damage, corrosion, or loose pins.
Step 3: Test sensor signal voltage with a multimeter; should be 5V reference and vary with gear position.
Step 4: Check for shorts to ground in the signal wire between sensor and PCM.
Step 5: If wiring and sensor are good, test PCM for proper operation.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The transmission may shift erratically or get stuck in one gear, increasing the risk of an accident or transmission damage.
How much does it cost to fix?▼
Typically $50-$150 for diagnosis and repair, but if the sensor needs replacement, parts and labor can range from $100-$300.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.