P0908: Gate Select Position Circuit Intermittent
The P0908 code indicates an intermittent fault in the gate select position circuit, which is part of the transmission range sensor system. This sensor tells the transmission control module (TCM) which gear the driver has selected (e.g., Park, Reverse, Neutral, Drive). An intermittent signal can cause erratic shifting, failure to start, or incorrect gear engagement. Common causes include a faulty transmission range sensor, damaged wiring or connectors, or corrosion in the circuit.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Intermittent starting issues (engine may not start in Park or Neutral)
- Erratic or harsh shifting
- Transmission stuck in one gear or fails to shift
- Incorrect gear display on dashboard
2. Most Common Causes
- Faulty transmission range sensor (gate select position sensor)
- Damaged, corroded, or loose wiring/connectors in the sensor circuit
- Intermittent short or open in the circuit
- Failed TCM (rare)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to confirm P0908 and check for related codes.
Step 2: Visually inspect the transmission range sensor connector and wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's resistance and voltage output per manufacturer specifications using a multimeter.
Step 4: If sensor tests OK, check for intermittent shorts or opens by wiggling the wiring harness while monitoring the sensor signal.
Step 5: Replace the transmission range sensor if faulty; otherwise, repair wiring or replace the TCM as needed.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. An intermittent circuit can cause sudden loss of gear selection or starting ability, leading to unsafe driving conditions.
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 $150-$400.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.