Gear Shift Position Circuit Intermittent
The P0918 code indicates an intermittent fault in the gear shift position circuit, which monitors the position of the gear selector (PRNDL). This circuit uses sensors or switches to send the selected gear position to the transmission control module (TCM) or powertrain control module (PCM). An intermittent signal can cause erratic shifting, failure to start, or incorrect gear display. Common causes include a faulty range sensor, damaged wiring, loose connectors, or a failing TCM/PCM.
01. Most Common Causes
- Faulty transmission range sensor (TRS)
- Damaged or corroded wiring/connectors in the shift position circuit
- Loose or intermittent electrical connections
- Failing transmission control module (TCM) or powertrain control module (PCM)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic or no gear shift display on dashboard
- Engine may not start or only starts in certain gear positions
- Transmission stuck in limp mode or fails to shift properly
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm code P0918 and check for related codes.
Step 2: Visually inspect the transmission range sensor and wiring harness for damage, corrosion, or loose connections.
Step 3: Test the range sensor resistance and voltage per manufacturer specifications using a multimeter.
Step 4: Check for intermittent faults by wiggling wiring harness while monitoring sensor signal with a scan tool.
Step 5: If all else is fine, test the TCM/PCM for proper operation or update software.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The vehicle may experience erratic shifting or fail to start, which can be dangerous. Have it diagnosed promptly.
How much does it cost to fix?▼
Typical repair costs range from $50 to $150 for parts like a range sensor, plus labor. Diagnostic fees may apply.