P1702: TRS Sensor Intermittent Circuit Malfunction
The P1702 code indicates an intermittent electrical fault in the Transmission Range Sensor (TRS) circuit, also known as the neutral safety switch or park/neutral position switch. This sensor tells the PCM what gear the transmission is in. An intermittent circuit malfunction means the signal is cutting in and out, often due to a loose connection, corroded wiring, or a failing sensor. This can cause incorrect gear readings, leading to shifting issues or no-start conditions.
01. Most Common Causes
- Faulty transmission range sensor
- Corroded or loose electrical connector at the sensor
- Damaged wiring or short circuit in the TRS circuit
- Intermittent open or ground in the sensor circuit
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Transmission stuck in limp mode or fails to shift properly
- Engine may not start or starts only in neutral or park
- Incorrect gear indication on the dashboard
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to confirm P1702.
Step 2: Visually inspect the TRS connector and wiring for damage, corrosion, or loose pins.
Step 3: Test the TRS sensor resistance and continuity per manufacturer specs using a multimeter.
Step 4: Check for intermittent faults by wiggling the harness while monitoring sensor signal with a scan tool.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The transmission may shift erratically or get stuck in limp mode, and the vehicle may not start. Have it diagnosed promptly.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor, depending on whether the sensor or wiring needs replacement.