P1704: Digital TRS Failed to Transition State
The P1704 code indicates that the Transmission Range Sensor (TRS), also known as the digital transmission range sensor, has failed to transition between states (e.g., Park, Reverse, Neutral, Drive) as expected by the Powertrain Control Module (PCM). This sensor communicates the gear selector position to the PCM. A failure to transition can cause incorrect gear selection, starting issues, or transmission performance problems. Common causes include a faulty TRS, wiring issues, or a misadjusted shift linkage.
1. Symptoms You Will Notice
- Engine starts in any gear or fails to start
- Transmission stuck in one gear or erratic shifting
- Check Engine Light illuminated
- Incorrect gear indicator on dashboard
2. Most Common Causes
- Faulty or stuck turbocharger relief control solenoid
- Short or open circuit in the solenoid wiring
- Corroded or bent pins in the electrical connector
- Defective wastegate actuator
- Disconnected, damaged, or leaking vacuum or pressure hoses
- Faulty turbocharger pressure sensor (MAP/boost sensor)
- Failed PCM (rare but possible)
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm P1704 and check for other codes.
Step 2: Inspect the TRS connector and wiring for damage, corrosion, or loose connections.
Step 3: Test the TRS signal voltage with a multimeter while moving the gear selector through all positions.
Step 4: Check shift linkage adjustment and ensure proper mechanical operation.
Step 5: If all else is okay, replace the digital TRS and clear codes.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The vehicle may start in gear or shift unexpectedly, 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 vehicle and shop rates.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.