Engine-CodesGMC – P1685 GMC

P1685 GMC Code - Transmission Control Module Power Up Temperature Sensor Circuit Low Voltage

Quick Answer

The P1685 GMC code indicates a problem with the Transmission Control Module (TCM) Power Up Temperature Sensor Circuit, specifically detecting low voltage. Common causes include Faulty Power Up Temperature Sensor, Damaged wiring or connectors in the sensor circuit, Corrosion in the sensor circuit. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P1685 GMC indicates Transmission Control Module Power Up Temperature Sensor Circuit Low Voltage.
Common causes
Common causes include Faulty Power Up Temperature Sensor, Damaged wiring or connectors in the sensor circuit, Corrosion in the sensor circuit.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Aug 25, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P1685 GMC Description

The P1685 GMC code indicates a problem with the Transmission Control Module (TCM) Power Up Temperature Sensor Circuit, specifically detecting low voltage. The TCM is responsible for controlling the transmission functions in the vehicle, such as gear shifting and torque converter lockup. The Power Up Temperature Sensor is used to monitor the temperature of the transmission fluid when the TCM is powered up. A low voltage reading from this sensor can indicate issues with the sensor itself or a problem with the circuit that transmits the sensor's signal to the TCM.

OBDII Code P1685 GMC - Transmission Control Module Power Up Temperature Sensor Circuit Low Voltage
P1685 GMC Code - Transmission Control Module Power Up Temperature Sensor Circuit Low Voltage

Common Causes of P1685 GMC

  1. Faulty Power Up Temperature Sensor
  2. Damaged wiring or connectors in the sensor circuit
  3. Corrosion in the sensor circuit
  4. TCM malfunction
  5. Low transmission fluid level or poor quality fluid

Symptoms of P1685 GMC

  1. Rough or delayed shifting
  2. Transmission slipping
  3. Limp mode activation
  4. Check Engine Light illuminated
  5. Poor fuel efficiency

How to Fix P1685 GMC

  1. Perform a visual inspection of the sensor circuit, wiring, and connectors for any damage or corrosion.
  2. Test the Power Up Temperature Sensor using a multimeter to check for proper voltage readings.
  3. Replace the sensor if it is found to be faulty.
  4. Clear the diagnostic trouble codes from the TCM memory and reset the system.
  5. Test drive the vehicle to ensure the issue has been resolved and the code does not reappear.

Cost to Fix P1685 GMC

The cost of repairing a P1685 GMC code can vary depending on the specific cause of the issue. Typically, replacing the Power Up Temperature Sensor can range from $50 to $150, while diagnosing and repairing wiring or connector issues may increase the cost. Including parts and labor, the total repair cost could range from $100 to $300. It's advisable to consult with a trusted mechanic or auto repair shop for a more accurate estimate based on your vehicle's make and model.

Need more information about the P1685 GMC code?

Need more information on how to fix the P1685 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1685 GMC code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1685 GMC Code

No Frequently Asked Questions about P1685 GMC Code found.

Discuss the causes and fixes for P1685 GMC OBDII Code

Code P1685 GMC comments

No comments found for this page.