P2639 GMC Code - Torque Management Feedback Signal 'A' Low
Quick Answer
To improve shift feel, the Transmission Control Module (TCM) may request that the Engine Control Module (ECM) reduce engine torque during shift events. Common causes include Faulty Engine Control Module (ECM), Faulty Transmission Control Module (TCM), Engine Control Module (ECM) software update. 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
- P2639 GMC indicates Torque Management Feedback Signal 'A' Low.
- Common causes
- Common causes include Faulty Engine Control Module (ECM), Faulty Transmission Control Module (TCM), Engine Control Module (ECM) software update.
- 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.
Code P2639 GMC Description
The torque reduction request is sent to the ECM through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM.
A fault in the CAN will not cause the ECM to set the Diagnostic Trouble Codes (DTC). If a CAN fault occurs, other DTCs will set before this code.
The ECM set the OBDII code when the TCM receives a torque reduction failure message from the ECM.
What are the Possible Causes of the DTC P2639 GMC?
- Faulty Engine Control Module (ECM)
- Faulty Transmission Control Module (TCM)
- Engine Control Module (ECM) software update
- Transmission Control Module (TCM) software update
- Engine Control Module (ECM) harness is open or shorted
- Engine Control Module (ECM) circuit poor electrical connection
How to Fix the DTC P2639 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P2639 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P2639 GMC Code
1. What are the common symptoms of OBDII code P2639 GMC?
The common symptoms of code P2639 include reduced engine performance, engine stalling, rough idling, and the illumination of the Check Engine Light.
2. What are the possible causes of OBDII code P2639 GMC?
Possible causes of code P2639 include issues with the torque management system, faulty torque sensor, damaged wiring or connectors related to the torque management system, or a malfunctioning Engine Control Module (ECM).
3. How can I diagnose OBDII code P2639 GMC?
Diagnosing code P2639 typically involves using a diagnostic scanner to retrieve the code, inspecting the torque sensor and related components for damage, and testing the wiring and connectors for continuity and proper connections.
4. Can I continue driving my vehicle with OBDII code P2639 GMC?
It is not recommended to continue driving your vehicle with code P2639 present, as it can lead to further damage to the engine or transmission. It is best to address the issue promptly to avoid potential safety hazards.
5. How can I repair OBDII code P2639 GMC?
Repairing code P2639 may involve replacing the torque sensor, repairing or replacing damaged wiring or connectors, or reprogramming the ECM to address any software-related issues causing the code.
6. Is it possible to clear OBDII code P2639 GMC without fixing the underlying issue?
Clearing the code without addressing the underlying issue may temporarily turn off the Check Engine Light, but the problem will likely resurface. It is essential to fix the root cause of the code to prevent further issues.
7. How much does it typically cost to repair OBDII code P2639 GMC?
The cost of repairing code P2639 can vary depending on the specific cause of the issue, the labor rates in your area, and whether you choose to address the problem yourself or take your vehicle to a professional mechanic. Costs may range from a few hundred dollars to over a thousand dollars.
8. Can a DIY enthusiast fix OBDII code P2639 GMC at home?
Depending on your mechanical skills and access to tools, it may be possible to address code P2639 at home. However, due to the complexity of the torque management system, it is recommended to have some experience working on vehicles before attempting a DIY repair.
9. Will OBDII code P2639 GMC cause my vehicle to fail an emissions test?
Yes, code P2639 can cause your vehicle to fail an emissions test, as it indicates a problem with the torque management system that can affect engine performance and emissions. It is important to address the issue before undergoing an emissions test.
10. How long does it take to repair OBDII code P2639 GMC?
The repair time for code P2639 can vary depending on the specific cause of the issue, the availability of parts, and whether you are performing the repair yourself or taking your vehicle to a professional. Repairs may take anywhere from a few hours to a full day.
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