AutoCodes – GMC – P2641 GMC

P2641 GMC Code - Torque Management Feedback Signal 'B'

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: P2641 GMC indicates Torque Management Feedback Signal 'B'.
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.

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Code Popularity 1,277

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jan 23, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2641 GMC Description

To improve shift feel, the Transmission Control Module (TCM) may request that the Engine Control Module (ECM) reduce engine torque during shift events. When such a request is received, the ECM responds by retarding the base ignition timing and notifying the TCM that the request has succeeded. If the ECM is unable to comply with the request, the ECM sends the TCM a message that the request has failed.
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.

OBDII Code P2641 GMC - Torque Management Feedback Signal 'B' - AutoCodes.com — P2641 GMC Code - Torque Management Feedback Signal 'B'

What does this mean?

What are the Possible Causes of the DTC P2641 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 P2641 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 P2641 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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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 P2641 GMC Code

1. What are the common symptoms of OBDII code P2641 GMC?

- Common symptoms include rough idling, reduced engine power, and illumination of the Check Engine Light.

2. What does the Torque Management Feedback Signal 'B' refer to in relation to code P2641 GMC?

- The Torque Management Feedback Signal 'B' is a component of the engine control module (ECM) system that monitors torque delivery.

3. What are the possible causes of OBDII code P2641 GMC?

- Potential causes include a faulty torque management feedback signal 'B' sensor, wiring issues, or a malfunctioning ECM.

4. How can I diagnose the issue associated with code P2641 GMC?

- Diagnosing the problem involves using a scan tool to retrieve the fault code, checking the wiring connections, and testing the torque management feedback sensor.

5. Can I continue driving my vehicle with OBDII code P2641 GMC?

- It is not recommended to continue driving the vehicle with this code present, as it can lead to further engine damage or performance issues.

6. How can I repair OBDII code P2641 GMC?

- Repairing the issue involves replacing the faulty torque management feedback sensor, repairing any damaged wiring, or reprogramming the ECM if necessary.

7. Will resetting the Check Engine Light resolve code P2641 GMC?

- Resetting the Check Engine Light may temporarily remove the warning, but the underlying issue causing the code will still need to be addressed.

8. Are there any DIY fixes for OBDII code P2641 GMC?

- DIY fixes may include checking and cleaning the sensor connections, but for a proper repair, it is recommended to consult a professional mechanic.

9. How much does it typically cost to repair OBDII code P2641 GMC?

- The cost of repair can vary depending on the extent of the issue, but it may range from $100 to $300 for parts and labor.

10. Can code P2641 GMC affect the overall performance of the vehicle?

- Yes, this code can impact the engine's performance, leading to issues such as decreased power, poor fuel efficiency, and potential drivability problems.