P2551 GMC Code - Torque Management Request Input Signal 'B' High
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
- P2551 GMC indicates Torque Management Request Input Signal 'B' High.
- 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 P2551 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 P2551 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 P2551 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 P2551 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 P2551 GMC Code
1. What are the common symptoms of OBDII code P2551 GMC?
The common symptoms of OBDII code P2551 GMC include reduced engine power, illuminated Check Engine Light (CEL), and potential difficulty accelerating.
2. What does the OBDII code P2551 GMC indicate?
OBDII code P2551 GMC indicates a Torque Management Request Input Signal 'B' High, which means that the signal sent to the Engine Control Module (ECM) is higher than expected.
3. What are the possible causes of OBDII code P2551 GMC?
Possible causes of OBDII code P2551 GMC include a faulty accelerator pedal position sensor, issues with the throttle body, wiring problems, or a malfunctioning ECM.
4. How can I diagnose OBDII code P2551 GMC?
Diagnosing OBDII code P2551 GMC involves using a scan tool to read the fault codes, checking the wiring and connectors related to the accelerator pedal position sensor, and testing the sensor's functionality.
5. Can I still drive my vehicle with OBDII code P2551 GMC?
It is not recommended to drive your vehicle with OBDII code P2551 GMC, as it can lead to reduced engine power and potentially unsafe driving conditions. It is best to address the issue promptly.
6. How can I repair OBDII code P2551 GMC?
Repairing OBDII code P2551 GMC may involve replacing the faulty accelerator pedal position sensor, repairing any wiring issues, or addressing problems with the throttle body. Consult with a professional mechanic for an accurate diagnosis and repair.
7. Will resetting the ECM clear OBDII code P2551 GMC?
Resetting the ECM may temporarily clear the code, but if the underlying issue causing OBDII code P2551 GMC is not addressed, the code is likely to reappear. It is important to diagnose and fix the root cause of the problem.
8. Is OBDII code P2551 GMC a serious issue?
OBDII code P2551 GMC should be taken seriously as it can affect the performance and drivability of your vehicle. Ignoring the code may lead to further damage or safety concerns, so it is best to address it promptly.
9. Can extreme weather conditions trigger OBDII code P2551 GMC?
Extreme weather conditions can potentially affect the components related to OBDII code P2551 GMC, such as wiring or sensors. It is important to keep your vehicle well-maintained to prevent weather-related issues.
10. How much does it cost to fix OBDII code P2551 GMC?
The cost to fix OBDII code P2551 GMC can vary depending on the specific cause of the issue, the labor rates in your area, and the parts needed for repair. It is recommended to obtain a diagnosis from a professional mechanic to determine the exact cost.
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