AutoCodes – Ford – P2551 Ford

P2551 Ford 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 Ford 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.

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Code Popularity 1,577

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 18, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2551 Ford 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 P2551 Ford - Torque Management Request Input Signal 'B' High - AutoCodes.com — P2551 Ford Code - Torque Management Request Input Signal 'B' High

What does this mean?

What are the Possible Causes of the DTC P2551 Ford?

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 Ford?

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 Ford 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 P2551 Ford Code

1. What does the OBDII code P2551 mean on a Ford vehicle?

The P2551 code indicates that the Torque Management Request Input Signal 'B' is reading a voltage higher than the expected range, suggesting a potential issue with the signal circuit or related components.

2. What are the common symptoms of the P2551 code?

Symptoms may include reduced engine performance, activation of limp mode, poor acceleration, or the illumination of the check engine light.

3. What causes the P2551 code on a Ford vehicle?

Common causes include a faulty torque management request sensor, damaged wiring or connectors, a failing PCM (Powertrain Control Module), or sensor circuit issues.

4. Can I drive my Ford with the P2551 code active?

Driving with the P2551 code is not recommended, as it may lead to reduced performance or further damage to the engine or transmission systems.

5. How do I diagnose the P2551 code?

Start by using an OBDII scanner to confirm the code. Then, inspect wiring and connectors for damage, test the torque management request sensor, and verify the signal voltage with a multimeter.

6. How can I fix the P2551 code on my Ford?

Repairs may involve replacing the torque management request sensor, repairing or replacing damaged wiring, cleaning or reconnecting connectors, or reprogramming or replacing the PCM if necessary.

7. What tools are needed to troubleshoot the P2551 code?

Youâ€™ll need an OBDII scanner, a multimeter to test circuits, and possibly wiring diagrams specific to your Ford model for troubleshooting.

8. Is the P2551 code related to the transmission system?

Yes, the P2551 code can affect the transmission system, as torque management plays a role in transmission operation and shifting.

9. Can a bad battery or alternator cause the P2551 code?

While unlikely, electrical issues from a weak battery or failing alternator can cause voltage irregularities, potentially triggering this code.

10. Does the P2551 code require PCM replacement?

PCM replacement is a last resort and only necessary if all other components and wiring are confirmed to be in good working condition but the code persists.