P2546 Code - Torque Management Request Input 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
- P2546 indicates Torque Management Request Input 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 P2546 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 P2546?
- 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 P2546?
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 P2546 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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Information for Specific Makes
- P2546 Buick — Torque Management Request Input Signal 'A' Low
- P2546 Cadillac — Torque Management Request Input Signal 'A' Low
- P2546 Chevrolet — Torque Management Request Input Signal 'A' Low
- P2546 Dodge — Torque Management Request Input Signal 'A' Low
- P2546 Ford — Torque Management Request Input Signal 'A' Low
- P2546 GMC — Torque Management Request Input Signal 'A' Low
- P2546 Lincoln — Torque Management Request Input Signal 'A' Low
- P2546 Mercury — Torque Management Request Input Signal 'A' Low
- P2546 Pontiac — Torque Management Request Input Signal 'A' Low
Frequently Asked Questions about P2546 Code
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