Damaged or chafed wiring in the torque management request input signal circuit, causing a short to ground; Corroded, loose, or disconnected electrical connector at the torque management sensor or PCM; Failed torque management request sensor or switch internal short; Faulty PCM driver circuit for the signal input; Aftermarket electronic accessories improperly tapped into the signal circuit; Water intrusion into a connector or sensor housing causing a low-resistance path to ground

DTC codes / P25xx · Vehicle speed, idle control and auxiliary inputs / P2546

P2546Torque Management Request Input Signal 'A' Low

Q: What does code P2546 mean?

Torque Management Request Input Signal 'A' Low. P2546 means the powertrain control module (PCM) has detected that the torque management request input signal 'A' circuit is reporting a voltage lower than the expected range. This signal is used by the PCM to coordinate torque reduction requests from systems such as the transmission controller or stability control, and a low voltage indicates a short to ground, an open circuit, or a faulty sensor.

P2546 means the powertrain control module (PCM) has detected that the torque management request input signal 'A' circuit is reporting a voltage lower than the expected range. This signal is used by the PCM to coordinate torque reduction requests from systems such as the transmission controller or stability control, and a low voltage indicates a short to ground, an open circuit, or a faulty sensor.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

Illumination of the check engine light (malfunction indicator lamp) with no other noticeable symptoms
Harsh or delayed transmission shifts as torque management intervention is disabled
Reduced engine power or a limp-home mode in some vehicles
Inconsistent cruise control operation or disabled cruise control
Traction control or stability control warning light illuminated on the dashboard

Common causes, most likely first

Damaged or chafed wiring in the torque management request input signal circuit, causing a short to ground
Corroded, loose, or disconnected electrical connector at the torque management sensor or PCM
Failed torque management request sensor or switch internal short
Faulty PCM driver circuit for the signal input
Aftermarket electronic accessories improperly tapped into the signal circuit
Water intrusion into a connector or sensor housing causing a low-resistance path to ground

How to diagnose and fix it

Connect a scan tool and record all stored codes and freeze-frame data to confirm P2546 is the primary fault and not a secondary code.
Visually inspect the torque management sensor and its connector for corrosion, water intrusion, or loose pins, and clean or repair as needed.
Disconnect the sensor and check the signal circuit voltage at the connector with the key on; a low voltage with the sensor disconnected points to a wiring short to ground.
Perform a continuity test from the sensor connector to the PCM connector to check for an open circuit or excessive resistance.
Check for continuity between the signal circuit and ground with the sensor and PCM disconnected; any continuity indicates a short to ground that must be repaired.
If the wiring and connectors are good, substitute a known-good torque management sensor and clear the code to see if it returns.
If the code persists after sensor replacement, test the PCM input circuit with a breakout box and replace the PCM only if the internal driver is confirmed faulty.

Before you replace the torque management sensor

A low signal voltage often comes from a chafed wire harness near the transmission or pedal assembly rather than a failed sensor, so always perform a wiggle test on the harness while monitoring live data.
The torque management request input is frequently a shared signal with the electronic throttle control or stability control system, and a fault in those systems can set P2546 as a companion code.
Aftermarket remote starters or alarm systems that tap into the pedal or throttle wiring are a common cause of a short to ground on this circuit that is missed during diagnosis.
Some vehicles will not set a drivability symptom because the PCM defaults to a fixed torque management strategy, so the only clue is the stored code and freeze-frame data.
A battery that has been disconnected or a PCM reflash can cause a temporary P2546 that clears after a few drive cycles, so always check for a history of recent electrical work before condemning parts.

Can I keep driving with P2546?

You can usually continue driving with P2546 because the PCM defaults to a safe torque management strategy, but avoid towing or aggressive acceleration until the fault is repaired. If the vehicle enters limp-home mode or the transmission shifts harshly, have it diagnosed promptly to prevent further damage.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.