P2548: Torque Management Request Input Signal B

What it means

A fault is detected in torque management request input signal B. The code does not identify the requesting module or signal implementation.

At a glance

• Usually lights the check-engine light

How it works

Torque management request input signal B lets the powertrain control module receive a request to adjust engine torque from another control or input device. P2548 indicates a fault with signal B, but does not specify whether the problem is an open, a short, a faulty input, or a problem in the module sending the request.

Common causes

Most likely first.

1. Open, shorted, or damaged signal wiring
2. Loose or corroded connector
3. Faulty torque request switch or sensor
4. Fault in the module sending the request

Symptoms

• Check-engine light
• Reduced or inconsistent engine power
• Altered transmission shifting

How to diagnose it

1. Record freeze-frame data and check live data for torque management request signal B for missing, fixed, or implausible readings.
2. Scan for related codes in the powertrain or requesting module to identify whether the fault is shared with other signals or communications.
3. Inspect signal B wiring and connectors for breaks, shorts, loose pins, corrosion, or water entry.
4. Use the wiring diagram to test signal B continuity and check for shorts to ground or power, comparing results with the manufacturer's specification.
5. If wiring tests pass, check the torque request switch or sensor and then verify the sending module's inputs and output.

Common fixes

• Reconnect or clean a loose or corroded signal B connector.
• Repair open, shorted, or damaged signal B wiring.
• Replace a faulty torque request switch or sensor if its output fails testing.
• Repair or replace the sending module only after its wiring and inputs are verified.

Can I keep driving?

You may be able to drive cautiously if power and shifting are consistent, but avoid towing or demanding acceleration until the request fault is diagnosed. Stop if engine power becomes unpredictable or shifting becomes unsafe.