P2548Torque Management Request Input Signal B
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2548 is the general fault on a second torque request channel, B, used when a further module besides the transmission may ask the engine for less or more torque. GM spells out who sits on channel B: in the ECM part of its 2017 table 17OBDG04 and again in 19OBDG03A, P2548 checks the traction torque and speed request coming from the electronic brake and traction control module. A failure is counted when the message's two's-complement protection value does not match, at least 10 of 20 samples, or when the rolling counter fails to step up, at least 6 of 10. The test runs with run/crank active for over 0.5 s, ignition above 6.41 V and no lost-communication code U0121; GM rates it Type B, two trips. Traction or stability intervention via the engine may then be limited. P2549 to P2551 are its narrower faults.
- What you may notice
- Check engine light after two trips (GM Type B)
- Traction or stability control warning lamp
- Reduced traction intervention on slippery roads
- Likely causes
- LikelyData bus disturbance between brake module and engine module
- PossibleBrake/traction control module sends corrupted messages
- RareWeak battery or poor module power supply
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.