P2548 code meaning
Torque Management Request Input Signal B
Powertrain system Generic code P25xx codes Check engine light
What P2548 means
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.
P2548 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P2548
- Check engine light after two trips (GM Type B)
- Traction or stability control warning lamp
- Reduced traction intervention on slippery roads
Common causes of P2548
- Most likelyData bus disturbance between brake module and engine module
- PossibleBrake/traction control module sends corrupted messages
- Less likelyWeak battery or poor module power supply
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Torque management input bABS module
What each part of P2548 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 48 | The exact fault in that area. |
What to do next
- Note P2548 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2548
What does P2548 mean?
P2548 means "Torque Management Request Input Signal B". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2548?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2548 fail an emissions test?
Yes, it can. P2548 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2548 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2548 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.