P2549 code meaning
Torque Management Request Input Signal B Range/Performance
Powertrain system Generic code P25xx codes Check engine light
What P2549 means
P2549 covers a torque request on channel B that arrives readable but makes no sense: a requested torque outside the expected band, a request that contradicts the current driving state, or one that changes in a way the sender could not plausibly mean. The wiring or bus link is assumed intact here, which separates it from the general fault P2548. No maker documents P2549 publicly. In GM's 2017 engine tables channel B carries the intervention wish of the brake/traction module, which GM validates under P2548 only. CARB obliges makers to check input components for rational values when they matter for emissions or for other monitors. The equivalent code on channel A is P2545; P2550 and P2551 are the low and high faults on B. Traction control may act less smoothly.
P2549 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2549
- Check engine light depending on make
- Traction control intervenes abruptly or not at all
Common causes of P2549
- Most likelyRequesting module (e.g. brake/traction module) computes implausible values
- PossibleSoftware levels of sender and engine module do not match
- Less likelyFaulty input data at the requesting module, such as wheel speed
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 P2549 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. |
| 49 | The exact fault in that area. |
What to do next
- Note P2549 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 P2549
What does P2549 mean?
P2549 means "Torque Management Request Input Signal B Range/Performance". P2549 covers a torque request on channel B that arrives readable but makes no sense: a requested torque outside the expected band, a request that contradicts the current driving state, or one that changes in a way the sender could not plausibly mean. It is a generic code, so it means the same on every make.
Is it safe to drive with P2549?
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 P2549 fail an emissions test?
Yes, it can. P2549 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 P2549 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2549 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.