Powertrain, generic (extended)

P2549 Torque Management Request Input Signal B Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Requesting module (e.g. brake/traction module) computes implausible values
Software levels of sender and engine module do not match
Faulty input data at the requesting module, such as wheel speed

Symptoms

  • Check engine light depending on make
  • Traction control intervenes abruptly or not at all

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

torque management input babs module

Related codes

P2548P2550P2551P2545

References: law.cornell.edu, gsi.ext.gm.com.