P2551
Torque Management Request Input Signal B High
Torque management input B reads stuck high — short to reference voltage or message at maximum. ECM rejects the request to avoid unintended high-torque commands.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to reference voltageCommon
Parts involved
- Torque Management Input B
P2551 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.