P2550 code meaning
Torque Management Request Input Signal B Low
Powertrain system Generic code P25xx codes Check engine light
What P2550 means
P2550 marks the second torque request input, B, as stuck below its lower limit. A hard-wired line would be pulled to ground by chafed insulation or a fault in the sending stage; in a networked design the sender would be reporting a value that lies under the bottom of the defined range. The engine module then disregards input B and keeps running on its own torque calculation. No maker documents P2550 publicly. GM's 2019 table 19OBDG03A assigns the B channel to the traction request of the electronic brake and traction control module, sent in messages $1C8/$237, and checks it only with the general code P2548. CARB requires electronic inputs to be monitored for out-of-range values when they influence emissions. P2551 is the high-side fault, P2546 the low fault on input A.
P2550 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2550
- Check engine light depending on make
- Traction-related torque reduction no longer applied
Common causes of P2550
- PossibleRequest line chafed through and shorted to ground
- PossibleOutput stage of the requesting module defective
- Less likelyCorroded or water-logged connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Torque management input b
What each part of P2550 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. |
| 50 | The exact fault in that area. |
What to do next
- Note P2550 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 P2550
What does P2550 mean?
P2550 means "Torque Management Request Input Signal B Low". P2550 marks the second torque request input, B, as stuck below its lower limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P2550?
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 P2550 fail an emissions test?
Yes, it can. P2550 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 P2550 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2550 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.