P2550
Torque Management Request Input Signal B Low
Torque management
Generic OBD-II
Medium
What it means
P2550 means the 'B' torque-management request signal into the engine computer is reading low. Modules such as the transmission controller send this signal to ask the ECU to trim engine torque during shifts; a low or shorted signal usually points to wiring, a connector, or the sending module, and can show up as reduced power or rough shifting.
Medium
Can I keep driving? Often drivable, but the ECU may cut power or the transmission may shift oddly, and some vehicles drop into limp mode when this signal is wrong.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or limp mode
- Harsh, delayed, or unusual shifting
- Hesitation when the ECU adjusts torque
Common causes
Most likely first
- Short to ground or low signal in the torque-request 'B' circuitLikely
- Corroded or loose connector between the requesting module and the ECMCommon
- Faulty transmission control module or other module sending the requestCommon
- Faulty ECM inputLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and check for companion transmission or module codes that share the circuit.
- Inspect the torque-request wiring and connectors for a short to ground or corrosion.
- Compare the live torque-request signal against expected values during a drive.
- Verify the sending module (often the TCM) is powered and communicating correctly.
- Repair the wiring or replace the faulty module, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2550?+
Short trips are usually possible, but expect reduced power or odd shifting, and some vehicles limp. Get it diagnosed before it strands you or masks a transmission fault.
Can I just clear P2550?+
It returns while the circuit or sending module is faulty. Clearing only confirms whether the fault is still active.
Related codes
Often seen with P2550
Read & clear P2550 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX