P2642
Torque Management Feedback Signal B Range/Performance
Transmission / torque management
Generic OBD-II
Medium
What it means
P2642 means the torque-management feedback signal 'B' — used to coordinate engine torque with the transmission during shifts — is out of its expected range or not tracking correctly. The usual result is rough or poorly-timed shifting rather than a no-start. It's worth diagnosing promptly so the mismatched torque control doesn't wear the transmission.
Medium
Can I keep driving? Usually drivable, but you may notice harsh or poorly-timed shifts. Get it diagnosed before it strains the transmission.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh or abrupt shifts
- Shift shock or flare during gear changes
- Possible reduced power or limp mode
Common causes
Most likely first
- Low or dirty transmission fluidLikely
- Faulty torque-management or shift-related solenoidCommon
- Open, shorted, or corroded wiring in the feedback circuitCommon
- Poor electrical connection at the transmission connectorLess often
- Faulty PCM/TCMLess often
How to diagnose & fix
Work through it in order
- Check transmission fluid level and condition first.
- Scan for companion torque-management codes (P2640–P2644).
- Inspect the transmission wiring harness and connectors for damage.
- Test the related solenoids and their circuits.
- If wiring and solenoids check out, suspect the control module. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2642?+
Short-term, yes, but harsh shifting adds wear. Diagnose it soon to avoid transmission damage.
Can I just clear P2642?+
It comes back until the underlying fault is fixed. Address the fluid, wiring, or solenoid first.
Related codes
Often seen with P2642
Read & clear P2642 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