P0881
TCM Power Input Signal Range/Performance
Transmission / control module power
Generic OBD-II
Medium
What it means
P0881 means the transmission control module (TCM) is seeing an implausible or unstable voltage on its power input — the feed that keeps the module running. Note this is the transmission control module, not traction control. With an unsteady supply the TCM can shift improperly or default to limp mode; the engine itself still starts and runs.
Medium
Can I keep driving? Engine starts and runs; the transmission may shift improperly or fall into limp mode because the control module's power supply is unstable — repair soon.
Common symptoms
What you'll notice
- Improper shifting, or the transmission won't shift
- Check-engine or transmission warning light on
- Transmission enters limp mode (reduced performance)
- Intermittent transmission faults or dropouts
Common causes
Most likely first
- Loose or corroded TCM power or ground connectionsLikely
- Faulty TCM power relayCommon
- Damaged wiring in the TCM power feedCommon
- Faulty transmission control moduleLess often
How to diagnose & fix
Work through it in order
- Inspect and clean the TCM power and ground connections; poor grounds are a common cause.
- Check battery and charging-system voltage for stability.
- Test the TCM power relay and its control circuit.
- Repair power-feed wiring as needed, then replace the relay or TCM if the supply still can't be stabilized. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0881?+
The engine runs, but the transmission may shift poorly or enter limp mode. Have the power supply and grounds checked soon.
Can I just clear P0881?+
It clears, but returns whenever the supply voltage goes out of range. Fix the connection or relay first.
Related codes
Often seen with P0881
Read & clear P0881 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