The transmission control module receives power from the battery through a series of fuses and relays. Obviously, this protects the TCM from the direct voltage, which could easily fry the circuitry. A P0881 means that the ECU has detected a problem within this power circuit.
How Serious is the Code?
The P0881 diagnostic trouble code is relatively serious, because it means that the transmission control module is having a problem powering up.
Symptoms of a P0881 include:
- Harsh or erratic shifting
- Delayed shifting
- The engine may stall
- Shift interlock failure
- Malfunctioning speedometer
- TCM or ECU power relay failure
- Blown or corroded fuse
- Fusible link failure
- Damaged connectors or wiring
- Failing battery
- Failing alternator
How to Diagnose the Code?
When trying to diagnose a P0881 OBDII code, the wiring, connectors, fuses, fusible link(s), and relay(s) should all be checked. In addition, the car battery and alternator may also cause this problem. So those two items should be checked with a volt meter.
What Repairs Will Fix P0881?
- Repair or replace damaged wiring/connectors
- Replace the power relay
- Replace the blown fuse(s)
- Replace the fusible link
- P0880 – TCM Power Input Signal
- P0882 – TCM Power Input Signal Low
- P0883 – TCM Power Input Signal High
- P0884 – TCM Power Input Signal Intermittent