P0881 TCM Power Input Signal Range/Performance

The TCM power input codes watch the supply voltage of the gearbox module or of its solenoid supply. Without a proper supply all solenoids go dead and the gearbox falls back to its hydraulic emergency gear with maximum line pressure: a fixed gear, harsh engagement, no shifting. Ford's external gearbox modules check a window of 9 to 16 V; GM reports the same under P0562/P0563. P0881 means the supply is electrically within range but implausible, for example differing from the engine module's system voltage or dipping when the solenoids switch on. No maker publishes a strategy for it.

Likely causes

Symptoms

• MIL on
• Occasional harsh shifts
• Limp mode possible

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, newtonnet.co.uk.