P0880: TCM Power Input Signal

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. P0880 is the general fault. Hyundai's 2017–19 six-speed automatics set it when the solenoid supply drops below 7 V or rises above 22 V: MIL on, limp mode in 4th gear. Hyundai's bulletin points to the valve body harness and the TCU fuses and expressly not to the gearbox.

Medium severity. Can I keep driving?It depends on the symptoms. If the car is running normally you can go to a repair shop; if it goes into limp mode, drive as little as possible.

Symptoms

MIL on
Limp mode in a fixed gear, no shifting
Harsh engagement into D or R

Most likely causes

Harness or connector between module and valve body damaged or corroded
TCU fuse or transmission relay faulty
Weak battery, charging fault, poor ground
Gearbox module faulty

What to check, in order

Start with the simplest. You can tick off each step.

Check the battery and grounds
Clear the code and see if it returns
If it is a reference voltage code, disconnect sensors one at a time and see if the voltage recovers
Check whether a software update is available
Do not replace the control module without a full diagnosis

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P0880 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
8: Transmission
80: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0880?

It depends on the symptoms. If the car is running normally you can go to a repair shop; if it goes into limp mode, drive as little as possible.

What causes code P0880?

The most common causes are: harness or connector between module and valve body damaged or corroded; tCU fuse or transmission relay faulty; weak battery, charging fault, poor ground.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.