What it means
The Park input circuit has an electrical fault, so the controller may not receive a reliable Park signal.
At a glance
- Usually lights the check-engine light
How it works
The Park input tells the control module that the selector or transmission is in Park. The module monitors this electrical input and sets P081C when the signal circuit is faulty, so it may not reliably recognize Park even if the selector appears to be there.
Common causes
Most likely first.
- Open circuit in Park input wiring
- Short to ground or power in the input circuit
- Loose or corroded connector
- Faulty Park switch or sensor
- Control module circuit fault
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and scan for related range or transmission codes to see when the Park input fault occurred.
- Watch the Park input and transmission range on a scan tool while moving the selector through its positions, and compare the readings with the actual selector position.
- Inspect the Park switch or sensor connector and harness for looseness, corrosion, damaged insulation, or backed-out pins.
- Use the wiring diagram to test the Park input for an open or short to ground or power and check terminal contact quality.
- If wiring passes, test the Park switch or sensor and then the control-module input using the manufacturer's procedure.
Common fixes
- Reconnect a loose Park input connector and secure it.
- Clean or replace corroded or damaged terminals.
- Repair an open or shorted section of Park input wiring.
- Replace a Park switch or sensor that fails its test.
- Repair or replace a control module only after confirming its input is faulty.
Can I keep driving?
The vehicle may not recognize Park consistently, which can affect starting or shifting depending on its design. Set the parking brake and make sure the vehicle is secure whenever parked; do not rely on the selector indication alone if the vehicle can move.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.