P0855 Fault Code

Drive Switch Input Circuit High

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0855 fault code indicates a problem with the Drive Switch Input Circuit. This circuit is responsible for monitoring the drive mode of the vehicle, usually related to the gear selector or transmission position. When this circuit registers a high voltage when it shouldn’t, it triggers the P0855 code.

What are the symptoms of the P0855 code?

Drivers may experience the following symptoms when the P0855 fault code is present:

• The vehicle may not shift properly or may become stuck in a specific gear.
• Dashboard warning lights may illuminate, including the check engine light.
• Erratic transmission behavior, potentially leading to decreased fuel efficiency.
• Difficulty engaging or disengaging the gear selector.

What causes the P0855 code?

Several issues can lead to this fault code, including:

• Faulty transmission range sensor that inaccurately detects the position of the gear selector.
• Damaged or shorted wiring in the drive switch input circuit.
• Poor electrical connections or corrosion in the circuit connections.
• A malfunctioning Engine Control Module (ECM) that misinterprets the drive switch signals.

How to fix P0855?

To resolve the P0855 fault code, the following steps are recommended:

• Inspect the wiring and connectors related to the drive switch input circuit for damage or corrosion, and repair or replace as necessary.
• Test the transmission range sensor for proper function and replace if defective.
• Clear the fault codes from the ECM and test drive the vehicle to see if the code reappears.
• If the problem persists, consider checking the ECM for faults or updates.