P0861 Fault Code

Gear Shift Module Communication Circuit Low

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

The P0861 fault code indicates an issue within the gear shift module communication circuit, which is responsible for relaying information between the transmission control module and the gear shift assembly. This communication is crucial for the proper functioning of the vehicle's transmission system.

What are the symptoms of the P0861 code?

Symptoms of a P0861 code may manifest as:

• Transmission not shifting properly or erratically.
• Warning lights illuminated on the dashboard, particularly the check engine light.
• Delay or failure in shifting into specific gears.
• Unusual noises coming from the transmission area during shifts.

What causes the P0861 code?

The primary causes of a P0861 fault code can include:

• Damaged wiring or connectors in the gear shift module circuit.
• Faulty gear shift module itself.
• Poor electrical connections leading to intermittent communication failures.
• Issues with the transmission control module (TCM) that affect overall communication.

How to fix P0861?

To address a P0861 fault code, the following steps should be taken:

• Inspect the wiring and connectors for signs of damage, corrosion, or loose connections, and repair as needed.
• Test the gear shift module for proper operation, and replace if found faulty.
• Check the transmission control module and update or reprogram it if necessary.
• Clear the fault codes and test drive the vehicle to ensure the code does not reappear.