P0815 Fault Code

Upshift Switch Circuit

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

The P0815 fault code indicates a problem with the upshift switch circuit, which is an important component in the vehicle's transmission system. This circuit monitors the upshift switch, which helps to control the shifting of gears automatically or manually, depending on the vehicle's transmission type. The fault usually arises from issues in wiring, the switch itself, or the transmission control module (TCM).

What are the symptoms of the P0815 code?

Symptoms that may accompany the P0815 fault code are:

• The vehicle may exhibit erratic shifting behavior.
• The check engine light may illuminate on the dashboard.
• Manual shifting may become difficult or unresponsive.
• The transmission may be stuck in a particular gear, affecting overall performance.

What causes the P0815 code?

Common causes of the P0815 code include:

• A malfunctioning upshift switch.
• Damaged or corroded wiring in the upshift switch circuit.
• Poor connections in the wiring harness.
• Faulty transmission control module (TCM).
• Issues with the transmission itself that affect the operation of the upshift switch.

How to fix P0815?

To resolve the P0815 code, the following steps are recommended:

• Inspect the wiring and connectors associated with the upshift switch for damage or corrosion.
• Test the upshift switch to ensure it is functioning properly and replace it if necessary.
• Clear the trouble codes and test drive the vehicle to see if the issue reoccurs.
• If the code persists, further diagnostics may be needed to test the transmission control module and associated components.