P2777 Fault Code

Upshift Switch Circuit High

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

The P2777 fault code indicates an issue with the upshift switch circuit being detected as having a high signal. This switch is crucial for transmission operation as it signals when to shift gears for optimal performance. A malfunctioning circuit can lead to improper shifting, resulting in decreased vehicle performance and efficiency.

What are the symptoms of the P2777 code?

• Erratic shifting behavior of the transmission
• Difficulty in upshifting to higher gears
• Transmission may go into limp mode
• Illuminated check engine light
• Poor fuel economy due to inefficient shifting

What causes the P2777 code?

• Faulty upshift switch
• Damaged wiring harness or connectors
• Short circuit in the upshift switch circuit
• Issues with the Transmission Control Module (TCM)
• Corrosion in the electrical connections

How to fix P2777?

• Inspect the upshift switch for damage or malfunction
• Check the wiring harness and connectors for signs of wear or corrosion
• Repair or replace any damaged wires or connectors
• Test the operation of the Transmission Control Module
• Clear the fault code and conduct a road test to ensure proper operation