Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble with the switch that helps the car change gears. It's like if a light switch in your house was flickering on and off by itself.
The P2778 code indicates that the transmission control module (TCM) has detected an intermittent or erratic signal from the upshift switch circuit.
The upshift switch is part of the vehicle's transmission system, allowing the driver to manually shift gears. The TCM monitors the switch's electrical circuit for consistent signals. If the signal is erratic or intermittent, the TCM triggers the P2778 code.
• Erratic shifting
• Transmission stuck in one gear
• Check Engine Light illuminated
• Faulty upshift switch
• Damaged wiring or connectors in the upshift switch circuit
• Malfunctioning transmission control module (TCM)
TCM: Transmission Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Check for other transmission-related codes.
• Inspect the upshift switch and its wiring for damage.
• Test the upshift switch for proper operation.
• Replace the faulty upshift switch.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the TCM if necessary.
• OBD-II scanner
• Multimeter
• Screwdriver set
$150 - $400
Moderate
• Toyota Camry
• Honda Accord
• Ford Fusion
• Regular inspection of transmission components
• Timely servicing of the transmission system
• Avoiding harsh driving conditions
Transmission Control Issue
• Drive cautiously until the issue is resolved.
• Avoid manual shifting if possible.
Check with your vehicle manufacturer for specific warranty coverage on transmission components.
This code has been associated with vehicles that have manual shift mode options and is more common in vehicles with higher mileage.
Moderate – It is advisable to address this issue soon to prevent further transmission damage.
Driving with a malfunctioning transmission can be unsafe. Address the issue promptly to ensure vehicle safety.
• Vehicle must be in a safe location to test gear shifting.
• Engine should be at normal operating temperature.
The upshift switch is typically located on the gear shifter or steering column, depending on the vehicle model.
Q: Can I drive with a P2778 code?
A: It's possible to drive, but it's not recommended as it may cause further transmission issues.
Q: How do I reset the P2778 code?
A: After repairing the issue, you can use an OBD-II scanner to clear the code from the vehicle's computer.
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