P05C7

Symptoms

• Check Engine Light Is On
• Eco mode is not activated when pressing the button
• Eco Mode button does not respond to presses
• There is no indication of active Eco mode on the instrument panel
• Possible slight increase in fuel consumption

Causes

• Broken wire in the Eco Mode switch circuit
• Poor contact or oxidation in switch connector
• Faulty switch (broken internal contacts)
• Damage to wiring during repairs or exposure to external factors
• Malfunction in the control unit (rare)

How to Fix

1. Connect the diagnostic scanner, read all error codes and frozen frame data
2. Find the Eco Mode switch according to the car's electrical diagram
3. Inspect the switch connector - check contacts, moisture, oxidation
4. Use a multimeter to check the integrity of the wiring from the switch to the ECU
5. Check the switch itself for functionality (resistance/short circuit when pressed)
6. Replace the switch or repair damaged wiring

Related codes

Error P05C7 by Vehicle Brand