P05C9
Economy Mode Switch Circuit Low
Generic OBD-II
Common symptoms
What you'll notice
- Check the wiring and connections for any damage or loose connections
- Inspect the economy mode switch for any signs of malfunction or sticking
- Replace the economy mode switch if necessary
- Reset the vehicle's computer system to clear any error codes related to the economy mode switch circuit low error.
Common causes
Most likely first
- Malfunctioning economy mode switch
- Damaged or loose wiring in the economy mode switch circuit
- Faulty economy mode switch circuit sensor
- Low battery voltage
- ECU (Engine Control Unit) failure
How to diagnose & fix
Work through it in order
- Engine runs rough or stalls when idling
- Decreased fuel efficiency
- Difficulty starting the vehicle
- Malfunctioning or flickering dashboard lights
- Limited power and acceleration
Read & clear P05C9 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.