What it means
Voltage on the fuel mode indicator lamp control line is above the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
The control module operates the fuel mode indicator lamp through a dedicated control line and checks the line voltage. This code sets when that voltage is above its expected range, which can keep the indicator off or make it stay illuminated.
Common causes
Most likely first.
- Control wire shorted to B+
- Burnt-out indicator bulb
- Connector pins corroded - high contact resistance
Symptoms
- Fuel mode warning or check-engine light may be on
- Fuel mode indicator may not illuminate or may stay on
How to diagnose it
- Use a scan tool to review freeze-frame data and check fuel mode status and lamp command data, if available.
- Check whether the fuel mode indicator is off, continuously lit, or behaving differently as the selected mode changes.
- Inspect the indicator bulb or assembly and its connector, then trace the control wire for a short to battery voltage or damaged insulation.
- Check the circuit terminals for corrosion, looseness, or poor contact that could interfere with the lamp control signal.
- Test the control wire and module output against the manufacturer's circuit procedure to distinguish a wiring fault from a failed driver.
Common fixes
- Repair a control wire shorted to battery voltage.
- Clean or repair corroded, loose, or damaged indicator circuit terminals.
- Replace a failed fuel mode indicator bulb or assembly.
- Repair or replace the control module if its lamp driver is confirmed faulty.
Can I keep driving?
The vehicle may still run, but the indicator may not reliably show the selected fuel mode. Confirm the mode through the vehicle’s controls and address the fault soon.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.