Fuel Mode Indicator Lamp Control Circuit
What it means
P2668 means the engine computer found a fault in the circuit that drives the fuel-mode indicator lamp — the light that tells the driver which fuel is in use on flex-fuel or bi-fuel vehicles. It affects only the indicator, not how the engine runs, so it's a low-priority electrical fault: usually a bulb, wiring, or connector problem.
Can I keep driving? Safe to drive — this affects only the fuel-mode indicator lamp; the engine runs normally.
Real-world scan data
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on
- Fuel-mode indicator lamp stays off, stuck on, or reads wrong
- No change in how the engine starts or runs
Common causes
Most likely first
- Burned-out fuel-mode indicator bulb or LEDLikely
- Open or shorted wiring in the lamp control circuitCommon
- Corroded or loose instrument-cluster or lamp connectorCommon
- Faulty PCM lamp-driver outputLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame to confirm the lamp control circuit fault.
- Check the indicator bulb/LED and its power and ground.
- Inspect the lamp control wiring and connector for opens or shorts.
- Test the PCM driver output if the wiring is good.
- Repair the circuit and clear the code.
FAQ
Quick answers
Is it safe to drive with P2668?+
Can I just clear P2668?+
Related codes
Read & clear P2668 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.