OBD-II code · Powertrain (generic, extended)
P28C1 Ion Sense Module Supply Voltage Low
Supply voltage on the ion sense module is below the expected window. Wiring shorted to ground, blown fuse, or upstream regulator fault.
Is it safe to drive with P28C1?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyModule supply fuse blown
- PossibleSupply wire shorted to ground
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- Parts involved
- Ion Sense Module, Wiring Harness
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.