OBD-II code · Powertrain (generic, extended)
P28C2 Ion Sense Module Supply Voltage High
Supply voltage on the ion sense module is above the expected window. Charging system overvoltage or upstream regulator fault.
Is it safe to drive with P28C2?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyAlternator regulator drift - overvoltage
- PossibleSupply wire shorted to B+
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.