What it means
The supply voltage on injector group C is above the upper limit. Overvoltage on the group-C supply can mis-time or damage the injectors. Causes: charging-system overvoltage, a stuck supply relay or regulator, or a wiring fault shorting the group-C supply to a higher voltage.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Injector group C receives power through a shared supply circuit, and the engine control module switches each injector to deliver fuel. This code sets when the module detects group C supply voltage above its expected upper limit, which can interfere with injector operation or damage components.
Common causes
Most likely first.
- Charging system overvoltage
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
How to diagnose it
- Record freeze-frame data and check live misfire counts to see when the group C voltage fault occurs and which cylinders are affected.
- Inspect the group C supply wiring and connectors for a pinched wire against a higher-voltage source, damaged insulation, or corrosion.
- Measure charging-system voltage under the conditions recorded in freeze-frame data and compare it with the manufacturer's specification.
- Measure group C supply voltage and compare it with the manufacturer's specification to confirm the high reading.
- If charging voltage is normal, test the group C supply relay and trace the circuit for a short to a higher-voltage source.
Common fixes
- Repair a group C supply wire shorted to a higher-voltage source.
- Clean or replace damaged group C connector terminals.
- Replace a relay that is stuck or supplying voltage improperly.
- Repair the charging system if its output exceeds the manufacturer's specification.
Can I keep driving?
Limit driving if the engine misfires or runs roughly, since continued misfiring can damage the catalytic converter; excessive charging voltage may also affect other electrical components. Stop if smoke or a strong fuel smell appears.
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.