What it means
The power supply circuit B for the generator inverter reports a circuit high condition. Inverter operation may be impaired.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The generator inverter depends on supply circuit B to power its electronics. The control module sets P2CC7 when the monitored voltage is higher than expected, which may indicate an unwanted connection to battery positive or an overvoltage condition.
Common causes
Most likely first.
- Supply wire shorted to B+
- Voltage regulator overvoltage
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Battery or charging system warning light
- Dim or flickering lights
- Difficulty starting or a discharged battery
How to diagnose it
- Review freeze-frame data and charging-system codes to determine when circuit B voltage rose and whether other system voltages were also high.
- Inspect circuit B wiring and connectors for damaged insulation, incorrect routing, corrosion, or a connection to battery positive.
- Check connector pins and supply connections for corrosion or poor contact that could distort the voltage reading.
- Measure circuit B voltage at the inverter connector and compare it with the manufacturer's specification, including during the conditions captured in freeze-frame data.
- If circuit B remains high, isolate the harness and check for a short to B+; test the regulator and inverter supply according to vehicle-specific service information.
Common fixes
- Clean and secure corroded or loose circuit B connector pins.
- Repair circuit B wiring shorted to battery positive.
- Repair or replace a faulty voltage regulator if testing confirms overvoltage.
- Repair or replace the inverter or supply component only if circuit tests identify it as the source.
Can I keep driving?
Limit driving if the charging warning is on or lights are flickering, since an overvoltage fault can damage electrical components and impair charging. Have the system checked promptly, especially if the vehicle enters reduced-power mode.
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.