What it means
The control circuit of the HV battery positive contactor reports a control circuit high condition. HV main switching cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The positive contactor is the high-voltage switch on the battery pack's positive side, and its control circuit tells the module whether it can operate that switch. P0ADC sets when the circuit signal is higher than expected, which can be caused by a short to battery positive, an open contactor coil, or a poor connection.
Common causes
Most likely first.
- Control wire shorted to B+
- Open contactor coil
- Connector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Review freeze-frame data and related contactor codes to learn when the high-circuit reading was detected.
- Follow high-voltage safety procedures, then inspect accessible positive contactor control wiring and connector terminals for damage or corrosion.
- Using the manufacturer's isolation procedure, test the control wire for a short to battery positive.
- Test the positive contactor coil for an open circuit and check connector contact quality using the manufacturer's procedure.
- Compare circuit readings with the manufacturer's specification and trace the source of the high signal before replacing parts.
Common fixes
- Repair wiring shorted to battery positive in the positive contactor control circuit.
- Repair a loose or corroded connector terminal.
- Replace the positive contactor if its coil is open.
- Repair harness damage that lets the control wire contact a power feed.
Can I keep driving?
Do not continue driving if the vehicle cannot enter READY mode, loses propulsion, or displays a high-voltage warning; the positive contactor may not connect the pack correctly. Keep clear of high-voltage components and arrange qualified hybrid service.
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.