What it means
The negative contactor C of the battery charging system reports a control circuit/open condition. HV charging path 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
Negative contactor C is a high-voltage switch, and its coil control circuit lets the module command it to open or close. This code sets when the module detects an open or interrupted control path, so it may be unable to operate the negative charging contactor.
Common causes
Most likely first.
- Open in coil control wire
- Open contactor coil
- Pin pushed back out of connector body
Symptoms
- Hybrid or EV system warning
- Charging may be disabled
- Vehicle may not start or enter Ready mode
How to diagnose it
- Read freeze-frame data and related codes to identify when negative contactor C lost control-circuit continuity and whether the fault is current or intermittent.
- Check scan-tool data for the module's command to negative contactor C and any available coil or contactor feedback.
- With the high-voltage system made safe under the manufacturer's procedure, have a qualified technician inspect the negative contactor C connector for a backed-out pin, poor seating, corrosion, or damaged wiring.
- Have a technician check continuity through the low-voltage control wires to negative contactor C, isolating the circuit as specified by the manufacturer.
- If the wiring and connector pass, have the technician test the contactor coil and module output circuit to locate the open.
Common fixes
- Seat or repair a pushed-back or loose pin at the negative contactor C connector.
- Repair an open or damaged negative contactor C control wire.
- Replace negative contactor C if its coil is open.
- Repair the module output circuit if testing identifies an open there.
Can I keep driving?
Charging may be disabled, and the vehicle may not enter Ready mode. Avoid relying on it for a trip until its ability to start and charge is confirmed; have high-voltage system work handled by a qualified technician.
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.