What it means
The negative contactor D of the battery charging system reports a control circuit high 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
The control circuit for negative contactor D operates the switch in the high-voltage charging path. This code sets when the module detects a control-circuit signal higher than expected, which can occur with a short to battery voltage, an open coil, or resistance at a connector.
Common causes
Most likely first.
- Control wire shorted to B+
- Open contactor coil
- Connector pins corroded - high contact resistance
Symptoms
- Hybrid or EV system warning
- Charging may be disabled
- Vehicle may not start or enter Ready mode
How to diagnose it
- Review freeze-frame data and related codes to establish when the high signal appeared and whether other contactor circuits are affected.
- Use scan-tool data to compare the D contactor command with its circuit status during the fault.
- With the vehicle safely powered down per the manufacturer's procedure, inspect the D control wiring and connector for damage, corrosion, or contact with a power feed.
- Have a qualified technician test the control wire for a short to battery voltage and check the contactor D coil against the manufacturer's specification.
- If wiring and coil tests pass, check the module's D control output using the manufacturer's diagnostic procedure.
Common fixes
- Repair a control wire shorted to a power feed.
- Repair or replace a damaged, corroded, or loose contactor D connector.
- Replace negative contactor D if its coil is open or outside the manufacturer's specification.
- Repair the control-module output if testing confirms it is driving the circuit high.
Can I keep driving?
Avoid relying on the vehicle for charging or startup while the warning persists. If it cannot enter Ready mode or shows a high-voltage warning, stop using it and arrange safe recovery.
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.