What it means
The negative contactor D of the battery charging system reports a stuck closed 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 D is a high-voltage switch that should open and close only when commanded. This code sets when the control module detects that the D contactor remains electrically closed when it should be open, so the charging path cannot be controlled reliably.
Common causes
Most likely first.
- Contactor contacts welded closed
- Output driver stuck on
- Carbon or debris buildup preventing free movement
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 confirm when the module detected contactor D closed and whether other contactors show the same condition.
- Check scan-tool data for the command and reported state of negative contactor D, especially after the module commands it open.
- With the vehicle safely powered down under the manufacturer's procedure, inspect the contactor D connector and accessible wiring for shorts or damage that could keep it energised.
- Have a qualified technician isolate the high-voltage system and test whether contactor D's contacts remain closed when the coil is not commanded.
- If the contacts are not welded, test the control-module output for a stuck-on signal using the manufacturer's procedure.
Common fixes
- Repair wiring or connector damage that keeps the contactor D coil energised.
- Replace negative contactor D if its contacts are welded or it cannot release.
- Repair the control-module output if testing confirms it is continuously commanding the contactor on.
- Clear the code and verify that contactor D opens when commanded.
Can I keep driving?
Do not continue driving if the vehicle will not enter Ready mode or displays a high-voltage warning; arrange safe recovery. A contactor that stays closed can prevent reliable isolation of the charging path.
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.