What it means
The negative contactor D of the battery charging system reports a circuit 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 switch in the high-voltage battery charging path. The control module checks whether its electrical circuit responds as expected when the contactor is commanded; this code sets when the circuit reports a fault without specifying a low, high, stuck-open, or stuck-closed condition.
Common causes
Most likely first.
- Contactor failed
- Wiring or connector fault
Symptoms
- Hybrid or EV system warning
- Charging may fail or stop
- Vehicle may not enter Ready mode
How to diagnose it
- Read freeze-frame data and related hybrid or EV codes to see when contactor D failed and whether other charging-path faults are present.
- Use a scan tool to compare the command for negative contactor D with its reported status during the conditions that set the code.
- With the vehicle safely powered down according to the manufacturer's procedure, inspect the contactor D connector and accessible wiring for damage, looseness, corrosion, or moisture.
- Have a qualified technician test the contactor D control circuit and coil against the manufacturer's specification, following the required high-voltage isolation procedure.
- If the wiring and coil pass, check the contactor's switching response and control-module output using the manufacturer's diagnostic procedure.
Common fixes
- Repair a loose, damaged, or corroded contactor D connector or wire.
- Restore the contactor D circuit connection and clear the fault after confirming the repair.
- Replace negative contactor D if its coil or switching action fails the manufacturer's tests.
- Repair the control-module output only if circuit testing identifies it as the cause.
Can I keep driving?
Avoid relying on the vehicle for trips if charging is unreliable or it will not enter Ready mode. Stop using it if a high-voltage warning appears or the vehicle behaves unpredictably; continued operation may leave it unable to start or charge.
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.