What it means
Starter relay D reports a stuck on condition. Engine cranking can be inhibited or commanded unintentionally.
At a glance
- Usually lights the check-engine light
How it works
Starter relay D switches power to the starter circuit when the control module requests cranking. The module checks whether relay D stops supplying power when it should be off; it sets this code if the relay output remains on, potentially keeping the starter engaged after the engine starts.
Common causes
Most likely first.
- Relay contacts welded closed
- Output driver stuck on
- Carbon or debris buildup preventing free movement
Symptoms
- Check-engine light may be on
- Starter may continue running after the engine starts
- Unusual starter noise
How to diagnose it
- Save the code and freeze-frame data, then check whether the starter continues turning after the engine starts or with the ignition request off.
- Use the vehicle wiring diagram to locate relay D and inspect its socket, terminals, and wiring for heat damage, contamination, or corrosion.
- With the circuit made safe, check whether relay D's switched contacts remain closed when the relay is de-energised.
- Compare the module's command for relay D with the relay output to determine whether the relay is stuck or the control side is still requesting it.
- If the output stays on with a known-good relay and no command, test the relay D control wiring and module output driver using the manufacturer's procedure.
Common fixes
- Clean debris from the relay D socket and ensure the relay moves freely.
- Repair damaged, contaminated, or loose relay D socket terminals and wiring.
- Replace relay D if its contacts remain closed when de-energised.
- Repair the relay D output driver circuit if it supplies power without a command.
Can I keep driving?
If the starter keeps running after the engine starts, stop the engine as soon as it is safe and avoid further starts; an engaged starter can overheat and be damaged. If the starter is not staying engaged, limit driving and arrange prompt repair because the relay may activate unexpectedly.
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.