What it means
Starter relay D reports a stuck off condition. Engine cranking can be inhibited or commanded unintentionally.
At a glance
- Usually lights the check-engine light
How it works
Starter relay D supplies the starter circuit when the control module requests cranking. The module checks whether relay D delivers its commanded output; it sets this code when the relay remains off or fails to pass current, which can prevent cranking or make starting intermittent.
Common causes
Most likely first.
- Relay contacts oxidised - high resistance
- Relay coil burned out
- Carbon or debris buildup preventing free movement
Symptoms
- Check-engine light may be on
- Engine may not crank
- Intermittent starting difficulty
How to diagnose it
- Save freeze-frame data and note whether the engine fails to crank, cranks intermittently, or starts normally when the code is present.
- Use the vehicle wiring diagram to identify relay D, then inspect its socket, terminals, and wiring for corrosion, looseness, or debris.
- Check the relay D coil and switched-contact continuity against the manufacturer's specification.
- When a start request is made, compare the module command, relay coil activation, and relay output to find where power stops.
- If relay D does not receive the expected command, test its control wiring and module driver according to the manufacturer's procedure.
Common fixes
- Clean debris from the relay D socket and restore secure terminal contact.
- Repair corroded or loose relay D connector terminals and wiring.
- Replace relay D if its coil is open or its contacts fail to conduct as specified.
- Repair the relay D control circuit if the module command does not reach the relay.
Can I keep driving?
If the vehicle starts reliably and the starter disengages normally, a short drive may be possible, but avoid trips where a no-start would leave you stranded. If cranking is intermittent or absent, do not rely on the vehicle until the fault is repaired.
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.