P0615: Starter relay: circuit fault
The ECU detects a problem in the circuit that switches the starter motor relay. Usually the relay itself, a fuse or the wiring.
| Code | P0615 |
|---|---|
| System | Engine and transmission |
| Group | P06xx, Control unit and auxiliary outputs |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0615 means
When you turn the key or press the start button, the ECU switches a relay that powers the starter motor. This code means that relay circuit is not behaving as expected. It can stop the car starting, or make it start only some of the time.
Most common causes
- Faulty or poorly seated starter relay
- Blown fuse in the starting circuit
- Relay plug or wire loose, broken or corroded
- Low battery not giving enough voltage
- Clutch, park/neutral or brake switch not giving its signal
Symptoms
- Engine warning light on
- Car does not crank or does nothing when you try to start
- Starting only works some of the time
Can you drive with P0615?
With care Once running it drives normally, but it may not start again next time. Get it checked soon so you are not stranded.
How to check it
When you try to start, listen for the relay clicking in the fuse box. Check the starter fuse and, if the car uses an identical relay for another job, swapping them is a quick test.
How to read and clear P0615 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0615 with this same explanation and whether it’s confirmed, pending or permanent.
With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.
Similar codes
- P0604 Internal control module random access memory (RAM) error
- P0605 Internal control module read only memory (ROM) error
- P0606 ECM/PCM processor fault
- P0607 Control module performance
- P0616 Starter relay: circuit low
- P0617 Starter relay: circuit high
- P0620 Generator control: circuit fault
- P0621 Generator lamp L control: circuit fault
- P0600 Serial communication link fault
- P0601 Internal control module memory checksum error
- P0602 Control module programming error
- P0603 Internal control module keep alive memory (KAM) error
P0615 is a generic code, so it means the same on any make, for example on BMW, Ford, Mazda, Mercedes-Benz, Peugeot, Volkswagen. See what Final OBD does on your car in makes and models.
What does code P0615 mean?
When you turn the key or press the start button, the ECU switches a relay that powers the starter motor. This code means that relay circuit is not behaving as expected. It can stop the car starting, or make it start only some of the time.
Can you drive with P0615?
Once running it drives normally, but it may not start again next time. Get it checked soon so you are not stranded.
How do you clear P0615?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0615 comes back.
Read it on your car
Final OBD reads the faults of every control unit for free, including each make’s own codes, and with Pro explains each one in plain English. Free clears engine faults at no cost.
Coming soon
Mid to late October 2026
If you want to try it in your car before anyone else, send us your email and we will add you as a tester.
info@finalobd.com