What it means
General electrical fault on the starter relay control circuit driven by the ECU/PCM. Typical symptom is a no-crank or intermittent crank condition.
At a glance
- Usually lights the check-engine light
How it works
The starter relay circuit lets the powertrain control module command the starter relay when starting conditions are met. P0615 sets when the module detects an electrical fault in that relay-control circuit, which can result from a failed relay, wiring or connector trouble, or a fault in the control output.
Common causes
Most likely first.
- Starter relay failed
- Wiring or connector fault
Symptoms
- No-crank or intermittent starting
How to diagnose it
- Save freeze-frame data and scan for starting-system and voltage faults, then note whether the fault coincides with a no-crank or intermittent crank.
- Inspect the starter relay and socket, battery connections, and related wiring for corrosion, looseness, heat damage, or broken insulation.
- Check the relay and its supply and control connections using the manufacturer's wiring diagram and test procedure.
- With a helper and the vehicle safely secured, check whether the relay receives a start command and whether its output reaches the starter circuit; avoid working near moving parts.
- If the relay and wiring pass, test the control wire and module output according to the manufacturer's procedure before considering module repair.
Common fixes
- Clean and secure battery, relay, and connector contacts.
- Repair damaged or high-resistance starter-relay control wiring.
- Replace the starter relay if it fails the manufacturer's test.
- Repair the control-module output only if the relay and circuit test correctly and the fault is confirmed there.
Can I keep driving?
A no-crank or intermittent start can leave you stranded, so avoid relying on the vehicle for trips where restarting is important. If it starts and runs normally, driving does not usually worsen this circuit fault, but the next restart may fail.
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.