P0615

What it means

P0615 is the generic SAE J2012 code for a fault in the starter relay A circuit. The engine control unit or powertrain control module commands the starter relay and monitors its control circuit, and it has seen a voltage or state that does not match what it requested, such as an open circuit, a short or a relay that does not respond. Which relay is 'A' and how the circuit is monitored depends on the vehicle, so wiring diagrams for the specific model are needed.

Symptoms

• Engine cranks slowly, intermittently or not at all
• Starter does not engage when the key or start button is operated, or a single click is heard
• Starter keeps running after the engine has started
• Engine starts only on some attempts
• Malfunction indicator lamp on, sometimes with a start-system warning message
• Push-button start car shows a 'start system fault' style message

Possible causes

• Faulty starter relay (worn contacts or failed coil)likely
• Corroded, loose or damaged connectors or terminals in the relay socket or relay circuitlikely
• Open circuit or short to earth or voltage in the relay control wiringpossible
• Weak battery or poor battery and earth connections causing low voltage during crankingpossible
• Fault in the ignition switch, start button, clutch or brake pedal switch, or gear selector/neutral switch feeding the start request (model dependent)possible
• Fault in the immobiliser, body control module or fuse box that handles the relay (model dependent)rare
• Internal fault in the engine control unit relay driverrare

How to diagnose

1. Read the stored codes and freeze frame data, noting battery voltage and whether other start, immobiliser or communication codes are present
2. Check the battery state of charge and voltage under cranking load, and inspect battery terminals and main earth straps
3. Check the relevant fuses and inspect the starter relay, its socket and connectors for corrosion, heat damage or bent terminals
4. Swap the starter relay with a known good identical relay (where one is shared and fitted in the same fuse box) and see if the symptom or code follows it
5. Using the wiring diagram, test the relay coil supply, the control signal and the earth for continuity, shorts and voltage drop
6. Test the start request inputs such as the clutch switch, brake switch and neutral or park switch with live data, where the model uses them
7. With a scan tool that supports it, command the relay or watch the start request status while operating the key or button
8. Check the starter solenoid feed and starter motor current draw if the relay circuit tests good

How to fix

• Replace the starter relay with the correct specification part
• Clean or repair the relay socket, terminals and connectors, and fit new terminals where they are damaged
• Repair or replace damaged wiring in the relay control circuit
• Recharge or replace a weak battery and repair poor power and earth connections
• Replace the faulty start-request switch or input component that was identified
• Repair or replace the control unit or fuse box only after the wiring, relay and inputs have been proven good

Can I keep driving?

Nearby codes

• P0614GenericECM/TCM Incompatible
• P0616GenericStarter Relay A Circuit Low