P0617 — Starter relay circuit voltage too high

The code indicates a problem with the starter relay circuit receiving higher voltage than expected. It usually appears when the engine control module detects an electrical issue in the starter relay wiring or relay itself. This can cause starting problems or electrical faults but often does not stop the car from running once started.

Common causes

The cause is almost always one of a few things. Here they are — P0617 rarely comes from anything outside this list:

• Faulty or sticking starter relay
• Damaged or corroded wiring/connectors in starter circuit
• Poor ground connection for starter relay
• Faulty engine control module (rare)

Where to start

In the order a sensible mechanic would work — the cheap checks first, the expensive replacements only after:

1. Check and clean battery terminals and ground connections
2. Inspect wiring and connectors for damage or corrosion
3. Test and replace starter relay if faulty
4. Check starter motor and related components if problem persists

That is what holds for P0617 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.