OBD-II Diagnostic Trouble Code
P0617 — Starter Relay Circuit High
P0617 means the ECM saw the starter relay control circuit voltage higher than expected. That indicates the circuit is shorted to battery voltage or is open, depending on how the manufacturer monitors it. In some designs, a short to power can keep the starter relay energized.
Severity 3/5
Truck-relevant
Service this week
Severity
Service this week
Starter Relay Circuit High
Code
P0617
Category
Powertrain
Subsystem
Ignition
Truck-relevant
Yes
What this means for truckers
P0617 (Starter Relay High) — open circuit.
Before you replace parts — try this first
P0617 on the Ignition system is most often starter relay with an open coil or a relay not seated in its socket — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
The starter may stay engaged after the engine starts (grinding, overheated starter), or there may be a no-crank if the circuit is open. The check-engine light may come on. Treat a starter that stays engaged as urgent.
Common causes
- CommonStarter relay with an open coil or a relay not seated in its socket ($40–$200)
- OccasionalControl wire shorted to a battery or ignition feed ($120–$450)
- OccasionalOpen circuit or loose terminal in the relay control circuit ($60–$300)
- RareFailed ECM driver ($1200–$3500)
How to fix
Replace the starter relay and check whether the starter disengages properly, since a relay with welded contacts can also keep the starter running
When to use: First, especially if the starter stays engaged
With the relay removed, check the control circuit for voltage with the key off and in run
When to use: To find a short to power
Check the circuit for opens and poor terminal fit
When to use: When there's a no-crank with this code
Inspect the starter and flywheel ring gear for damage
When to use: When the starter stayed engaged while the engine was running
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0670 — Glow Plug Control Module Circuit
- → P0671 — Cylinder 1 Glow Plug Circuit
- → P0672 — Cylinder 2 Glow Plug Circuit
- → P0673 — Cylinder 3 Glow Plug Circuit
- → P0674 — Cylinder 4 Glow Plug Circuit
Frequently Asked Questions
Can I drive with code P0617?
P0617 is severity 3 — plan service within a few days. Performance is likely degraded already (you may feel reduced power, harsher shifts, or slightly worse fuel economy). Continuing to drive risks additional damage to adjacent components.
How much does it cost to fix P0617 on a commercial truck?
Total repair cost ranges $40–$3500 depending on the root cause. The cheapest fix is usually the first one listed below — Starter relay with an open coil or a relay not seated in its socket — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P0617 fail a DOT inspection?
P0617 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between P0617 and related codes?
P0617 is closely related to: P0670 (Glow Plug Control Module Circuit), P0671 (Cylinder 1 Glow Plug Circuit), P0672 (Cylinder 2 Glow Plug Circuit), P0673 (Cylinder 3 Glow Plug Circuit). These codes share the same subsystem (ignition) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P0617 is set without the companions, the issue is more isolated.
How do I prevent P0617 from coming back after a repair?
For P0617 (Starter Relay Circuit High), prevention centers on the ignition system. Use OEM-spec injectors and spark plugs (gas). Address fuel quality issues immediately — bad fuel kills injectors. Cylinder balance test annually for early warning.