P0612
UniversalThe Fuel Injector Control Module (FICM) Relay Control Circuit monitors the voltage signal sent to the FICM relay. This code is set when the Powertrain Control Module (PCM) detects an incorrect voltage reading or an open/short in the circuit.
High SeverityThis code indicates a problem with the electrical circuit controlling the relay for the Fuel Injector Control Module (FICM). This mechanical failure can lead to the engine not receiving proper fuel, resulting in poor performance or a no-start condition.
⚠️ Before You Begin (Safety First)
Always disconnect the negative battery terminal before working on electrical components. Be cautious when handling fuel system components as fuel can be flammable and under high pressure.
Common Symptoms
- Check Engine Light illuminated
- Engine cranking but not starting
- Engine misfires
- Rough idling
- Reduced engine power
- Stalling
Common Causes
- Faulty FICM relay
- Open or short in the FICM relay control circuit wiring
- Corroded or loose electrical connectors
- Faulty Fuel Injector Control Module (FICM)
- Faulty Powertrain Control Module (PCM) (less common)
Frequently reported on: Ford F-250/F-350 (2003-2007 6.0L Powerstroke), Chevrolet Silverado/GMC Sierra (2001-2010 Duramax), Dodge Ram (2003-2007 5.9L Cummins)
Diagnostic Steps
- Visually inspect the FICM relay and its electrical connector for signs of damage or corrosion.
- Check the fuses related to the FICM and the fuel system. Replace any blown fuses.
- Test the FICM relay using a multimeter to ensure it's functioning correctly. You can swap it with a known good relay of the same type if available.
- Use a multimeter to check for continuity and proper voltage in the FICM relay control circuit wiring.
- If possible, test the FICM's power supply and ground circuits.
👨🔧 When to Call a Professional
If basic diagnostics like checking fuses and the relay do not resolve the issue, or if you suspect a faulty Fuel Injector Control Module itself, it's best to consult a professional mechanic. The FICM is an expensive component and requires careful diagnosis.
Commonly Asked Questions
What is the Fuel Injector Control Module (FICM)?
The FICM is an electronic module, primarily found in some diesel engines, that provides the necessary high voltage to the fuel injectors for precise fuel delivery.
Can I drive with a P0612 code?
It is not recommended to drive with this code as it can lead to severe engine performance issues, including stalling or a no-start condition, which can be dangerous.
Is a P0612 code always a faulty FICM?
No, the code specifically points to an issue with the FICM relay control circuit. It could be the relay itself, wiring, or connectors, before concluding the FICM is faulty.
How expensive is it to fix a P0612 code?
The cost can vary significantly. A simple relay replacement might be inexpensive (under $50), while diagnosing and repairing wiring could range from $100-$300+. A new FICM, if needed, can cost $500-$1500+ for the part alone, plus labor.