Fuel Injector Control Module Relay Circuit Malfunction
The P0612 code indicates a fault in the fuel injector control module relay control circuit. This relay supplies power to the fuel injector control module, which manages injector timing and fuel delivery. When the powertrain control module (PCM) detects an open, short, or excessive resistance in the relay control circuit, it sets this code. Common causes include a faulty relay, wiring issues, or a defective fuel injector control module.
01. Most Common Causes
- Faulty fuel injector control module relay
- Open or shorted wiring in the relay control circuit
- Corroded or loose relay connections
- Defective fuel injector control module
- Failed PCM (rare)
02. Symptoms You Will Notice
- Engine misfire or rough idle
- Hard starting or no start condition
- Reduced engine power and poor acceleration
- Check Engine Light illuminated
- Possible stalling while driving
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Inspect the fuel injector control module relay and its wiring for damage, corrosion, or loose connections.
Step 3: Test relay operation using a multimeter (check coil resistance and continuity).
Step 4: Check for power and ground at the relay socket with the ignition on.
Step 5: If relay and wiring are okay, test the fuel injector control module per manufacturer procedure.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The vehicle may stall or fail to start, leading to a potential accident. Have it diagnosed and repaired immediately.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on whether the relay or module needs replacement.