Fuel Injection Control Modulation
Fault in fuel injection control modulation system.
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What it means (plain English)
The fuel injection system is not regulating fuel flow correctly, which can affect engine performance and fuel efficiency.
What the computer is actually seeing
The ECM monitors fuel injection pressure and duration. If the values deviate from expected ranges due to a fault in the control module, it triggers this code.
What a healthy reading looks like
Fuel pressure should be within 4-6 bar (58-87 psi) when the engine is running; injection duration should be within specified parameters based on engine RPM.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Inspect the wiring and connectors for the fuel injection control module for corrosion or damage. Decision Point: If wiring is damaged, repair it and retest; if wiring is fine, proceed to step 2.
- 2Check the fuel levels and ensure adequate fuel supply to the engine. Decision Point: If fuel level is low, refill and retest; if fuel level is good, proceed to step 3.
- 3Measure fuel pressure at the rail. Expected pressure is 4-6 bar (58-87 psi). Decision Point: If pressure is out of specs, test the fuel pump and pressure regulator; if pressure is normal, proceed to step 4.
- 4Scan for any other active fault codes that may relate to fuel system performance. Decision Point: If there are other codes, address those; if none, proceed to step 5.
- 5Test the fuel injectors and FICM for proper operation using a multimeter. Decision Point: If either component fails, replace it; if both are operational, further diagnostics on the EFI system may be needed.
Common causes
- Faulty fuel injection control module (FICM)
- Wiring or connector damage to the FICM
- Fuel pressure regulator malfunction
- Contaminated fuel
- Faulty injectors
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with SPN 1506?
It's moderate severity; you may experience reduced performance but generally it's safe for short distances.
Will this code come back after clearing?
Yes, if the underlying issue is not fixed, the code will likely return.
Why does this code pair with SPN 2002?
SPN 2002 relates to fuel pressure; issues often affect both fuel injection and pressure regulation.
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