Fuel Injection Quantity Too High
The ECU has detected that the actual fuel injection quantity is higher than expected.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine's computer thinks it's giving too much fuel to the engine compared to what it should, which can lead to poor performance and increased emissions.
What the computer is actually seeing
The engine control unit (ECU) monitors fuel rail pressure, injector pulse width, and the actual fuel that flows into the combustion chamber. It expects certain values based on load and RPM. If the amount exceeds its programmed limits, it triggers this code.
What a healthy reading looks like
Fuel injection duration (pulse width) should be between 1.0 ms and 8.0 ms depending on engine load; fuel rail pressure should be within 40-60 psi at idle for most diesel engines.
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.
- 11. Check wiring and connectors for corrosion or breaks related to fuel injectors and fuel rail.
- 22. Confirm fuel levels in the tank are adequate; ensure there are no leaks visible in fuel lines.
- 33. Test the fuel pressure at the rail to ensure it’s within expected values (40-60 psi); replace the fuel filter if clogged.
- 44. Use a scan tool to check for any related codes like SPN 163 for fuel pressure; resolve any additional codes.
- 55. Inspect for injector spray pattern using a scope tool; replace any injectors showing signs of leaking or improper pattern.
Common causes
- Faulty fuel injectors
- Leaking fuel lines or injector seals
- ECU calibration error
- Faulty fuel pressure regulator
- High fuel temperature
- Contaminated fuel
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; drivability can be affected, and excessive fuel can lead to engine damage over time.
Will the code come back after clearing it?
If the underlying issue isn't fixed, yes, the code will likely return.
Why does this code show up with high fuel pressure?
High fuel pressure can lead to excessive injection rates, causing this code to trigger.
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