Cylinder 5 Injector - Bad Intelligent Device or Component
The CAT-INJ5-FMI12 (Caterpillar) diesel fault code means: Cylinder 5 Injector - Bad Intelligent Device or Component. This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- advanced
- Estimated cost
- $400-$1800
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Common Symptoms
- Check Engine Light
- Dead cylinder
- Power loss
- CAT ET flags injector trim / solenoid coil failure
Probable Causes (Ranked by Likelihood)
- Internal injector electronic failure Very Likely
- Missing injector trim code in ECM Possible
Frequently Asked Questions
What does CAT code INJ5-FMI12 mean?
CAT code INJ5-FMI12 (Cylinder 5 Injector - Bad Intelligent Device or Component) is a serious-severity fault on Caterpillar on-highway diesel engines. This code flags cylinder 5 injector fault. CAT on-highway engines use HEUI (hydraulically actuated) injection pre-2007 and common rail post-2007. Confirm with CAT ET cylinder cutout test before replacing a $500-$800 injector. Diagnose with CAT ET (Electronic Technician) software.
Can I drive my truck with CAT code INJ5-FMI12?
Short distances may be acceptable, but running long with this fault risks progressive damage or forced derate. Address promptly.
How much does it cost to fix CAT INJ5-FMI12?
Typical repair is $400-$1800. Sensor / wiring fixes fall at the low end; injector, HEUI pump, turbo, or aftertreatment work falls at the high end. CAT dealer labor often requires CAT ET for calibration and parameter programming.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
Verify with CAT ET that the injector trim code matches the physically installed injector.
If trim is correct, perform cylinder cutout and solenoid resistance check.
Replace injector and program trim code.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J1939-73Application Layer: Diagnostics (defines the SPN/FMI fault-identifier framework)
Commonly Affected Vehicles
- Kenworth T800 with CAT C15
- Kenworth W900 with CAT C15
- Kenworth T2000 with CAT C15
- Peterbilt 379 with CAT C15
- Peterbilt 389 with CAT C15
- Peterbilt 386 with CAT C15
- Peterbilt 387 with CAT C15
- Freightliner Classic XL with CAT C15
- International 9200i with CAT C15
- International 9400i with CAT C15
- Western Star 4900 with CAT C15
- Western Star 5900 with CAT C15
- Kenworth T800 with CAT C13
- Kenworth T660 with CAT C13
- Peterbilt 386 with CAT C13
- Peterbilt 387 with CAT C13
- Freightliner Columbia with CAT C13
- International 9200i with CAT C13
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