VGT Actuator Circuit - Voltage High
The CAT-CID2452-FMI3 (Caterpillar) diesel fault code means: VGT Actuator Circuit - Voltage High. This is a moderate severity code.
Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.
- Keep driving?
- Short distances only
- DIY difficulty
- advanced
- Estimated cost
- $800-$4500
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View pilot availability →What Are the Symptoms of CAT-CID2452-FMI3?
- Low boost / low power / derate
- Black smoke under load
- Turbo whistle changes or absent
- Check Engine Light
- Poor fuel economy
What Causes CAT-CID2452-FMI3? (Most Likely First)
- Carbon buildup on VGT vanes from soot Possible
- VGT actuator electronic or mechanical failure Likely
- Wiring or connector issue at turbo actuator Likely
- Calibration lost after battery disconnect or ECM work Less Likely
- EGR system flooding turbo with soot (failed EGR cooler) Possible
Can I Still Drive with CAT-CID2452-FMI3?
Short distances only. CAT-CID2452-FMI3 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What is CAT code CID2452-FMI3?
CAT code CID2452-FMI3 (VGT Actuator Circuit - Voltage High) is a moderate-severity fault on C13 and C15 ACERT engines. VGT actuator signal voltage too high, typically open wire. The C15 ACERT uses a variable-geometry turbo that is carbon-prone on high-idle applications.
Why does this happen on CAT ACERT engines?
ACERT engines use heavy EGR plus VGT, and the combination dumps soot on the vanes. Trucks that idle a lot or run light loads are especially prone. Regular loaded operation and EGR cooler integrity help prevent VGT issues.
How much does it cost to fix CAT CID2452-FMI3?
Cleaning carbon from VGT vanes is a $800-$1500 labor job at a shop. A new VGT actuator runs $1500-$2500. Full turbo replacement with cartridge is $3500-$4500.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose CAT-CID2452-FMI3?
Connect CAT ET, command VGT actuator through its full range with the engine off; watch position feedback.
If actuator does not follow command, remove and inspect vanes for carbon / seized movement.
On C15 ACERT, soak vanes in carbon cleaner or replace actuator if electronic fault is confirmed.
Perform VGT actuator re-learn / calibration in CAT ET after service.
Check EGR cooler function — EGR cooler failure dumps soot into the intake and accelerates VGT issues.
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)
Which Vehicles Commonly Get CAT-CID2452-FMI3?
- 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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