Caterpillar Fault Code
Free · no signupSPN 102 FMI 18
Power Loss / Black Smoke
Variant 1
System
Air Intake
Symptom
Power Loss / Black Smoke
Diagnosis & fix steps
LOGIC: Intake Manifold Boost Pressure Below Normal Operating Range.
ACTION: Inspect charge air cooler (CAC) boots for splits, check wastegate linkage travel, and verify boost pressure sensor line is free of soot accumulation.
Red Seal field insights
Physics: Air leak downstream of turbo causes incorrect air-fuel ratio, forcing ECM into derate to protect turbo from overspeeding.
Variant 2
System
Air Intake
Symptom
Power Loss / Black Smoke
Diagnosis & fix steps
LOGIC: Intake Manifold Boost Pressure Below Normal Operating Range.
ACTION: Inspect charge air cooler (CAC) boots for splits, check wastegate linkage travel, and verify boost pressure sensor line is free of soot accumulation.
Red Seal field insights
Physics: Air leak downstream of turbo causes incorrect air-fuel ratio, forcing ECM into derate to protect turbo from overspeeding.
Variant 3
System
Air Intake
Symptom
Power Loss / Black Exhaust Smoke
Diagnosis & fix steps
LOGIC: Intake Manifold Boost Pressure Below Normal Operating Range.
ACTION: Inspect charge air cooler (CAC) boots for splits, check wastegate linkage travel, and verify boost pressure sensor line is free of soot accumulation.
Red Seal field insights
Air Leak Physics: Air leaks downstream of the turbo cause an incorrect air-fuel ratio, forcing the ECM into derate to protect the turbo from overspeeding.
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