Caterpillar Fault Code

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SPN 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.

Same code keeps coming back?

That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.

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Read before you touch anything

  • This is general reference information, not a repair manual. It is for trained, qualified technicians.
  • Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
  • Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
  • You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
  • Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.

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