Kenworth SPN 102 FMI 10: Boost Pressure Diagnosis
SPN 102 FMI 10 (FMI 10) — Engine Intake Manifold #1 Pressure — Abnormal Rate of Change
Quick Answer
On Kenworth, SPN 102 FMI 10 is a Boost Pressure fault (Abnormal Rate of Change). Prove wiring/live data first; do not parts-cannon the component.
Overview: Kenworth SPN 102 FMI 10
On Kenworth, SPN 102 FMI 10 is a Boost Pressure fault (Abnormal Rate of Change). Prove wiring/live data first; do not parts-cannon the component. This guide covers symptoms, root causes, live-data checks, and misdiagnoses for Kenworth platforms.
Repair Snapshot
Time
1 - 3 Hours
Difficulty
Advanced
Parts Cost
$50 - $800
Dealer Labor
$350+
Tools Required
- PACCAR Davie
- Diesel Laptops
- Multimeter
What SPN 102 FMI 10 Means
SPN 102 FMI 10 on Kenworth means Engine Intake Manifold #1 Pressure — Abnormal Rate of Change. Confirm Smoke-test charge-air; compare MAP to mechanical boost with PACCAR Davie / Diesel Laptops before replacing the boost pressure.
Symptoms Drivers Notice
- Check-engine / amber warning lamp illuminated.
- Soft power, unstable idle, or poor response when boost pressure data is irrational.
- Live data for boost pressure fails rationality vs mechanical gauge or partner sensors.
- Codes may return immediately after clearing if root cause remains.
Most Likely Root Causes
Common Misdiagnoses (Don't Waste Parts)
Why it happens:
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Why it happens:
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Why it happens:
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Master Tech Commentary
Mechanic's Notes
Shop tip (Kenworth): For SPN 102 FMI 10, prove Smoke-test charge-air; compare MAP to mechanical boost before quoting the Boost Pressure. Common false path is replacing the sensor when the harness or reference circuit is the failure.
Step-by-Step Diagnostic Procedure
- Step 1: Connect PACCAR Davie or Diesel Laptops and record SPN 102 FMI 10 with freeze-frame load/temp.
- Step 2: Inspect harness and connector at the boost pressure for chafe, corrosion, and bent pins.
- Step 3: Verify 5V reference / ground / signal integrity with a multimeter where applicable.
- Step 4: Smoke-test charge-air; compare MAP to mechanical boost
- Step 5: Repair the proven fault, clear only after repair, and verify under the same conditions as freeze-frame.
Live Data & Freeze-Frame Tips
Log Boost Pressure with PACCAR Davie under freeze-frame conditions. Smoke-test charge-air; compare MAP to mechanical boost. Compare to a mechanical gauge when pressure/temperature related.
When to Limp In vs Tow
Drive carefully to a shop if lamps are warning-only and power remains controllable; tow if power loss is severe.
Related Fault Codes
Frequently Asked Questions
What does Kenworth SPN 102 FMI 10 mean?
It indicates a Boost Pressure fault: Abnormal Rate of Change. Confirm with live data and wiring tests before parts replacement.
Can SPN 102 cause a derate?
It can contribute to limp behavior if the ECM loses trust in critical data, especially when paired with other faults.
What tools diagnose this best?
PACCAR Davie and Diesel Laptops, plus a quality multimeter and mechanical gauges for pressure/temperature checks.
Should I clear the code first?
No. Capture freeze-frame and the full stack first. Clear only after the repair and verification.
More Kenworth codes on this system
- Kenworth SPN 2659 FMI 7 — Turbocharger Wastegate Actuator
- Kenworth SPN 108 FMI 3 — Barometric Pressure Sensor
- Kenworth SPN 91 FMI 3 — Accelerator Pedal Position Sensor Circuit
- Kenworth SPN 110 FMI 0 — Engine Coolant Temperature Sensor
- Kenworth SPN 3251 FMI 2 — DPF Differential Pressure Sensor
- Kenworth SPN 100 FMI 1 — Engine Oil Pressure Sensor
- Kenworth SPN 168 FMI 0 — Battery / Charging System Circuit
- Kenworth SPN 646 FMI 7 — Turbocharger Wastegate Drive
Guides that go deeper
- SPN 1569 FMI 31: Engine Protection Shutdown and Safe Recovery Steps [2026 Diagnostic Guide]
SPN 1569 FMI 31 means engine protection shutdown is active—not the root fault. Read stacked codes, verify oil and coolant, then reset only after the trigger is fixed.
- Detroit DDDL Basics: Finding the Root Code Behind a Derate
Use Detroit DDDL the right way: separate root SPN/FMI faults from inducement result codes, read derate stage data, and stop replacing parts on guesses.
- How to Capture a Useful Fault Stack Before the Shop Clears Codes
How drivers and techs can capture a useful fault stack—SPNs, FMIs, freeze-frame, and counts—before anyone clears codes and erases the diagnosis.