SPN 105 — Intake Manifold #1 Temperature
System: Air intake
Temperature of the air entering the cylinders after the charge air cooler.
Can I keep running it?
MEDIUM — fix soon
High intake temps reduce power and can lead to a derate. Drivable with care.
Likely causes
- Dirty or blocked charge-air cooler fins
- Charge-air cooler leak
- Fan not engaging
- EGR cooler problem raising intake temperature
- Sensor or wiring fault
Checks & fixes (easiest first)
- Clean the CAC and radiator stack
- Verify fan engagement
- Pressure-test the CAC
- Compare the sensor to ambient after a cold soak
Common FMIs with SPN 105
- SPN 105 FMI 0Value too high (most severe)
- SPN 105 FMI 2Data erratic, intermittent, or incorrect
- SPN 105 FMI 3Voltage above normal or shorted high
- SPN 105 FMI 4Voltage below normal or shorted low
- SPN 105 FMI 15Value too high (least severe)
- SPN 105 FMI 16Value too high (moderately severe)
Related codes
FAQ
What does SPN 105 mean?
SPN 105 is Intake Manifold #1 Temperature. Temperature of the air entering the cylinders after the charge air cooler.
Can I keep running with SPN 105?
High intake temps reduce power and can lead to a derate. Drivable with care.
What causes SPN 105?
Dirty or blocked charge-air cooler fins; Charge-air cooler leak; Fan not engaging; EGR cooler problem raising intake temperature; Sensor or wiring fault.