This Detroit oil pressure sensor reference documents fault code SPN 100/FMI 4 (Engine Oil Pressure (EOP) Sensor Circuit Failed Low) for Detroit DD-series engines with the EOP sensor on the MCM harness. It reproduces the original TruckFaultCodes.com fault tree, from the first check through the final repair, so the code can be confirmed and worked in the exact order the factory intended. Each step lists the measured value or check and the pass or fail branch that follows, matching the layout used in the source document.
Detroit oil pressure sensor troubleshooting overview
This circuit-failed-low tree isolates the engine oil pressure (EOP) sensor wiring. It checks for companion FMI 4 codes, inspects the connector, verifies the 4.5 to 5.5 V supply on pin 3, then measures the signal, ground and short paths to MCM pins 54, 82 and 105. Depending on the reading it directs a harness repair or replacing the sensor. Follow the checks in sequence and verify the repair before clearing the code and releasing the vehicle.
Official document details
| Brand | Detroit |
| Model coverage | Detroit DD-series engines with the EOP sensor on the MCM harness |
| System / group | DTCs — engine oil pressure (EOP) sensor circuit |
| Fault code | SPN 100/FMI 4 |
| Source publication | TruckFaultCodes.com (© 2017) |
| Pages | 4 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification — SPN 100/FMI 4
- Check for companion FMI 4 circuit codes
- EOP connector inspection and 5 V supply check (pin 3)
- Signal-wire check to MCM pin 105; ground and short checks
- Harness repairs to MCM pins 54, 82 and 105; replace the EOP sensor
Applicable truck models
It applies to Detroit DD-series engines with the EOP sensor on the 120-pin MCM harness shared with the camshaft-position and fuel-pressure sensors. Always cross-check the reading against any companion codes before condemning a component. For the official product and service literature, visit the Detroit Diesel website.
Who needs this Detroit oil pressure sensor manual
Technicians who need the exact voltages and MCM pin numbers to repair an EOP circuit failed low. It is written for shop use as a quick, printable reference to keep beside a diesel diagnostic tool during the job.
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