The Cummins M11 code 143 sheet documents the oil pressure engine protection circuit (PID P100, SPN 100, FMI 1) on Cummins CELECT engines built from 1990 to 1994. This 2-page reference drives a technician through the circuit description, oil pressure sensor location, and the pin-by-pin checks needed to turn the engine protection or red lamp off.
Official document details
| Brand | Cummins |
| Model coverage | M11 and N14 CELECT (1990-94) |
| System / Group | Oil pressure — engine protection |
| Fault code identifier | Code 143 · PID P100 · SPN 100 · FMI 1 · SRT 00-057 |
| Warning lamp | Engine Protection or Red |
| Pages | 2 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- Circuit description
- Component location on M11 and N14
- Shop talk on engine speed under load
- Mechanical gauge verification
- Troubleshooting Steps 1A to 2B
- Clearing inactive fault codes
Applicable truck models
This procedure applies to Cummins M11 CELECT engines built from 1990 to 1994 and shares the oil pressure sensor logic used on N14 CELECT engines of the same era. It is a fault-code troubleshooting sheet from the CELECT diagnostic set (SRT 00-057), not a full engine manual, so confirm exact wiring and part numbers against factory data on the official Cummins website before replacing any component.
Cummins M11 code 143 diagnostic steps
Because this is an engine protection fault, first verify the reading rather than the wiring: connect a mechanical oil pressure gauge and a diagnostic tool, start the engine, and compare the gauge with the service-tool oil pressure value, raising engine speed to make differences visible. If the sensor reading is correct, clear and monitor the code; if it does not match, the sensor is suspect and troubleshooting moves to Fault Code 141. Confirm the sensor supply is 4.75 to 5.25 VDC using breakout cable Part Number 3824775.
Who needs this Cummins M11 code 143 manual
Technicians investigating low-oil-pressure warnings use this sheet to confirm whether the alarm reflects a real pressure drop under load or a faulty sensor before tearing into the base engine.
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Applies to these truck models
This is the manufacturer document shared across 2 model families. It applies to:
- Cummins DTCs
- Cummins M11 CELECT (1990-94)
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