The Cummins M11 121 sheet documents the engine position sensor circuit (PID 190, SPN 190, FMI 10) on Cummins CELECT engines built from 1990 to 1994. This 8-page reference drives a technician through the circuit description, engine position sensor location, and the pin-by-pin checks needed to turn the yellow lamp off.
Cummins M11 121: Official document details
| Brand | Cummins |
| Model coverage | M11 and N14 CELECT (1990-94) |
| System / Group | Engine position sensor (EPS) circuit |
| Fault code identifier | Code 121 · PID 190 · SPN 190 · FMI 10 · SRT 00-081 |
| Warning lamp | Yellow |
| Pages | 8 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Document table of contents
- Circuit description
- Component location on M11 and N14
- Shop talk on camshaft end play
- Sensor short-to-ground and coil checks
- Sensor removal with installation tool
- Pinout and continuity checks
- Troubleshooting Steps 1A to 3B
Applicable truck models
This procedure applies to Cummins M11 CELECT engines built from 1990 to 1994 and shares the engine position sensor logic used on N14 CELECT engines of the same era. It is a fault-code troubleshooting sheet from the CELECT diagnostic set (SRT 00-081), 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 121 diagnostic steps
Clean and inspect the sensor connector with electronic contact cleaner Part Number 3824510, then check each engine position sensor pin for a short to ground above 10M ohms. Remove the sensor with installation tool Part Number 3822747 and inspect its tip for metal debris or camshaft damage. Measure the internal coils (pin A to D and B to C read 1000 to 2000 ohms; A to B reads above 10M ohms), then verify the harness pinout — red to D-14, black to A-11, white to B-15, green to C-1 — before clearing the code.
Who needs this Cummins M11 121 manual
Technicians diagnosing rough running or a no-start with no engine-speed reading use this sheet to test the engine position sensor and its harness against exact resistance and pinout values.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download.
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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