Cummins M11 code 422 is the Cummins troubleshooting document for the Coolant Level Sensor Circuit fault (PID P111, SPN 111, FMI 2, SRT 00-610). The coolant level sensor monitors the coolant level in the cooling system and passes the information to the ECM through the sensor harness; it is an OEM-controlled sensor located in the radiator top tank or surge tank. It sets a yellow warning lamp and lists the exact conditions, causes, and step-by-step checks a technician follows.
Official document details
| Brand | Cummins |
|---|---|
| Model coverage | Cummins M11 CELECT electronic engines built 1990 to 1994 |
| System / Group | M11 CELECT (1990-94) |
| Fault identifiers | PID P111, SPN 111, FMI 2, SRT 00-610 |
| Warning lamp | Yellow |
| Pages | 5 |
| Format | |
| Language | English |
Document table of contents
- Circuit description
- Component location
- Shop Talk
- Step-by-step troubleshooting steps
- Fault code clearing and verification
Trucks covered by Cummins M11 code 422
This procedure applies to Cummins M11 CELECT electronic engines built 1990 to 1994. The procedure carries the Cummins fault identifiers PID P111, SPN 111, FMI 2, SRT 00-610 for reference and repair-time tracking. It is set by the coolant level dropping below a set point, or a wiring fault in the OEM-controlled coolant level circuit, and typical effects include a progressive power derate that increases with time after the alert. For engine specifications and dealer support, see the official Cummins website.
Who needs this Cummins M11 code 422 manual
Heavy-truck technicians, fleet maintenance teams, and workshop owners diagnosing this fault use it to confirm the code before replacing parts. During diagnosis a multimeter must not be used to check the coolant level sensor, and the OEM must be consulted for the specific pinouts on the 9-pin Deutsch connector. The step-by-step tree starts by reading active and inactive codes with the diagnostic tool, then inspects the harness and connector pins for bent, corroded, pushed-back, or expanded pins, flushing them with electronic contact cleaner Part Number 3824510 before any component is condemned. Test leads run around the bulkhead are used to isolate a faulty OEM harness, and the code is rechecked and cleared once the repair passes.
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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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