This Cummins Top2 transmission circuit guide covers Fault Code 544 (PID S191, FMI 7) on the M11 CELECT Plus, where a mechanical system failure is reported in the autoshift control. The 9-page yellow-lamp document walks through the shift and lockout solenoid checks.
Official document details
| Brand | Cummins |
|---|---|
| Model coverage | M11 CELECT Plus (1995-98) |
| System / group | Top2 Transmission Circuit – Mechanical System Failure |
| Fault code | 544 |
| PID / SPN | S191 |
| FMI | 7 |
| Diagnostic lamp | Yellow |
| Pages | 9 |
| File size | 0.4 MB |
| Format | |
| Language | English |
| Source | Cummins fault code reference (TruckFaultCodes.com, 2017) |
Document table of contents
- Circuit description
- Component location
- Shop talk diagnostic notes
- Step-by-step troubleshooting
- Fault verification and clearing codes
Cummins Top2 transmission circuit coverage
The Top2 transmission circuit lets the ECM autoshift a Top2 transmission between its gears through top-mounted shift and lockout solenoids near the back of the transmission. The document’s shop talk warns that Code 544 with a driver complaint of rpm surge appears when a Top2 calibration is loaded into a non-Top2 application, so the technician is told to check the ESDN comments field for the calibration and confirm the truck actually has a Top2 transmission. Troubleshooting then covers the lockout and shift solenoid click tests, 12 VDC checks at the OEM connector, and continuity through the 21-pin Deutsch connector using diagnostic tool part number 3824638.
Applicable truck models
It applies to Cummins M11 CELECT Plus (1995-98) engines paired with a Top2 automated transmission. Wiring can vary, so verify solenoid connector pinouts against the official Cummins website.
Who needs this Top2 transmission circuit manual
Drivetrain technicians chasing autoshift faults, rpm surge complaints, or suspected calibration mismatches on M11-powered trucks rely on this step chart.
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 Plus (1995-98)
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