Detroit VSS FMI 13 is the Detroit fault code for a j1939 wheel-based vehicle speed signal from source #1 is missing on the DD Series wheel-based vehicle speed sensor circuit. This 1-page reference from the DiagTechPro library reproduces the official Detroit troubleshooting steps so a technician can work the fault in the correct order. It is a factory-style diagnostic guide, not a repair shortcut.
Official document details
| Brand | Detroit (Detroit Diesel) |
| Model coverage | DD13, DD15, DD16 – DD Series (EPA 2007–current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Suspect Parameter Number | 84 |
| Failure Mode Identifier | 13 |
| Description | J1939 Wheel-Based Vehicle Speed Signal From Source #1 Is Missing |
| Coverage / Revision | EPA07 / GHG14 |
| Pages | 1 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification and description
- Checking for multiple related fault codes
- CPC battery and MCM CAN checks
- CPC reprogramming and configuration review
- ServiceLink module communication checks
Detroit VSS FMI 13 diagnostic overview
Detroit VSS FMI 13 is set when the J1939 wheel-based vehicle speed signal from source #1 is missing on EPA07 and GHG14 trucks. The technician checks for CPC SPN 168 battery faults and MCM SPN 625/FMI 9, confirms the CPC configuration, then uses ServiceLink to trace the source module. It also references Detroit DiagnosticLink (DDDL 7.x) and ServiceLink for reading module configuration and communication status. Each step is written as a yes or no decision, so the result of one measurement points directly to the next check or to the final repair action.
Applicable truck models and engines
It applies to Detroit DD13, DD15 and DD16 engines in the DD Series (EPA 2007 to current) family, and the same code is documented for the Series 60 (DDEC VI) platform. Vehicle speed can be hardwired to the Common Powertrain Controller or transmitted over J1939, so the guide points to the Application and Installation manual and OEM literature for chassis wiring. For factory support tools and warranty information, see Demand Detroit official resources.
Who needs this Detroit VSS FMI 13 manual
This document suits Detroit DD Series technicians who need the source #1 J1939 troubleshooting path for a missing wheel-based speed signal.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it, view every page, and print the decision steps for use at the workshop bench.
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