SPN 91 FMI 10 is the Detroit fault code for a data abnormal rate of change on the DD Series accelerator pedal circuit. This 2-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 | 91 |
| Failure Mode Identifier | 10 |
| Description | Data Abnormal Rate of Change |
| Coverage / Revision | GHG14 |
| Pages | 2 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification and description
- Accelerator Pedal (AP) harness voltage checks
- Common Powertrain Controller (CPC) circuit checks
- AP resistance and continuity checks
- Clearing codes and verifying the repair
SPN 91 FMI 10 diagnostic overview
SPN 91 FMI 10 covers an accelerator pedal abnormal-rate-of-change fault. The technician disconnects the AP, measures the B-to-C supply voltage, traces any open circuit to CPC #1 pins 4 and 8, then verifies pin A to pin 7 resistance is within limits before replacing the pedal. 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 library also carries the matching guide for the Series 60 (DDEC VI) platform. For factory support tools and warranty information, see Demand Detroit official resources.
Who needs this 91 FMI 10 manual
This document is aimed at Detroit DD Series technicians who want to separate a genuine pedal fault from harness or connector problems before ordering parts.
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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