SPN 157 FMI 2 is a Detroit™ fuel-pressure sensor diagnostic fault code, and this 1-page Detroit DD Series PDF documents the “Erratic Fuel Rail Pressure Sensor Signal” condition in full. This single-page EPA07 sheet addresses an erratic fuel rail pressure sensor signal. The fix is driven by the Motor Control Module software level: below 13.2 it is updated, and at or above 13.2 the case is escalated to software support. The summary below sets out the official causes, tools and troubleshooting order so a technician can verify the code before downloading the complete manual.
Official document details
| Brand | Detroit |
| Model coverage | DD Series (EPA 2007-Current) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Publication no. | Not printed on sheet (Detroit™ via TruckFaultCodes.com, © 2017) |
| Year / Revision | 2017 |
| Pages | 1 |
| File size | 0.2 MB |
| Format | |
| Language | English |
SPN 157 FMI 2 document contents
- Fault code identification (SPN and FMI)
- MCM software-level check
- Software update to 13.2 or higher
- Verify repair or escalate to software support
Applicable truck models
The procedure applies to Detroit DD Series diesel engines on the EPA07 emissions platform. It requires only the diagnostic tool to read and update Motor Control Module software. For factory service data, wiring diagrams and bulletins beyond this fault-code sheet, consult the official Detroit Diesel support site.
Who needs this SPN 157 FMI 2 manual
Technicians seeing an erratic rail-pressure signal on an EPA07 Detroit engine need this sheet to check software before replacing the sensor. It saves parts by pointing at a known calibration fix first.
The routine has you read the MCM software level, update it to 13.2 or higher and verify the repair, or, if the level is already current, call the diagnostic software support line for further help.
The full 1-page PDF is available in the DiagTechPro manuals library; a free account is required to download it. Every document in the library is indexed by suspect parameter number and failure mode identifier, so you can cross-reference related Detroit DD Series fault codes without leaving the page.
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