Cummins fault code 351 is the Cummins ISM CM871 (2007-09) diagnostic reference for Injector Power Supply – Bad Intelligent Device or Component, reported as PID S251, SPN 627, FMI 12/12 with an Amber lamp. This 4-page workshop PDF covers the Injector Power Supply Circuit (ISM), giving the fault description, shop-talk notes, component location and the step-by-step troubleshooting tree. It is compiled from the TruckFaultCodes.com fault-code library (Copyright © 2017).
Official document details — Cummins fault code
| Brand | Cummins |
| Model coverage | ISM and ISX CM871 (2007-09) engines |
| System / Group | Injector Power Supply Circuit (ISM) / DTCs |
| Fault identifiers | PID S251, SPN 627, FMI 12/12, Amber lamp |
| Source | TruckFaultCodes.com fault-code library (© 2017) |
| Pages | 4 |
| File size | 0.27 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code header (PID, SPN, FMI, lamp)
- Description
- Shop Talk
- Component Location
- Troubleshooting Steps
Reading Cummins fault code 351
Between injection events the ECM recharges the injector power supply, a bank of capacitors held at high voltage, by recovering energy from the injector solenoids; keeping it charged requires good ECM battery power and ground, a good engine speed sensor and good injector circuits.
The Cummins Shop Talk section advises confirming the ECM calibration is correct and recalibrating if necessary. Documented possible causes include:
- weak ECM battery power or ground
- a faulty engine speed sensor signal
- injector circuit faults that prevent the supply reaching commanded voltage
Component location manual information
The injector power supply is located inside the ECM.
Applicable truck models
This document applies to Cummins ISM CM871 (2007-09) engines, and the same circuit description is shared with the ISX CM871 platform where noted in the extract. These engines power many Class 8 highway tractors and vocational trucks built by North American OEMs. Confirm the exact ECM calibration and OEM wiring against the manufacturer records; full engine support is published by Cummins official engine support.
Who needs this Cummins fault code 351 manual
Fleet technicians, independent diesel mechanics and workshop owners diagnosing an active injector power supply condition will use this sheet to follow the correct troubleshooting order instead of replacing parts on guesswork.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it.
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