SPN 524285 FMI 4 is a Detroit DD Series diagnostic fault-code sheet that documents the J1939 CM1 DPF Regeneration Switch Short Circuit to Ground condition and its factory troubleshooting sequence. The sheet lists the SPN and FMI identifiers, a short description of the condition, and the repair steps in the order Detroit recommends. It is a concise reference sheet, 1 page long, aimed at technicians who read the code with a scan tool and need to know the correct next step.
SPN 524285 FMI 4 troubleshooting overview
This sheet covers a J1939 CM1 DPF regeneration switch short circuit to ground. The procedure first has the technician connect a diesel diagnostic tool and check for related Common Powertrain Controller (CPC4) battery-voltage codes (SPN 168) and Motor Control Module (MCM2.1) SPN 625 codes, then confirm CPC4 configuration and module communication status.
Official document details
| Brand | Detroit (Detroit Diesel) |
| Model coverage | DD Series (EPA 2007-Current) |
| System / group | Diagnostic Trouble Codes (DTCs) |
| SPN | 524285 |
| FMI | 4 — J1939 CM1 DPF Regeneration Switch Short Circuit to Ground |
| Source | TruckFaultCodes.com fault-code reference (Copyright 2017) |
| Pages | 1 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification: SPN and FMI header
- J1939 CM1 DPF regeneration switch short-circuit-to-ground description
- Step 1: check for CPC4 SPN 168 and MCM2.1 SPN 625 codes with the diesel diagnostic tool
- Step 2: verify CPC4 configuration and Controller Area Network (CAN) communication
Applicable truck models
This code sheet applies to Detroit DD Series engines (DD13, DD15 and DD16) built to GHG14 emissions specifications under the EPA 2007-Current platform, and Detroit cross-lists it under both the DD Series and Series 60 (DDEC VI, EPA 2007) diagnostic trees. For factory service literature and warranty details, refer to the official Detroit Diesel website.
Who needs this SPN 524285 FMI 4 manual
This reference is written for technicians diagnosing J1939 datalink and DPF regeneration switch faults who need the CPC4 and MCM2.1 communication checks. Keep the 524285 FMI 4 sheet on hand so the code can be diagnosed and verified before it is cleared.
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