This Post Run Indicator Lamp sheet covers Detroit SPN 3490 FMI 5, set by a short circuit on pin 14 of the Aftertreatment Control Module (ACM2.1) 120-pin connector. It states the repair and the one condition under which the circuit exists. It is a short, wiring-only reference.
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | DD Series (EPA 2007-Current); also filed under Series 60 (DDEC VI – EPA 2007) |
| System / Group | DTCs — Post Run Indicator Lamp |
| Fault code | SPN 3490 / FMI 5 |
| Source | www.TruckFaultCodes.com (© 2017) |
| Pages | 1 |
| File size | 0.1 MB |
| Format | |
| Language | English |
Post Run Indicator Lamp diagnostic guide
The document indicates a short circuit on the pin 14 circuit of the ACM2.1 120-pin connector and directs the technician to repair that short, referring to Original Equipment Manufacturer (OEM) literature for the wiring schematic. A note limits the process lamp to trucks fitted with a negative battery disconnect system, so vehicles without that feature are not affected. No numbered troubleshooting steps are included; it is a targeted wiring repair reference.
Document table of contents
- Fault code identification: SPN 3490, FMI 5
- Description of the process lamp circuit
- ACM2.1 pin 14 short-circuit repair
- Negative battery disconnect system note
Applicable truck models
This procedure applies to Detroit DD Series engines built for EPA 2007 and later, covering GHG14 calibrations as printed on the document cover, and the identical SPN/FMI sheet is also filed under Detroit Series 60 (DDEC VI, EPA 2007). Confirm the emissions platform on your truck and cross-check the connector and pin numbers against the official Detroit engine support site before making any repair.
Who needs this Run Indicator Lamp manual
An aftertreatment or electrical technician on a GHG14 Detroit truck with negative battery disconnect uses this sheet to repair the correct ACM2.1 pin 14 branch instead of chasing the lamp elsewhere.
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