This ACM 5V sensor supply sheet covers Detroit SPN 3509 FMI 3 on the Aftertreatment Control Module, set when the reference reads a short to power. It walks through the diesel oxidation catalyst (DOC) inlet pressure sensor circuit and its wiring back to the ACM. Use it to place the short precisely.
Official document details
| Brand | Detroit |
|---|---|
| Model coverage | DD Series (EPA 2007-Current); also filed under Series 60 (DDEC VI – EPA 2007) |
| System / Group | DTCs — 5V Sensor Supply Bank 1 Circuit Failed High |
| Fault code | SPN 3509 / FMI 3 |
| Source | www.TruckFaultCodes.com (© 2017) |
| Pages | 2 |
| File size | 0.2 MB |
| Format | |
| Language | English |
ACM 5V sensor supply diagnostic guide
With the ignition on, the technician disconnects the DOC inlet pressure sensor and inspects the harness pins for damage. Measuring pin 3 to ground against a 5.5 volt threshold decides whether the short to battery lies on the pin 3 branch to ACM pin 117 or on the pin 1 branch to ACM pin 88. A note warns that DPF outlet pressure (SPN 3610) and DPF inlet pressure (SPN 3609) faults may appear alongside it, so related codes are read before repair.
Document table of contents
- Fault code identification: SPN 3509, FMI 3
- Description, monitored parameter and enabling conditions
- DOC inlet pressure sensor circuit checks
- Short-to-battery repair at ACM pins 117 and 88
- Related DPF pressure fault note
Applicable truck models
This procedure applies to Detroit DD Series engines built for EPA 2007 and later, covering EPA10 and 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 ACM 5V sensor supply manual
An aftertreatment technician on an EPA10 or GHG14 Detroit engine uses this sheet to isolate a shorted reference at the DOC inlet pressure sensor and its ACM wiring rather than replacing the catalyst assembly blindly.
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