SPN 1761 FMI 4 is the Detroit code raised when the DEF tank level sender circuit has failed low, and this sheet walks the harness and Aftertreatment Control Module (ACM/ACM2.1) checks that isolate it. Follow it before replacing the sender.
Official document details
| Brand | Detroit |
| Model coverage | DD13, DD15, DD16 (EPA 2007-current) |
| System / group | DEF / SCR aftertreatment — level sensor circuit |
| Fault code | SPN 1761 / FMI 4 |
| Publication no. | Not printed on sheet |
| Year / revision | Reference dated 2017 |
| Pages | 1 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- Fault header: SPN 1761 / FMI 4 — DEF tank level sensor circuit failed low
- Monitored parameter and verification conditions
- Step 1 — disconnect and inspect the sender connector
- Step 2 — repair short to ground at ACM pin 109
SPN 1761 FMI 4 troubleshooting steps
This is a short one-page procedure. Step 1 disconnects the DEF tank temperature/level sender and Step 2 inspects its connector for bent, spread or corroded pins. If pin damage is found it is repaired; if the connector is clean, the fault is a short to ground between pin 1 of the sender and pin 109 of the Aftertreatment Control Module (ACM), which is repaired directly. The sheet lists the monitored parameter as the DEF tank level sensor, always enabled, with a typical two-second duration and MIL and CEL lamps.
Applicable truck models
This procedure covers Detroit DD-series engines — DD13, DD15 and DD16 on the EPA 2007-current platform with SCR aftertreatment — and shares its SPN/FMI structure with related Series 60 DDEC VI applications. Confirm the emissions calibration (EPA07, EPA10 or GHG14) before probing any pin. For engine serial-number and calibration confirmation, use the Detroit Diesel official support site.
Who needs the SPN 1761 FMI 4 manual
Diesel technicians and aftertreatment specialists use this sheet to test the DEF tank temperature/level sender wiring, distinguish a short or open from a failed sender, and identify the exact ACM pins before ordering parts.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download. Source: Detroit SPN/FMI fault-code reference (© 2017); circuit values are measured with the Detroit Diesel Diagnostic Link (DDDL) and a calibrated multimeter.
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