This Detroit pressure limiting unit sheet documents fault code SPN 4336 / FMI 4 on EPA10 engines, a circuit-failed-low condition with a 25% derate. The procedure disconnects the ACM2 and measures resistance to ground to split a shorted wire from a failed component.
Official document details
| Brand | Detroit |
| Model coverage | Detroit DD-Series (DD13, DD15, DD16) and Series 60 (DDEC VI) |
| System / Group | DD Series (EPA 2007-Current) / DTCs |
| Fault code | SPN 4336 / FMI 4 |
| Fault name | Pressure limiting unit circuit failed low |
| Emissions platform | EPA10 |
| Pages | 2 |
| File size | 0.2 MB |
| Format | |
| Language | English |
| Source | TruckFaultCodes.com (© 2017); Detroit Power Service Literature |
Detroit pressure limiting unit sections covered
The two-page routine turns the key off, inspects the connector and runs a single resistance-to-ground check.
- Monitored parameter and 25% engine derate; MIL and CEL
- Turn the ignition off and disconnect the harness connector
- Inspect the harness for bent, spread or corroded pins
- Disconnect the ACM2 120-pin connector
- Measure resistance to ground (less than 1K ohms)
- Repair the wire to ACM2 pin 26, or replace the unit
Applicable truck models
The sheet applies to Detroit DD-Series (DD13, DD15 and DD16) and Series 60 DDEC VI engines on the EPA10 aftertreatment platform using the ACM2 control module. Component removal is documented in Detroit Power Service Literature, linked from the Detroit Diesel official website.
Who needs this pressure limiting unit manual
This pressure limiting unit manual guides a workshop through SPN 4336 / FMI 4, confirming whether the low circuit is a wiring short to ground or a failed unit before the 25% derate can be cleared.
The full 2-page PDF is available in the DiagTechPro manuals library; a free account is required to download. For workshop reference, Detroit documents the matching component removal and installation steps for SPN 4336 / FMI 4 in Power Service Literature, and technicians should keep the wiring pin numbers shown in this sheet on hand while testing on the bench.
Related manuals library
