This DEF injection valve circuit guide is the Detroit DD Series SPN 3597 FMI 4 fault-code procedure for EPA10 engines, where proportional valve bank 1 reads failed low. It isolates a short across the shared high-side supply that feeds the aftertreatment dosing components.
Official document details
| Brand | Detroit |
| Model coverage | Detroit DD Series (EPA 2007-Current) |
| System / group | DD Series / DTCs |
| SPN | 3597 |
| FMI | 4 |
| Condition | proportional valve bank 1 circuit failed low |
| Emissions level | EPA10 |
| Source | Detroit Power Service Literature |
| Pages | 2 |
| File size | 0.2 MB |
| Format | |
| Language | English |
DEF injection valve circuit checks
A note in the document explains that this supply feeds the Diesel Exhaust Fluid pump, metering unit, diffuser heater and the injection valve. You disconnect those components, inspect the connectors for bent, spread or corroded pins, then clear codes and reconnect one component at a time. If the fault stays active with the ACM2 unplugged the module is replaced; otherwise the offending component or a short to ground at ACM2 pins 1, 3 or 5 is repaired.
- Fault description: proportional valve bank 1 circuit failed low
- Note on the shared high-side supply components
- Steps 1 to 2 – Disconnect components and inspect pins
- Steps 3 to 6 – Clear codes and test with ACM2 unplugged
- Step 7 – Reconnect components one at a time
Applicable truck models
This EPA10 fault code applies to Detroit DD Series diesel engines whose Diesel Exhaust Fluid components share a supply from the ACM2 aftertreatment module. Component locations follow Detroit Power Service Literature; verify them on the official Detroit Diesel website.
Who needs this DEF injection valve circuit manual
Diesel technicians and workshop owners chasing a shared-supply short on an EPA10 Detroit engine use this document to reconnect the DEF pump, metering unit, diffuser heater and injection valve in turn and find the failed part.
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