This DOC inlet temperature sensor sheet documents Detroit fault code SPN 4332 / FMI 31 on GHG14 engines, where a High Idle Regeneration is aborted because the Diesel Oxidation Catalyst inlet did not reach 270°C (518°F). The three-page procedure checks the sensor, the intake throttle and the exhaust for leaks.
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 4332 / FMI 31 |
| Fault name | DOC inlet temperature out of range low preventing dosing |
| Emissions platform | GHG14 |
| Pages | 3 |
| File size | 0.3 MB |
| Format | |
| Language | English |
| Source | TruckFaultCodes.com (© 2017); Detroit Power Service Literature |
DOC inlet temperature sensor sections covered
The routine first rules out related codes, then monitors the sensor at idle before testing the throttle and hunting for leaks.
- Meaning: HIR aborted below 270°C (518°F); MIL stays on
- Check for SPN 3242 FMI 8 or 20 first
- Monitor DOC inlet and outlet temperatures at 10-minute idle
- Run an Intake Throttle service routine
- Inspect the exhaust and pressurise the intake for leaks
- Perform a parked regen to verify the repair
Applicable truck models
These steps cover Detroit DD-Series (DD13, DD15 and DD16) and Series 60 DDEC VI engines on the GHG14 platform. Intake throttle and regeneration routines are described in Detroit Power Service Literature, reached from the Detroit Diesel official website.
Who needs this DOC inlet temperature sensor manual
This inlet temperature sensor manual is for the technician facing repeated aborted regenerations on SPN 4332 / FMI 31, where a drifted sensor, a stuck throttle or an exhaust leak can each block the temperature the burn needs.
The full 3-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 4332 / FMI 31 in Power Service Literature, and technicians should keep the wiring pin numbers shown in this sheet on hand while testing on the bench.
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