3242 FMI 4 EPA07 is the Detroit DD Series fault-code procedure for a diesel oxidation catalyst inlet temperature sensor failed-low fault. This 2-page diagnostic PDF documents the fault, its monitored circuit on the diesel oxidation catalyst (DOC) inlet temperature sensor, and the exact troubleshooting steps a technician follows to confirm and repair the failure.
Official document details
| Brand | Detroit |
| Model coverage | DD Series (EPA 2007-Current); Series 60 DDEC VI |
| System / Group | DD Series / DTCs |
| SPN (fault code) | 3242 |
| FMI (failure mode) | 4 |
| Emission family | EPA07 calibration |
| Source | Detroit Power Service Literature (Copyright © 2017) |
| Pages | 2 |
| File size | 0.24 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification (fault 3242, failure mode 4)
- Troubleshooting steps
- Sensor and MCM connector inspection
- Aftertreatment harness and resistance checks
Applicable truck models
This procedure applies to Detroit DD13, DD15 and DD16 engines in the DD Series (EPA 2007-Current) range and the equivalent Series 60 (DDEC VI) platform, as fitted to Freightliner and Western Star trucks. Confirm the EPA07 emission family matches the truck before following the steps; full model and coverage data is published on the Detroit official website.
Who needs this 3242 FMI 4 EPA07 manual
Diesel technicians, fleet workshops and mobile mechanics diagnosing a DOC inlet temperature sensor reading failed low on EPA07 Detroit engines need this reference to test the circuit correctly with a diesel diagnostic tool instead of replacing parts by guesswork.
3242 FMI 4 EPA07 repair steps explained
With the ignition off, the technician disconnects the DOC inlet temperature sensor and the Motor Control Module (MCM) 120-pin connector and inspects both for bent, pushed-out, spread or corroded pins. Resistance from pin 2 on the harness side to battery ground below 1K ohm shows a short to ground in the wire to pin 89 of the MCM. The 14-way or 31-way aftertreatment connectors and intermediate chassis wiring are inspected for abrasion, and the sensor is replaced per Detroit Power Service Literature after the previous steps are reviewed.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it.
Related manuals library
