3242 FMI 3 EPA07 is the Detroit DD Series fault-code procedure for a diesel oxidation catalyst inlet temperature circuit failed-high fault. This 3-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) | 3 |
| Emission family | EPA07 calibration |
| Source | Detroit Power Service Literature (Copyright © 2017) |
| Pages | 3 |
| File size | 0.26 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification (fault 3242, failure mode 3)
- Troubleshooting steps
- Multiple-code check and turbocharger inlet air sensor
- DOC inlet sensor resistance and voltage 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 3 EPA07 manual
Diesel technicians, fleet workshops and mobile mechanics diagnosing a DOC inlet temperature circuit failed-high code 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 3 EPA07 repair steps explained
Because the EPA07 sensors share a supply, the procedure first checks whether related codes are present alongside SPN 3250/FMI 3, SPN 3246/FMI 3 and SPN 1172/FMI 3; if so, the turbocharger inlet air temperature sensor and pin 88 of the Motor Control Module (MCM) 120-pin connector are tested for a short to power or an open. The DOC inlet temperature sensor resistance is measured between pins 1 and 2 against the published table, and the connector voltage should read between 2.75 and 3.25 volts. Out-of-range sensors are replaced per Detroit Power Service Literature.
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