Detroit DD13 EPA07 (2007-09) Fault Code: SPN 3242 FMI 2 (MCM) Diesel Oxidation Catalyst Inlet Temperature Sensor Circuit Plausibility Error

Posted by PerDiezel Solutions on March 8, 2026

NOTE: If any other codes are active, fix those first.

PROBABLE CAUSES:
1. Check all connectors/harnesses upstream of the MCM (DOC inlet temp sensor, ATD harness 10-pin connector, VIH 13-pin connector, MCM 120-pin connector).
2. DOC inlet temperature sensor.
3. DOC inlet temperature sensor connector/harness.
4. DPF inlet pressure sensor.
5. DPF inlet pressure sensor connector/harness.
6. DPF outlet pressure sensor.
7. DPF outlet pressure sensor connector/harness.
8. DPF plugged or has contamination (coolant, oil).
9. DOC failure.
10. Charge air cooler failure.
11. Intake manifold pressure sensor.
12. Intake manifold pressure sensor connector/harness.
13. Exhaust system leaks.
14. Turbocharger failure.
15. Fuel pressure out of spec (70-80 PSI).
16. Fuel doser injector valve failure.
17. DPF failure.
18. Perform a stationary regen.

WARNING!