NOTE: The fault indicates that the High Idle Regeneration (HIR) was aborted due to the Diesel Oxidation Catalyst (DOC) inlet temperature not reaching the minimum of 270°C (518°F) to initiate dosing during an HIR. The CEL and MIL lamps will remain ON until the fault is resolved or a successful regeneration is completed.

NOTE: Please see the step by step troubleshooting procedures for this specific code.

NOTE: If codes 3242-xx exist, fix those first.

PROBABLE CAUSES:
1. Intake throttle valve failure.
2. Exhaust leaks.
3. Intake manifold leaks.
4. Charge air cooler leaks.
5. Jake brake operation (Not turning on).
6. DOC inlet temperature sensor.
7. ECM failure.
8. Jack brake rocker arm shaft not installed properly or failed.