Diesel Particulate Filter DTC P2459 - keywords 07 08 6.6L DTC engine exhaust LMM regen regeneration SES tow towing

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A dealer may encounter a 2007 6.6 Duramax Diesel Engine setting DTC P2459 for Diesel Particulate Filter Regeneration Too Often. P2459 may occur more often on vehicles that tow heavy loads on a regular basis.

If P2459 is the only DTC set, complete the current SI diagnostics for P2459. If diagnostics are inconclusive please do not attempt repairs.

Engineering is investigating a updated calibration for P2459 when it sets by itself.

Please review the DPF operation found in the owners manual (SI document id number 1819641) with the customer.

Also document the DPF regeneration data found below on the work order.

Total number of DPF regenerations

Distance since last DPF regeneration

Fuel used since last DPF regeneration

Engine run time since last DPF regeneration

This PI will be updated when new information becomes available

Note: Any driveability symptom or DTC that induces excessive exhaust smoke may occur along with P2459. If a vehicle has other driveability symptoms or DTCs, and they are occurring along with P2459, diagnose those DTCs/symptoms using the current SI diagnostics. Make repairs as necessary and re-evaluate if the P2459 resets.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.