P24A0: DPF regeneration temperature remains below its target

P24A0 monitors temperature-control error during particulate-filter regeneration. The source compares a control target with the relevant measured temperature downstream of the close-coupled oxidation catalyst or upstream of the DPF, depending on architecture. A positive target-minus-measured error above 100°C is the documented low-temperature criterion.

Warm-up and steady-state paths differ

The entry contains both regeneration warm-up and steady-state logic. The warm-up path requires its enabling conditions for more than 150 seconds; the steady-state path requires more than five seconds. Both use 850 failed samples out of 1,000 at a 100 ms task rate. Reporting is Type B, two trips.

Closed-loop temperature control must be enabled. Valid supporting temperature and exhaust-flow information, qualified engine operating points and suitable flow conditions are also required. This is therefore not an ordinary low-temperature check during any engine operation.

Interpreting the shortfall

Compare target, actual temperature and regeneration state together. A measured temperature can be high in absolute terms yet remain too far below its requested target. Equally, a cold exhaust outside regeneration does not reproduce the monitor.

Verification should confirm a completed control-error assessment in the appropriate state. The table does not identify which heat-generation or measurement mechanism caused the shortfall. Regeneration involves hot exhaust and should follow the vehicle's professional service procedure, not a drive recipe inferred from this summary.

Source and application limits

This explanation covers the cited 2025 GM monitor. Confirm the vehicle and calibration in its service information before applying these limits; inclusion in this file does not establish model compatibility. GM diagnostic parameters, PDF page 1482. GM diagnostic parameters, PDF page 1483. GM diagnostic parameters, PDF page 1484. GM diagnostic parameters, PDF page 1485.