P24A1: DPF regeneration temperature exceeds its target

P24A1 is the high-temperature side of the DPF regeneration control-error diagnosis. The monitored quantity is target minus measured temperature. A result below −100°C means the measured value exceeds its target by more than 100°C in this calibration.

Steady-state regeneration only

Unlike P24A0, which includes warm-up logic, this entry runs only during steady-state regeneration with closed-loop temperature control enabled. It uses 850 failures out of 1,000 samples at a 100 ms task rate and Type B, two-trip reporting. Supporting conditions must remain qualified for more than five seconds before assessment.

The selected temperature point depends on aftertreatment architecture. Exhaust-flow validity, sensor or model health, engine operating point and flow stability also qualify the check. Consequently, a single absolute exhaust temperature is not enough to reproduce the decision.

Diagnostic interpretation

Retain the control target, selected measured temperature and regeneration state. A temperature that would be acceptable under one target can represent excessive overshoot under another. Ensure the correct architecture's sensor or model is being evaluated before drawing conclusions.

Verification needs a completed steady-state control comparison with acceptable error. The source does not identify an injector, catalyst or sensor as the proven cause. Do not initiate uncontrolled regeneration or approach hot exhaust based on the code alone; use the prescribed professional service procedure.

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 1486. GM diagnostic parameters, PDF page 1487. GM diagnostic parameters, PDF page 1488.