P0602: programming status depends on which module reports it

P0602 identifies a control-module programming problem, but the documented trigger differs by module. The ECM example is narrow: a service replacement controller remains in its unprogrammed service-calibration state. The EBCM example includes calibration and configuration checks associated with the brake-control system.

ECM and brake-controller meanings

The ECM tests at powerup and then once per second. The fact that a replacement controller communicates is therefore not proof that the required vehicle programming has been completed; communication and programmed status are separate observations.

The EBCM table describes mismatch between stored and actual identification after an ECU exchange, missing calibration data, and invalid wheel-speed-sensor type configuration or nonvolatile-memory access failure. These rows do not mean an engine-controller reflash is the universal answer to P0602.

Make the next decision module specific

Determine the reporting module and any recent replacement or configuration work. Those facts select which programming-status test is relevant. A code in a brake controller requires the correct brake-system service process, including its prescribed verification; the source is not a procedure for manually changing calibration values.

After authorized setup is completed, confirm that the relevant startup or ongoing programming test passes and that the module identification/configuration matches the vehicle requirements. Do not transfer nearby valve-relay faults from the same PDF page into this code: those rows belong to a different monitor. The cited examples classify P0602 as Type A over one trip.

Source and applicability

Documented monitors in gm-2025-03a, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 18. GM 2025-03a, page 358.