P0592: cruise switch B input in the short-to-ground range

P0592 monitors cruise-control multifunction switch circuit B for a low analog input. In the cited strategy, an analog-to-digital count ratio from 0 to 0.185 is classified as the short-to-ground range.

A ratio is not a terminal voltage

The published limit belongs to the controller's normalized input interpretation. It should not be applied as a 0.185 V specification at a connector. Identifying the actual input scaling through service information is necessary before choosing a meter test.

The condition must last two seconds within a 25-second sample period. With the cruise-switch diagnostic enabled, the BCM reports the low input to the ECM. The ECM then disables and disengages cruise control for the remainder of the key cycle, even if the input subsequently becomes valid.

Useful verification evidence

Preserve the input ratio and its duration, not merely the fact that cruise is unavailable. A latched disable after recovery and a presently low signal are different observations and can lead to different service conclusions.

The table lists Type B, two-trip reporting. Verification should establish recognized switch-input states without the low-range fault using the applicable service procedure. This monitor does not locate a ground short or prove that replacing the steering-wheel switch will resolve it. Electrical testing around driver controls must follow the vehicle-specific access and circuit instructions.

Source and applicability

2025 GM 25OBDG04B diagnostic parameter tables; the cited monitor only. Vehicle, engine and calibration applicability must be confirmed separately. These tables describe detection logic, not a complete repair procedure or a component replacement verdict. gm-2025-04b, PDF page 567.