P0592 Cruise Control Multi-Function Input B Circuit Low

P0592 points to a low condition in Cruise Control Multi-Function Input B circuit. The input B signal is below the expected voltage or data range.

Code details

Generic OBD-II · P0

System: Speed / Idle
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace multiple switches before testing the input B circuit and clockspring path.

Symptoms of P0592

Unstable, high, or low idle, or stalling.
Erratic speedometer, cruise-control, or shift behaviour.
Check-engine light with a hesitation or surge.

Common causes of P0592

A dirty throttle body, idle-control valve, or throttle-position sensor.
A failing vehicle-speed or wheel-speed sensor, or its wiring.
Vacuum leaks or a related sensor forcing the idle/speed strategy.

Useful checks before replacing parts

Check input B voltage, switch-state data, shared reference voltage, ground, input A correlation, brake status, and freeze-frame conditions.
Inspect for short-to-ground faults, open reference circuits, damaged clockspring wiring, switch contamination, and connector corrosion.
Measure input B through each switch position to identify whether one command or the shared circuit is pulling the value low.

Related OBD-II codes

These nearby speed / idle entries can help compare wording and pin down the fault area.