Cruise Control Multi-Function Input Circuit Low
The P0592 code indicates that the powertrain control module (PCM) has detected a low voltage condition in the cruise control multi-function input circuit. This circuit carries signals from the cruise control switches (set, resume, cancel) to the PCM. A low voltage reading suggests a short to ground, a faulty switch, or a wiring issue, preventing the cruise control system from operating correctly.
1. Most Common Causes
- Faulty cruise control switch
- Short to ground in the multi-function input circuit
- Damaged wiring or connector
- Corroded terminals
- Faulty PCM (rare)
2. Symptoms You Will Notice
- Cruise control inoperative
- Cruise control light on dash may flash or stay on
- Engine Check Light illuminated
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P0592 and check for other codes.
Step 2: Visually inspect the cruise control switch and wiring for damage or corrosion.
Step 3: Test the switch resistance with a multimeter; compare to specs.
Step 4: Check for voltage at the switch connector; should be ~5V reference.
Step 5: If voltage is low, trace circuit for shorts to ground or open circuits.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive, but cruise control will not work. The vehicle's braking and steering remain unaffected.
How much does it cost to fix?▼
Repair costs typically range from $50 to $150 for switch replacement or wiring repair, but can be higher if the PCM needs replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.