Cruise Control Decrease Distance Signal Malfunction
The P056B code indicates that the powertrain control module (PCM) has detected a fault in the cruise control decrease distance signal circuit. This signal is typically sent by the steering wheel-mounted cruise control switch or a distance sensor to request a reduction in the following distance in adaptive cruise control systems. The issue may be due to a faulty switch, wiring problems, or a malfunctioning sensor.
01. Most Common Causes
- Faulty cruise control decrease distance switch
- Damaged or corroded wiring/connectors in the cruise control circuit
- Malfunctioning adaptive cruise control sensor or module
02. Symptoms You Will Notice
- Cruise control inoperative or intermittent
- Inability to decrease following distance in adaptive cruise control
- Check engine light or cruise control warning light illuminated
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the cruise control switch and wiring for damage or corrosion.
Step 3: Test the switch continuity with a multimeter; replace if faulty.
Step 4: Check the adaptive cruise control sensor alignment and connections.
Step 5: Clear the code and test drive to verify repair.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but cruise control may not work properly. If the adaptive cruise control fails, you can still drive manually.
How much does it cost to fix?▼
Typically $50-$150 for switch replacement or wiring repair, but sensor replacement can cost more.