P05D5

Symptoms

• Check Engine Light Is On
• No response when trying to change driving mode
• Constant operation in default mode
• Changed response to the gas pedal
• Possible malfunctions of the adaptive suspension

Causes

• Switch B signal wire short to ground
• Poor contact or corrosion in switch connector
• Switch B reference voltage open circuit
• Mechanical damage to the wiring harness
• Internal short in the switch itself

How to Fix

1. Connect the scanner and read all active and saved codes
2. Inspect switch connector B: check for corrosion, broken pins, traces of moisture
3. Measure the voltage on the signal wire of the switch with the ignition on - expect a value above 0.2–0.5 V depending on the model
4. Test the signal wire from the switch connector to the ECU for a short to ground.
5. Check the switch separately with an ohmmeter or oscilloscope
6. Repair wiring damage or replace mode switch B

Related codes

Error P05D5 by Vehicle Brand