P05BD
Stop Start Mode Switch Circuit Range/Performance
Generic OBD-II
Common symptoms
What you'll notice
- Check the wiring and connections of the Stop Start Mode Switch
- Replace the Stop Start Mode Switch
- Inspect and repair any damaged or corroded wires or connectors related to the Stop Start Mode Switch
- Reset the vehicle's computer system and perform a relearn procedure for the Stop Start Mode Switch
Common causes
Most likely first
- Faulty stop start mode switch
- Damaged or loose wiring/connectors related to the stop start mode switch
- Malfunctioning stop start mode relay
- Low battery voltage affecting the operation of the stop start mode system
- Faulty engine control module (ECM) or powertrain control module (PCM)
How to diagnose & fix
Work through it in order
- Engine may fail to start or may have difficulty starting
- Engine may suddenly shut off while driving
- Inability to switch between stop and start mode
- Poor fuel efficiency
- Engine may hesitate or stutter during acceleration
Read & clear P05BD yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.