U0216: Lost Communication With Door Switch B

What it means

The reporting module has lost communication with door switch B. It sets this code when expected switch messages are not received for a specified time.

How it works

Door Switch B reports door status to other modules over the vehicle network. This code is set when the reporting module misses expected messages from switch B for the required period; it does not identify the door location by itself.

Common causes

Most likely first.

1. Switch power or ground fault
2. Damaged or corroded wiring or connectors
3. CAN bus fault
4. Door switch B failure
5. Low battery voltage

Symptoms

• Door status may display incorrectly
• Door warning or courtesy light may malfunction
• Other communication codes

How to diagnose it

1. Record freeze-frame data and scan for other communication codes to see whether the fault is limited to Door Switch B.
2. Check battery condition and inspect the power and ground connections supplying switch B.
3. Inspect the switch B connector and its wiring for corrosion, loose terminals, physical damage, or a broken conductor.
4. Use a scan tool to compare switch B's reported door status with the actual door position and check module response.
5. If supply wiring is sound, test the relevant network path and switch operation against the manufacturer's specification.

Common fixes

• Secure or clean the power, ground, or connector connection at Door Switch B.
• Repair damaged wiring or corroded terminals to switch B.
• Resolve a low battery or charging fault if it caused the messages to drop out.
• Repair a confirmed network wiring fault.
• Replace Door Switch B if it fails testing with sound power, ground, and network connections.

Can I keep driving?

The vehicle is generally drivable, but the status warning or courtesy light associated with switch B may be incorrect. Check that each door is firmly latched before setting off and do not rely on the display alone.