U0216
Lost Communication With Door Switch B
Network communication
Generic OBD-II
Low
What it means
U0216 sets when a module can no longer reach Door Switch B over the data bus — the switch pack on that door that sends window, lock, and mirror commands to the network. Nothing in the powertrain is affected, so the vehicle drives normally; only that door's switch functions go down.
Low
Can I keep driving? Yes — the window, lock, and mirror switches on that door stops working, but the engine, brakes, and steering are unaffected, so you can keep driving until it's convenient to repair.
Common symptoms
What you'll notice
- Window, lock, or mirror switches on that door stop responding
- Driver's master switch may not control the other windows
- One-touch/express window function lost
- Feature works intermittently as the door harness flexes
Common causes
Most likely first
- Corroded, loose, or damaged connector at the module or an inline body connectorLikely
- Chafed, broken, or shorted wiring in the communication (CAN) circuit to the moduleCommon
- Loss of switched power or ground to the affected moduleCommon
- Water intrusion into a body/door connector or the module itselfLess often
- Failed module with an internal faultLess often
- A wider data-bus problem pulling the network downLess often
How to diagnose & fix
Work through it in order
- Scan every module and note all U-codes first — several codes together point to a bus or gateway fault rather than one module.
- Inspect the connector and harness at the module for corrosion, bent pins, water, or chafing (door harnesses flex every time the door opens and are a common break point).
- Confirm the module has good switched power and a clean ground with a multimeter.
- Check communication-bus continuity and resistance from the module back to the network.
- If wiring and power are good, the module is likely faulty — replace and program/configure it as required.
- Clear the code, recheck, and confirm the affected feature works and the code stays gone.
FAQ
Quick answers
Is it safe to drive with U0216?+
Yes. U0216 affects only the window, lock, and mirror switches on that door; it has no effect on the engine, brakes, or steering, so the car starts and drives normally. Repair it to restore the feature.
Can I just clear U0216?+
You can clear it, but if the module is still off the bus the code returns almost immediately. Fix the wiring, connector, power/ground, or module first, then clear and confirm the feature works.
Related codes
Often seen with U0216
Read & clear U0216 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX