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U0218 Lost Communication With Door Switch D

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U0218 means door switch unit D has gone silent. Rear-door panels are often bus nodes in their own right; on the 2011 Saab 9-5, GM even gives the left and right rear door switch panels separate codes. A detail worth knowing is the window lockout: the driver's panel sends a child-lock bit in its LIN reply, and according to NXP AN2205 the BCM or the individual window modules evaluate this bit and block the rear keys. When a rear panel stops answering, its window can often still be run from the driver's side; if the driver's panel is the one missing, the lockout status may be gone as well. No manufacturer documents U0218 publicly; letter D is assigned per make. No MIL.

Likely causes

Broken wire in the harness passage to the door
Moisture or corrosion at the switch panel connector
Switch panel D failed
Body or door module not polling the panel correctly

Symptoms

  • Window key in one door has no effect
  • Same window still moves from the driver's panel
  • Rear window lockout behaves unexpectedly

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–350
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

door switch dlin bus

Related codes

U0215U0216U0217U0219U0220U0221U0519U0203U0204

References: nxp.com, en.wikipedia.org, saabwisonline.com.