DTC Troubleshooting: U0199
DTC U0199:
 Driver's MICU Lost Communication with Door Multiplex Control Unit
  1. Clear the DTCs with the HDS.
  1. Turn the ignition switch to LOCK (0) and then back to ON (II).
  1. Wait for 6 seconds or more.
  1. Check for DTCs with the HDS.
Is DTC U0199 indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure, the system is OK at this time. Check for loose or poor connections.■
  1. Check for DTCs with the HDS.
Is DTC U1280 indicated?
YES -
Go to the DTC U1280 troubleshooting.■
NO -
Go to Step 6 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the door multiplex control unit 37P connector.
  1. Disconnect driver's under-dash fuse/relay box connector P (20P).
  1. Check for continuity between door multiplex control unit 37P connector No. 33 and No. 35 terminals and driver's under-dash fuse/relay box connector P (20P) No. 5 and No. 6 terminals individually.
Is there continuity?
YES -
Go to the power window master switch input test, and do all power and ground input tests. If the tests prove OK, replace the power window master switch.■
NO -
An open in the wire.■