DCM Data Signal Circuit between Navigation ECU and DCM: Procedure

1. Disconnect the L158 DCM (telematics transceiver) connector.
   Fig 1: Identifying L157 Display And L158 DCM Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the L157 display and navigation module display connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L158-1-1 (USB-) - L157-1-1 (DCM-)	Always	Below 1 Ω
   L158-1-2 (USB+) - L157-1-2 (DCM+)	Always	Below 1 Ω
   L158-1-3 (USBS) - L157-1-3 (DCMS)	Always	Below 1 Ω
   L158-2 (USBG) - L157-2 (UGND)	Always	Below 1 Ω
   L158-3 (VOT+) - L157-7 (VOR+)	Always	Below 1 Ω
   L158-4 (USBV) - L157-4 (USBV)	Always	Below 1 Ω
   L158-5 (VOT-) - L157-6 (VOR-)	Always	Below 1 Ω
   L158-6 (VOR-) - L157-5 (VOT-)	Always	Below 1 Ω
   L158-7 (VOR+) - L157-3 (VOT+)	Always	Below 1 Ω
   L158-1-1 (USB-) - Body ground	Always	10 kΩ or higher
   L158-1-2 (USB+) - Body ground	Always	10 kΩ or higher
   L158-1-3 (USBS) - Body ground	Always	10 kΩ or higher
   L158-2 (USBG) - Body ground	Always	10 kΩ or higher
   L158-3 (VOT+) - Body ground	Always	10 kΩ or higher
   L158-4 (USBV) - Body ground	Always	10 kΩ or higher
   L158-5 (VOT-) - Body ground	Always	10 kΩ or higher
   L158-6 (VOR-) - Body ground	Always	10 kΩ or higher
   L158-7 (VOR+) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to DCM [Telematics Transceiver])
   *b	Front view of wire harness connector (to Display and Navigation Module Display)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   2