Navigation ECU Communication Error: Procedure

1. Enter the diagnostic mode.
   Fig 1: Diagnosis Display Screen - Lam Monitor Mode

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Press the "LAN Mon" switch to change to "LAN Monitor" mode.
3. Identify the component shown by the sub-code.

   HINT: 

   • "110 (multi-display)" is the component shown by the sub-code in the example shown in the illustration.
   • The sub-code will be indicated by its physical address.
   • For the component list, refer to Diagnosis Display Detailed Description in the System Description. Refer to SYSTEM DESCRIPTION .

NEXT: Go to next step 

1. Inspect the power source circuit of the component shown by the sub-code.

   If the power source circuit is operating normally, proceed to the next step.

   COMPONENT TABLE
   
   

   Component	Proceed to
   Radio receiver (190)	Radio receiver power source circuit. Refer to Radio Receiver Power Source Circuit
   Stereo component amplifier (440)	Stereo component amplifier power source circuit. Refer to Stereo Component Amplifier Power Source Circuit
   Multi-display (110)	Multi-display power source circuit. Refer to Multi-display Power Source Circuit
   Gateway ECU (1C6)	Gateway ECU power source circuit. Refer to Gateway ECU Power Source Circuit

NEXT: Go to next step 

1. Disconnect the radio receiver connectors.
   Fig 2: Identifying Connector Terminals Of Radio Receiver

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   J66-5 (ATX+) - J66-15 (ATX-)	Always	60 to 80 Ω
   J63-9 (TX+) - J63-10 (TX-)	Always	60 to 80 Ω

NG → See step   6 

OK: Go to next step 

HINT: 

• Start the check from the circuit that is near the component shown by the sub-code first.
• For details of the connectors, refer to Terminals of ECU. Refer to TERMINALS OF ECU .

1. Referring to AVC-LAN Wiring Diagram below, check the AVC-LAN circuit between the navigation ECU and the component shown by the sub-code.
   1. Disconnect all connectors between the navigation ECU and the component shown by sub-code.
   2. Check for an open or short in the AVC-LAN circuit between the navigation ECU and the component shown by the sub-code.

      OK

      There are no open or short circuits.

      Fig 3: AVC-LAN -- Wiring Diagram

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the component shown by the sub-code with a known good one and check if the same problem occurs again.

   OK

   Same problem does not occur.

NG → See step   7 

OK → END