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Multi-display Controller Communication Error

IDENTIFY THE COMPONENT SHOWN BY THE SUB-CODE
1. Enter the diagnostic mode.
  
  Fig 1: Multi-display Controller Communication Error Diagnostic Flow Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Press the preset switch "3" to change to "Detailed Information Mode".
3. Identify the component shown by the sub-code.
HINT:
- "190 (radio receiver)" is the component shown by the sub-code in the example shown in the illustration.
- For details of the DTC display, refer to the "DTC CHECK/ CLEAR " .

CHECK POWER SOURCE CIRCUIT OF COMPONENT SHOWN BY SUB-CODE

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 REFERENCE TABLE

Component	Proceed to
Stereo component amplifier (440)	STEREO COMPONENT AMPLIFIER POWER SOURCE CIRCUIT
Radio receiver (190)	RADIO RECEIVER POWER SOURCE CIRCUIT

INSPECT RADIO RECEIVER

Disconnect the radio receiver connector.
Measure the resistance according to the value(s) in the table below.

Resistance

RESISTANCE SPECIFIED CONDITION

Tester Connection	Condition	Specified Condition
ATX+(R2-5) - ATX-(R2-15)	Always	60 to 80 Ω
TX+(R3-9) - TX-(R3-10)	Always	60 to 80 Ω
TX+(R4-9) - TX-(R4-10)	Always	60 to 80 Ω

Fig 2: Identifying Radio Receiver Connector Terminals

G04092642

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE RADIO RECEIVER

OK: Go to next step

CHECK HARNESS AND CONNECTOR (MULTI-DISPLAY CONTROLLER - COMPONENT SHOWN BY SUB-CODE)
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 the "TERMINALS OF ECU " .
1. Referring to the AVC-LAN wiring diagram below, check the AVC-LAN circuit between the multi-display controller and the component shown by the sub-code.
  1. Check for an open or short in the AVC-LAN circuit between the multi-display controller and the component shown by the sub-code.
    OK: There is no open or short circuit.
Fig 3: AVC-LAN Wiring Diagram
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step
REPLACE COMPONENT SHOWN BY SUB-CODE
1. Replace the component shown by the sub-code with a normal one and check if the same problem occurs again.
  OK: Same problem does not occur.
NG: REPLACE MULTI-DISPLAY CONTROLLER

OK: END