Radio Receiver Communication Error

1. Enter the diagnostic mode.
   Fig 1: Entering Diagnostic Mode (Example)

   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 Fig 1 .
• For details of the DTC display, refer to "DTC CHECK / CLEAR " .

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: 

   POWER SOURCE CIRCUIT OF COMPONENT SHOWN BY SUB-CODE
   
   

   Component	Proceed to
   Stereo component amplifier (440)	Stereo component amplifier power source circuit (See STEREO COMPONENT AMPLIFIER POWER SOURCE CIRCUIT  )
   Television display assembly (1B0)	Television display assembly power source circuit (See TELEVISION DISPLAY POWER SOURCE CIRCUIT )

1. Disconnect the radio receiver connectors.
2. Measure the resistance according to the value(s) in RADIO RECEIVER  .

   Standard resistance 

   RADIO RECEIVER
   
   

   Tester Connection	Condition	Specified Condition
   ATX+ (R7-5) - ATX- (R7-15) ((1))	Always	60 to 80 Ω
   TXM+ (R8-9) - TXM- (R8-10)	Always	60 to 80 Ω
   (1) 10 Speaker System

   Fig 2: Inspecting Radio Receiver

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE RADIO RECEIVER 

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 the "TERMINALS OF ECU " .

1. Referring to the AVC-LAN wiring diagram in Fig 3 , check the AVC-LAN circuit between the radio receiver and the component shown by the sub-code.
   1. Disconnect all connectors between the radio receiver and the component shown by sub-code.
   2. Check for an open or short in the AVC-LAN circuit between the radio receiver 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 

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 RADIO RECEIVER 

OK: END