Toyota Avalon (XX50): How To Proceed With Troubleshooting. Illumination Circuit. Illumination for Panel Switch does not Come on with Tail Switch ON

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

HINT:

• Use the following procedure to troubleshoot the audio and visual system.
• *: Use the Techstream.

PROCEDURE

NEXT

• When troubleshooting, check that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
• Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.
• The following 5 items are important points for problem analysis:

  What	Vehicle model, system name
  When	Date, time, occurrence frequency
  Where	Road conditions
  Under what conditions?	Driving conditions, weather conditions
  How did it happen?	Problem symptoms

NEXT

(a) Measure the auxiliary battery voltage with the power switch off.

Standard Voltage:

11 to 14 V

HINT:

If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step.

NEXT

(a) Check that condensation is not likely to occur in the cabin and that the temperature is not high or extremely low in the cabin.

OK:

Condensation is not likely being produced and the temperature is not high or extremely low.

HINT:

• A humid cabin and a rapid change in temperature may lead to condensation. Condensation in the cabin may cause a short circuit.
• The audio and visual system may not operate normally when the temperature is -20°C (-4°F) or lower, or 65°C (149°F) or higher.

NG

SET CABIN TO APPROPRIATE TEMPERATURE

OK

(a) Check if CAN communication system DTCs are output.

Click here

B

GO TO CAN COMMUNICATION SYSTEM

A

(a) Check for DTCs.

B

GO TO STEP 10

A

(a) Clear the DTCs.

HINT:

The present DTCs may not indicate actual malfunctions depending on the vehicle operating conditions.

NEXT

(a) Recheck for DTCs.

HINT:

• Even if the problem symptom is not confirmed, check for DTCs. This is because the system stores history DTCs.
• If more information is needed, perform a recheck using the "System Check Mode" screen after rechecking for DTCs using the Techstream.
• Check for DTCs and inspect the area that the code indicates.

B

GO TO STEP 10

A

(a) Find the output DTC in Diagnostic Trouble Code Chart.

Click here

NEXT

GO TO STEP 12

(a) Refer to Problem Symptoms Table.

Click here

HINT:

If the symptoms do not recur and no DTCs are output, attempt to reproduce the symptoms.

Click here

B

GO TO STEP 12

A

(a) Refer to Terminals of ECU.

Click here

NEXT

(a) Adjust, repair or replace as necessary.

NEXT

(a) After clearing DTCs, recheck for DTCs.

NEXT

NEXT

END

Illumination Circuit

DESCRIPTION

Power is supplied to the radio and display receiver assembly and steering pad switch assembly illumination when the light control switch is in the tail or head position.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• The vehicle is equipped with a Supplemental Restraint System (SRS) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the precaution for Supplemental Restraint System.

  Click here

• Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

(a) Check if the illumination for the radio and display receiver assembly, steering pad switch assembly, heater control switch or others (hazard switch, transmission control switch, etc.) comes on when the light control switch is turned to the head or tail position.

B

GO TO STEP 5

C

GO TO LIGHTING SYSTEM

A

(a) Disconnect the G17 spiral cable sub-assembly connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Remove the steering pad switch assembly.

Click here

(b) Inspect the steering pad switch assembly.

Click here

NG

REPLACE STEERING PAD SWITCH ASSEMBLY

OK

(a) Remove the spiral cable sub-assembly.

Click here

(b) Inspect the spiral cable sub-assembly.

Click here

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - RADIO AND DISPLAY RECEIVER ASSEMBLY, COMBINATION METER ASSEMBLY)

NG

REPLACE SPIRAL CABLE SUB-ASSEMBLY

(a) Disconnect the G2 radio and display receiver assembly connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Disconnect the G2 radio and display receiver assembly connector.

(b) Disconnect the G16 combination meter assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Illumination for Panel Switch does not Come on with Tail Switch ON

CAUTION / NOTICE / HINT

NOTICE:

• Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Audio and Visual System.

  Click here

• When replacing the radio and display receiver assembly, always replace it with a new one. If a radio and display receiver assembly which was installed to another vehicle is used, the following may occur:
  • A communication malfunction DTC may be stored.
  • The radio and display receiver assembly may not operate normally.

PROCEDURE

(a) Enter the "Vehicle Signal Check Mode" screen. Refer to Check Vehicle Signal in Operation Check. Click here

(b) Check that the display changes between ON and OFF according to the light control switch operation.

OK:

HINT:

• This display is updated once per second. As a result, it is normal for the display to lag behind the actual switch operation.
• Make sure to move the vehicle to a bright area before performing an operation check with the light control switch in the AUTO position.

OK

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

NG

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE