Inspection Procedure
1: Power of the radio and tape player does not turn ON when the ignition switch is in the "ACC"
position or "ON" position. <Vehicles with Auto Stop & Go (AS&G) System>
caution
Before replacing the radio
and CD player, ensure that the power supply circuit, the earth circuit and the communication
circuit are normal.
OPERATION
When the ignition switch is in the ON or ACC position, the radio and CD player power can
be turned ON. With the radio and CD player power ON, when the ignition switch is turned to the
OFF position, the power for radio and CD player is also turned OFF.
COMMENTS ON TROUBLE SYMPTOM
Provided that the audio diagnosis code is not set, if the power for radio and CD player
cannot be turned ON, the radio and CD player, or power supply circuit for radio and CD player
may have a problem, or the option coding information may be inconsistent.
PROBABLE CAUSES
Malfunction of radio and CD player
Malfunction of the ETACS-ECU
Malfunction of the DC/DC converter
Option coding information inconsistency
Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
STEP 1. ETACS-ECU coding data check
(1)Operate the M.U.T.-III to read the ETACS-ECU option coding information (Refer to
GROUP 00 - Coding Table ).
(2)Check that the "AUDIO" is set to "Present."
Q.
Is the check result normal?
Go to Step 2.
Operate the M.U.T.-III to set the option coding "AUDIO" to "Present," and check
the trouble symptom.
STEP 2. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 3.
Repair the CAN bus line.
STEP 3. M.U.T.-III other system diagnosis code
Check if the diagnosis code is set to the ETACS-ECU.
Q.
Is the check result normal?
Troubleshoot the ETACS-ECU. Refer to ETACS-ECU - Troubleshooting .
Go to Step 4.
STEP 4. M.U.T.-III other system data list
Check the input signal of ACC relay.
Turn the ignition switch to the ACC position.
Item No.
Item name
Normal condition
Item 288
ACC switch
ON
OK: Normal condition is displayed.
Q.
Is the check result normal?
Go to Step 5.
Refer to ETACS - Inspection Procedure 1 "The ignition switch (ACC) signal
is not received" .
STEP 5. Check the DC/DC converter.
Check the continuity of the DC/DC converter.
Q.
Is the check result normal?
Go to Step 6
Replace the DC/DC converter.
STEP 6. Voltage measurement at DC/DC converter connector
(IGN terminal).
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the ACC position.
(3)Check the voltage between DC/DC converter connector (IGN terminal) and
body earth. OK: System voltage
Q.
Is the check result normal?
Go to Step 8
Go to Step 7
STEP 7. Check of short to power supply, short to earth, and open circuit
in IGN line between DC/DC converter connector and ETACS-ECU connector
Q.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to use Troubleshooting/inspection Service Points - How to Cope with Intermittent
Malfunction ).
Repair the connector(s) or wiring harness.
STEP 8. Voltage measurement at DC/DC converter connector
(PWR terminal).
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Check the voltage between DC/DC converter connector (PWR terminal) and
body earth. OK: System voltage
Q.
Is the check result normal?
Go to Step 10
Go to Step 9
STEP 9. Check of short to power supply, short to earth, and open circuit
in PWR line between fusible link and DC/DC converter connector
Q.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to use Troubleshooting/inspection Service Points - How to Cope with Intermittent
Malfunction ).
Repair the connector(s) or wiring harness.
STEP 10. Check the wiring harness between the DC/DC converter
connector terminal and the radio and CD player connector terminal.
Check of short to power supply, short to earth, and open circuit in OUT1
line between DC/DC converter connector and radio and CD player connector.
Check of short to power supply, short to earth, and open circuit in OUT2 line between
DC/DC converter connector and radio and CD player connector.
Q.
Is the check result normal?
Go to Step 11
Repair the connector(s) or wiring harness.
STEP 11. Check of open circuit in GND2 line between radio and CD player
connector and body earth
Q.
Is the check result normal?
Go to Step 12.
Repair the connector(s) or wiring harness.
STEP 12. Check that the radio and CD player is correctly earthed
The radio and CD player should be connected to the earth with an assembling screw.
Q.
Is the radio and CD player correctly earthed?
Go to Step 13.
Securely install and earth the radio and CD player.
STEP 13. Retest the system
Check if the radio and CD player power is turned ON.
Q.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to use Troubleshooting/inspection Service Points - How to Cope with Intermittent
Malfunction ).
).
Go to Step 2.
Operate the M.U.T.-III to set the option coding "AUDIO" to "Present," and check
the trouble symptom.