Inspection Procedure 5

The Multi-Center Display does not Display the Information Concerning the Audio System Correctly.

Multi-center Display Communication Circuit:

CIRCUIT OPERATION
The multi-center display and the radio, tape player, CD player and CD auto changer communicate with each other. The multi-center display shows the information concerning the radio, tape player, CD player and CD auto changer on the screen, based on that communication.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably a faulty multi-center display communication circuit.

TROUBLESHOOTING HINTS
- Damaged wiring harness or connector.
- Malfunction of the multi-center display.
- Malfunction of the radio, tape player, CD player and CD auto changer.

DIAGNOSIS

Required Special Tool:
- MB991223: Harness set

STEP 1. Check the time display function of the multi-center display.

Q: Dose the time display function of the multi-center display operate normally?

YES: Go to Step 5.

NO: Go to Step 2.




STEP 2. Check multi-center display connector C-09 and radio, tape player, CD player and CD auto changer connector C-21 for damage.

Q: Are multi-center display connector C-09 and radio, tape player, CD player and CD auto changer connector C-21 in good condition?

YES: Go to Step 3.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. The multi-center display should display the information concerning the audio system correctly.




STEP 3. Check the wiring harness between multi-center display connector C-09 (terminals 7, 8, 9, 10) and radio, tape player, CD player and CD auto changer connector C-21 (terminals 21, 22, 25, 26).

Q: Are the wiring harness between multi-center display connector C-09 (terminals 7, 8, 9, 10) and radio, tape player, CD player and CD auto changer connector C-21 (terminals 21, 22, 25, 26) in good condition?

YES: Go to Step 4.

NO: Repair the wiring harness. The multi-center display should display the information concerning the audio system correctly.

STEP 4. Replace the radio.

1. Replace the radio.
2. The system should communicate with the multi-center display normally.

Q: Does the multi-center display show information concerning audio system correctly?

YES: No action to be taken.

NO: Replace the radio, tape player, CD player and CD auto changer.

STEP 5. Check the multi-center display power supply circuit (battery) at the multi-center display connector C-09 by backprobing.




1. Do not disconnect the multi-center display connector C-09 and measure at the harness side.




2. Measure the voltage between terminal 1 and ground by backprobing.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES: Go to Step 8.

NO: Go to Step 6.




STEP 6. Check multi-center display connector C-09 for damage.

Q: Is multi-center display connector C-09 in good condition?

YES: Go to Step 7.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. The multi-center display should display the information concerning the audio system correctly.







STEP 7. Check the wiring harness between C-09 and battery.

NOTE: After checking joint connector C-78 and intermediate connector C-89, check the wires. If joint connector C-78 and intermediate connector C-89 are damaged, repair or replace them. Refer to Harness Connector Inspection.

Q: Is the wiring harness between C-09 and battery in good condition?

YES: There is no action to be taken.

NO: Repair the wiring harness. The multi-center display should display the information concerning the audio system correctly.

STEP 8. Check the multi-center display power supply circuit (ACC) at the multi-center display connector C-09 by backprobing.




1. Do not disconnect the multi-center display connector C-09 and measure at the harness side.
2. Turn the ignition switch to the "ACC" position.




3. Measure the voltage between terminal 3 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES: Go to Step 11.

NO: Go to Step 9.




STEP 9. Check multi-center display connector C-09 for damage.

Q: Is multi-center display connector C-09 in good condition?

YES: Go to Step 10.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. The multi-center display should display the information concerning the audio system correctly.










STEP 10. Check the wiring harness between multi-center display connector C-09 (terminal 3) and the ignition switch (ACC).

NOTE: After checking joint connector C-78 and junction block connector C-108 and C-111, check the wires. If joint connector C-78 and junction block connector C-108 and C-111 are damaged, repair or replace them. Refer to Harness Connector Inspection.

Q: Is the wiring harness between multi-center display connector C-09 (terminal 3) and the ignition switch (ACC) in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. The multi-center display should display the information concerning the audio system correctly.

STEP 11. Check the multi-center display power supply circuit (IG1) at the multi-center display connector C-09 by backprobing.




1. Do not disconnect the multi-center display connector C-09 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.




3. Measure the voltage between terminal 2 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Does the measured voltage correspond with this range

YES: Go to Step 14.

NO: Go to Step 12.




STEP 12. Check multi-center display connector C-09.

Q: Is multi-center display connector C-09 in good condition?

YES: Go to Step 13.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. The multi-center display should display the information concerning the audio system correctly.










STEP 13. Check the wiring harness between multi-center display connector C-09 (terminal 2) and the ignition switch (IG1).

NOTE: After checking joint connector C-78 and junction block connector C-111 and C-112, check the wires. If joint connector C-78 and junction block connector C-111 and C-112 are damaged, repair or replace them. Refer to Harness Connector Inspection.

Q: Is the wiring harness between multi-center display connector C-09 (terminal 2) and ignition switch (IG1) in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. The multi-center display should display the information concerning the audio system correctly.

STEP 14. Check the multi-center display ground circuit at the multi-center display connector C-09 by backprobing.




1. Do not disconnect the multi-center display connector C-09 and measure at the harness side.




2. Measure the resistance between terminal 6 and ground by backprobing.
- The measured value should be 2 ohm or less.

Q: Does the measured resistance value correspond with this range?

YES: Replace the multi-center display.

NO: Go to Step 15.




STEP 15. Check the multi-center display connector C-09 for damage.

Q: Is the multi-center display connector C-09 in good condition?

YES: Go to Step 16.

NO: Repair or replace the connector. Refer to Harness Connector Inspection.The multi-center display should display the information concerning the audio system correctly.







STEP 16. Check the wiring harness between multi-center display connector C-09 and ground.

NOTE: After checking joint connector C-78, check the wires. If joint connector C-78 is damaged, repair or replace it. Refer to Harness Connector Inspection.

Q: Is the wiring harness between multi-center display connector C-09 and ground in good condition?

YES: There is no action to be taken.

NO: Repair the wiring harness. The multi-center display should display the information concerning the audio system correctly.