Inspection Procedure 1

INSPECTION PROCEDURE 1: The multi-center display does not Show any Information.


















CIRCUIT OPERATION

The multi-center display unit is energized by the battery through the ignition switch (ACC) and (IG1).

TECHNICAL DESCRIPTION (COMMENT)

The ground circuit, the battery circuit, the ignition switch (ACC) circuit or the ignition switch (IG1) circuit is suspected to be open or defective.

TROUBLESHOOTING HINTS

- Malfunction of the multi-center display unit
- Damaged wiring harness and connectors

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check the multi-center display unit connector C-06 for loose, corroded or damaged terminals, or terminals pushed back in the connector.





Q. Is the multi-center display unit connector C-06 in good condition?

YES Go to Step 2.

NO Repair or replace the connector. Harness Connector Inspection.

STEP 2. Check the multi-center display unit ground circuit. Measure the resistance at the multi-center display unit connector C-06.





(1)Disconnect the multi-center display unit connector C-06 and measure at the harness side.





(2)Measure the resistance between terminal 6 and ground.

- The measured value should be 2 ohm or less.

Q. Is the measured resistance 2 ohm or less?

YES Go to Step 4.

NO Go to Step 3.

STEP 3. Check the wiring harness between multi-center display unit connector C-06 (terminal 6) and ground.









NOTE:
After checking joint connector (2) C-01 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. check the wires. If joint connector (2) C-01 is damaged, repair or replace the wiring harness. Harness Connector Inspection.

Q. Is the wiring harness between multi-center display unit connector C-06 (terminal 6) and ground in good condition?

YES There is no action to be taken.

NO Repair the wiring harness. The multi-center display unit should work normally.

STEP 4. Check the multi-center display unit power supply circuit (battery). Measure the voltage at the multi-center display unit connector C-06.





(1)Disconnect the multi-center display unit connector C-06 and measure at the harness side.





(2)Measure the voltage between terminal 1 and ground.

- The measured value should be approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts?

YES Go to Step 6.

NO Go to Step 5.

STEP 5. Check the wiring harness between multi-center display unit connector C-06 (terminal 1) and battery.









NOTE:
Also check intermediate connector C-24 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-24 is damaged, repair or replace the wiring harness. Harness Connector Inspection.

Q. Is the wiring harness between multi-center display unit connector C-06 and battery in good condition?

YES There is no action to be taken.

NO Repair the wiring harness. The multi-center display unit should work normally.

STEP 6. Check the multi-center display unit power supply circuit [ignition switch (ACC)]. Measure the voltage at the multi-center display unit connector C-06.





(1)Disconnect the multi-center display unit connector C-06 and measure at the harness side.
(2)Turn the ignition switch to "ACC" position.





(3)Measure the voltage between terminal 3 and ground by backprobing.

- The measured value should be approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts?

YES Go to Step 8.

NO Go to Step 7.

STEP 7. Check the wiring harness between multi-center display unit connector C-06 (terminal 3) and ignition switch (ACC).









NOTE:
Also check joint connector (2) C-01, and intermediate connector C-24 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If or joint connector (2) C-01 or intermediate connector C-24 is damaged, repair or replace the wiring harness. Harness Connector Inspection.

Q. Is the wiring harness between multi-center display unit connector C-06 (terminal 3) and ignition switch (ACC) in good condition?

YES Refer to ignition switch diagnosis Malfunction of the Ignition Switch Power Supply System.

NO Repair the wiring harness. The multi-center display unit should work normally.

STEP 8. Check the multi-center display unit power supply circuit [ignition switch (IG1)]. Measure the voltage at the multi-center display unit connector C-06.





(1)Disconnect the multi-center display unit connector C-06 and measure at the harness side.
(2)Turn the ignition switch to "ON" position.





(3)Measure the voltage between terminal 2 and ground.

- The measured value should be approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts?

YES Replace the multi-center display unit. The multi-center display unit should work normally.

NO Go to Step 9.

STEP 9. Check the wiring harness between multi-center display unit connector C-06 (terminal 2) and ignition switch (IG1).













NOTE:
Also check joint connector (2) C-01, junction block connectors C-202 and C-215 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector (2) C-01 or junction block connectors C-202 or C-215 is damaged, repair or replace the wiring harness. Harness Connector Inspection.

Q. Is the wiring harness between multi-center display unit connector C-06 (terminal 2) and ignition switch (IG1) in good condition?

YES Refer to ignition switch diagnosis Malfunction of the Ignition Switch Power Supply System.

NO Repair the wiring harness. The multi-center display unit should work normally.