Troubleshooting - B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS)

Multiplex Integrated Control System Troubleshooting - B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS)

Special Tools Required

- MPCS (MCIC) Service Connector 07WAZ-001010A

Test Mode 1

Check the PCM for DTCs and troubleshoot PCM Initial Inspection and Diagnostic Overview or F-CAN loss of communication errors first, then do this diagnosis if the HDS is not available.

1. Check the No. 15 (10 A) fuse in the under-hood fuse/relay box and No. 5 (7.5 A) fuse in the driver's under-dash fuse/relay box.

Are the fuses OK?

YES -

Go to step 2.

NO -

Replace the fuse. If the fuse blows again, repair the short to ground on the fuse circuit.�

2. Remove the driver's dashboard lower cover Driver's Dashboard Lower Cover Removal/Installation.

3. Turn the ignition switch to ON (II), and move the ceiling light switch to the middle (door) position.

4. Connect the MPCS service connector (A) to the MICU service check connector socket (B) in the driver's under-dash fuse/relay box.





5. Wait 5 seconds, and watch the ceiling light. When the ceiling light flashes quickly once and then goes off, the system is in Test Mode 1.

6. Check for B-CAN DTCs indicated by the multi-information display (MID) on the gauge control module while still in Test Mode 1. Push the odometer SELECT/RESET button to display the next code. After you get to the last code, the display shows END. If no DTCs are stored, the display will read NO.

Are any DTCs indicated?

YES -

Go to step 7.

NO -

Go to step 9.

7. Record all DTCs and troubleshoot them in this order:

- Battery voltage DTCs
- Internal error DTCs
- Loss of communication DTCs
- Signal error DTCs

8. Clear the DTCs by pressing and holding the SEL/RESET button for about 10 seconds.

9. You will hear a beep to confirm the codes have been cleared. Operate the devices that failed, and recheck for codes.

Test Mode 2

10. Remove the MPCS service connector from the driver's under-dash fuse/relay box MICU service check connector socket for 5-10 seconds, then re-insert it to enter Mode 2. When the system enters Mode 2, the ceiling light flashes two times quickly and then goes off.

NOTE: If the MPCS service connector is disconnected for too short or too long of a time, or the ignition switch is turned to LOCK (0), the system returns to Test Mode 1.

11. The following tables list the circuits that can be checked in Test Mode 2. Operate the switch that is most closely related to the problem. If the circuit is OK, the ceiling light will blink once. If the circuit is faulty, there will be no indication.

Driver's MICU





Passenger's MICU





Door Multiplex Control Unit










Front Passenger's Power Window Switch





Power Seat Control Unit





Does the ceiling light work properly in all switch positions?

YES -

Go to function and input test for the system related to the failure.�

NO -

Repair the open, short, or replace the faulty switch.�