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 or F-CAN loss of communication errors first, then do this diagnosis if the HDS is not available.

1. Check the No. A15 (10 A) fuse in the under-hood fuse/relay box and the No. B5 (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 fuses. If the fuse blows again, repair the short to ground on a fuse circuit(s).

2. Remove the driver's dashboard lower cover.

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

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





5. Wait 5 seconds, and watch the front individual map lights, and ceiling light and ignition key 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 gauge control module odo/trip display while still in Test Mode 1. Press the SEL/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.

NOTE: If the test times out, remove the MPCS service connector, turn the ignition switch to LOCK (0), and repeat steps 3 and 4.

Are any DTCs indicated?

YES -

Go to step 7.

NO -

Go to step 11.

7. Record all DTCs and sort them by DTC type.

8. Troubleshoot the DTC(s) in this order:

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

9. Clear the DTCs by pressing and holding the SEL/RESET button for at least 10 seconds.

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

Test Mode 2

11. Remove the MPCS service connector from the driver's under-dash fuse/relay box multiplex control inspection connector socket for 5-10 seconds, then re-insert it to enter Mode 2. When the system enters Mode 2, the front individual map lights, ceiling light, and ignition key light flash two times quickly and then go 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.

12. 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 front individual map lights, ceiling light, and ignition key light blinks once. If the circuit is faulty, there is 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.