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 perform this diagnosis if the HDS is not available.
1. Check the No. 7 (10 A) and No. 21 (10 A) fuses in the driver's under-dash fuse/relay box.
Are the fuses OK?
YES -
Go to step 2.
NO -
Find and repair the cause of the blown fuse.�
2. Remove the left kick panel Service and Repair, and the driver's dashboard under cover.
3. Turn the ignition switch to ON (II), and move the interior lights 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 map lights. When the system enters Mode 1, the front and rear map lights will flash quickly once, and a double beep will be heard.
6. If there is a DTC, the map lights and ignition key light will blink, pause, then repeat the DTC as long as the ignition switch is turned to ON (II).
Is there a repeating DTC?
YES -
Count the blinks, then go to step 7.
NO -
Go to step 8.
7. About 1 second after you go into self-diagnostic Mode 1, the map lights will indicate the DTC, and repeat it every 3 seconds. If there is more than one DTC, the system will indicate them in ascending order, beginning with the DTC with the lowest numerical value. Troubleshoot the DTCs as indicated below:
- DTC 2, 3, 4 and 5 simultaneously: Check for an open in the LT GRN wire between MICU D11 and relay control module J7, LT GRN wire between MICU N28 and combination switch control unit No. 4, LT GRN wire between MICU J4 and driver's MPCS unit A28, and LT GRN wire between MICU N22 and gauge control module B17. If the wire is OK, substitute a known-good driver's under-dash fuse/relay box, under-hood fuse/relay box, gauge control module, wiper/washer switch, and driver's MPCS unit one at a time, in that order, and recheck for the DTCs after each substitution.
- DTC 1 only: Go to MICU input test MICU Input Test.
- DTC 2 only (no other DTCs present): Go to the relay control module input test Relay Control Module Input Test. If all inputs are OK, substitute a known-good relay control module and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit.
- DTC 3 only (no other DTCs present): Go to the driver's MPCS unit input test Drivers MPCS Unit Input Test. If all inputs are OK, substitute a known-good driver's MPCS unit and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit.
- DTC 4 only (no other DTCs present): Go to the combination switch control unit input test Combination Switch Control Unit Input Test. If all inputs are OK, substitute a known-good wiper/washer switch and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit.
- DTC 5 only (no other DTCs present): Go to the gauge control module input test Gauge Control Module Input Test. If all inputs are OK, substitute a known-good gauge control module and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit.
8. Check for B-CAN DTCs indicated by the gauge control module Reading and Clearing Diagnostic Trouble Codes.
Are any DTCs indicated?
YES -
Go to step 9.
NO -
Go to step 11.
9. Record all DTCs and sort them by type using the DTC Troubleshooting.
10. Troubleshoot the DTCs in these order:
- Battery voltage DTCs
- Internal error DTCs
- Loss of communication DTCs (begin with the lowest number first; for example, if DTC B1005 and B1008 are retrieved, troubleshoot B1005 first)
- Signal error DTCs
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 and rear map lights will flash two times quickly and then go off.
NOTE: If the MPCS connector is disconnected for too short or too long of a time, or the ignition switch is turned to LOCK (0), the system will return 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 map lights will blink once. If the circuit is faulty, there will be no indication.
MICU
RELAY CONTROL MODULE
COMBINATION SWITCH CONTROL UNIT
DRIVER'S MPCS UNIT
GAUGE CONTROL MODULE
POWER SEAT CONTROL UNIT
Do the map lights indicate proper switch operation?
YES -
Go to function and input test for the system related to the failure.�
NO -
Repair the open, short, or replace the faulty switch.�