B2188
DTC B2188: Communication Line (UART Line) Circuit OpenNOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test mode A.
1. Clear the DTCs with the HDS.
2. Turn the ignition switch OFF and then back ON (II).
3. Open and close the each window by operating the front passenger's, left rear, and right rear window switches.
4. Check for DTCs with the HDS.
Is DTC B2188 indicated, and does the any window fail to open or close?
YES - Go to step 5.
NO - Intermittent failure. The UART line is OK at this time.
5. Turn the ignition switch OFF.
6. Disconnect these connectors:
- Driver's MPCS unit connector A (40P)
- Power window master switch 6P connector
- Passenger's MPCS unit connector A (28P)
- Left rear window switch 14P connector
- Right rear window switch 14P connector
7. Connect driver's MPCS unit connector A (40P) terminal No. 8 to body ground with a jumper wire.
8. Check for continuity between passenger's MPCS unit connector A (28P) terminal No. 4 and body ground.
Is there continuity?
YES - Go to step 9.
NO - Repair an open in the wire, or replace the faulty passenger's under-dash fuse/relay box.
9. Check for continuity between right rear window switch 14P connector terminal No. 2 and body ground.
Is there continuity?
YES - Go to step 10.
NO - Repair an open in the wire, or replace the faulty passenger's under-dash fuse/relay box.
10. Check for continuity between left rear window switch 14P connector terminal No. 2 and body ground.
Is there continuity?
YES - Go to step 11.
NO - Repair open in the wire.
11. Remove the jumper wire from the driver's MPCS unit connector A (40P).
12. Check for continuity between driver's MPCS unit connector A (40P) terminal No. 8 and power window master switch 6P connector terminal No. 6.
Is there continuity?
YES - Go to step 13.
NO - Repair an open in the wire.
13. Substitute a known-good power window master switch, and do the power window control unit learning procedure.
14. Connect these connectors:
- Driver's MPCS unit connector A (40P)
- Passenger's MPCS unit connector A (28P)
- Left rear window switch 14P connector
- Right rear window switch 14P connector
15. Turn the ignition switch ON (II).
16. Clear the DTCs with the HDS.
17. Open and close the each window by operating the power window master switch.
18. Check for DTCs with the HDS.
Is DTC B2188 indicated?
YES - Go to step 19.
NO - The original power window master switch is faulty; replace it.
19. Turn the ignition switch OFF.
20. Substitute a known-good passenger's MPCS unit.
21. Turn the ignition switch ON (II).
22. Clear the DTCs with the HDS.
23. Open and close the front passenger's window by operating the front passenger's window switch.
24. Check for DTCs with the HDS.
Is DTC B2188 indicated?
YES - Go to step 25.
NO - The original passenger's MPCS unit is faulty; replace it.
25. Turn the ignition switch OFF.
26. Substitute a known-good left rear window switch.
27. Turn the ignition switch ON (II).
28. Clear the DTCs with the HDS.
29. Open and close the left rear window by operating the left rear window switch.
30. Check for DTCs with the HDS.
Is DTC B2188 indicated?
YES - Go to step 31.
NO - The original left rear window switch is faulty; replace it.
31. Turn the ignition switch OFF.
32. Substitute a known-good right rear window switch.
33. Turn the ignition switch ON (II).
34. Clear the DTCs with the HDS.
35. Open and close the right rear window by operating the right rear window switch.
36. Check for DTCs with the HDS.
Is DTC B2188 indicated?
YES - Replace the driver's MPCS unit.
NO - The original right rear window power switch is faulty; replace it.