Acura TSX / Honda Accord CL. Manual — part 58

Fig. 15: Connecting The MPCS Service Connector To The MCIC Socket In The Under-Dash
Fuse/Relay Box

5. Wait 5 seconds, then watch the ceiling light.

6. If there is a DTC, the ceiling light and ignition switch light will blink, pause, then repeat the DTC as long

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX

as the ignition switch 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-diagnosis Mode 1, the ceiling light 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 from the DTC with the lowest numerical value. Troubleshoot the DTCs as indicated
below:

z

DTC 2, 3, 4 And 5 Simultaneously: Check for an open in the BLU wire between multiplex
integrated control unit D11 and relay module J7, BRN/RED wire between multiplex integrated
control unit J4 and door multiplex control unit No. 16, LT GRN wire between multiplex integrated
control unit X27 and combination switch control unit No. 4, BRN/YEL wire between multiplex
integrated control unit N28 and gauge B25. If the wire is OK, substitute a known-good under-dash
fuse/relay box (multiplex integrated control unit), under-hood fuse/relay box, power window
master switch, wiper/washer switch and gauge one at a time, in that order, and recheck for the
DTCs after each substitution.

z

DTC 1 Only: Go to MICU input test (see MULTIPLEX INTEGRATED CONTROL UNIT
INPUT TEST ).

z

DTC 2 Only (No Other DTCs Present): Go to the relay module input test. If all inputs are OK,
substitute a known-good relay module and then a MICU, one at a time, and then check for DTCs. If
a DTC recurs after a substitution, replace that unit.

z

DTC 3 Only (No Other DTCs Present): Go to the door multiplex control unit input test. If all
inputs are OK, substitute a known-good door multiplex control unit and then a MICU, one at a
time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit.

z

DTC 4 Only (No Other DTCs Present): Go to the 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.

z

DTC 5 Only (No Other DTCs Present): Go to the 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.

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX

Fig. 16: DTC Table

8. Check for B-CAN DTCs indicated by the gauge control module while still in Test Mode 1.

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 Index.

10. Troubleshoot the DTCs in the following order:

z

Battery voltage DTCs

z

Internal error DTCs

z

Loss of communication DTCs (begin with the lowest number first; for example, if B1006 and
B1059 are retrieved, troubleshoot B1006 first)

z

Signal error DTCs

11. Remove the MPCS service connector from the under-dash fuse/relay box socket for 5-10 seconds, then

re-insert it.

NOTE:

If the MPCS connector is disconnected for too short or too long of a time,
or the ignition switch is turned OFF, the system will return to Test Mode 2.

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX

12. In the table below is a list of 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.

Does the ceiling light 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.

Fig. 17: MICU Table

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX