Acura TSX / Honda Accord CL. Manual — part 152

Fig. 39: Multiplex Integrated Control System Wiring Diagram (2 Of 2)

DTC TROUBLESHOOTING

DTC B1000: COMMUNICATION BUS LINE ERROR

1. Clear the DTCs using the HDS.

2. Cycle the ignition switch to OFF and then back ON.

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX

3. Check for DTCs using the HDS.

Is DTC B1000 indicated?

YES: Go to step 4.

NO: Intermittent failure. The communication bus line is OK at this time. Check for loose or
poor connections. If the connections are good, check the battery condition and the charging
system. See GENERATORS & REGULATORS .

4. Check for DTCs using the HDS.

Are DTC B1005, B1006, B1007, B1008, B1009 and B1010 indicated?

YES: Go to step 5.

NO: Replace the MICU.

5. Disconnect each control unit one at a time. Clear the DTC, then recheck for DTCs after each unit is

disconnected.

z

Gauge control module

z

Relay control module

z

Driver's multiplex control unit

z

Climate control unit

z

Combination switch control unit

Is DTC B1000 indicated with each unit disconnected?

YES: Check for a short to power or ground in the communication circuit by
disconnecting the harness at each control unit and testing for continuity to ground or
short to power. Repair or replace the harness as necessary.

NO: Replace the control unit that was disconnected, and did not set DTC B1000.

DTC B1050, B1100, B1150, B1200, B1250: COMMUNICATION BUS LINE ERROR

1. Clear the DTCs using the HDS.

2. Cycle the ignition switch to OFF and then back ON.

3. Check for DTCs using the HDS.

Are DTC(s) B1050, B1100, B1150, B1200 or B1250 indicated?

YES: Go to step 4.

NO: Intermittent failure, the system is OK at this time.

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX

Fig. 40: DTC Table

4. Check for DTCs using the HDS.

Is DTC(s) B1000 indicated?

YES: Troubleshoot DTC B1000.

NO: If DTC B1050 is indicated, replace the relay control module. If DTC B1100 is
indicated, replace the door multiplex control unit. If DTC B1150 is indicated, replace the
gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ). If DTC
B1200 is indicated, replace the climate control unit. If DTC B1250 is indicated, replace the
combination switch control unit.

DTC B1001, B1002: MULTIPLEX INTEGRATED CONTROL UNIT (MICU) INTERNAL ERROR

1. Clear the DTCs using the HDS.

2. Cycle the ignition switch to OFF and then back ON.

3. Operate the door lock (LOCK/UNLOCK).

4. Check for DTCs using the HDS.

Is DTC B1001 or B1002 indicated?

YES: Faulty MICU; replace the under-dash fuse/relay box.

NO: Intermittent failure, the MICU is OK at this time. Check for loose or poor connections.
If the connections are good, check the battery condition and the charging system. See
GENERATORS & REGULATORS .

DTC B1005: MICU LOST COMMUNICATION WITH RELAY CONTROL MODULE

1. Clear the DTCs using the HDS.

2. Cycle the ignition switch to OFF and then back ON.

3. Check for DTCs using the HDS.

Is DTC B1005 indicated?

YES: Go to step 4.

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX

NO: Intermittent failure, the relay module is OK at this time. Check for loose or poor
connections. If the connections are good, check the battery condition and the charging
system. See GENERATORS & REGULATORS .

4. Check for DTCs in the gauge control module using the HDS.

Is DTC B1158 indicated?

YES: Go to Relay Control Module Input Test (see RELAY CONTROL MODULE INPUT
TEST ).

NO: Check for an open, or a short to power or ground in the communication circuit between
the MICU and the relay control module. If the circuit is OK, replace the MICU. If the circuit
is bad, repair the open, or short to power or ground.

DTC B1006: MICU LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT DOOR
LOCK SWITCH MESSAGE

1. Clear the DTCs using the HDS.

2. Cycle the ignition switch to OFF and then back ON.

3. Check for DTCs using the HDS.

Is DTC B1006 indicated?

YES: Go to step 2.

NO: Intermittent failure, the door multiplex control unit is OK at this time. Check for loose
or poor connections. If the connections are good, check the battery condition and the
charging system. See GENERATORS & REGULATORS .

4. Check for DTCs in the gauge control module and relay module using the HDS.

Is DTC B1160 and B1058 indicated?

YES: Go to Door Multiplex Control Unit Input Test (see DOOR MULTIPLEX
CONTROL UNIT INPUT TEST ).

NO: Check for an open, or a short to power or ground in the communication circuit between
the MICU and the door multiplex control unit. If the circuit is OK, replace the MICU. If the
circuit is bad, repair the open, or short to power or ground.

DTC B1007: MICU LOST COMMUNICATION WITH THE COMBINATION SWITCH CONTROL
UNIT (HEADLIGHT SWITCH MESSAGE)

1. Clear the DTCs using the HDS.

2. Cycle the ignition switch to OFF and then back ON.

3. Check for DTCs using the HDS.

Is DTC B1007 indicated?

YES: Go to step 4.

NO: Intermittent failure, the MICU is OK at this time. Check for loose or poor connections.
If the connections are good, check the battery condition and the charging system. See
GENERATORS & REGULATORS .

4. Check for DTCs of the gauge control module and relay control module using the HDS.

2004 Acura TSX

2004 ACCESSORIES & EQUIPMENT Multiplex Integrated Control System - TSX