## Multiplex Control System

#### Troubleshooting (cont'd)

22-276

12. Shift to the sleep mode:
    Turn the ignition switch OFF.
    If the control unit receivers no inputs from the inputs listed below, it will go into the sleep mode after about 20 seconds.

Multiplex Control Unit
Taillight relay Driver's door switch Front passenger's door switch Left rear door switch Right rear door switch

Tailgate latch switch (5-door)

Trunk latch switch

Driver's door key cylinder switch (LOCK/UNLOCK)

Driver's door lock switch (LOCK/UNLOCK)

Passenger's door lock switch (LOCK/UNLOCK)

Keyless communication line

13. Confirm the sleep mode:
    Check for voltage on the YEL and WHT/GRN wires. There should be battery voltage in the sleep mode. Check the parasitic draw at the battery while shifting into the sleep mode. Amperage should change from about 70 through 80 mA to less than 10 mA.

14. Shift to the wake up mode:

When the ignition switch is turned ON (II), the multiplex control unit, gauge assembly and ECM/PCM wake up at the same time without ''talking'' to each other through the communication lines. When any switch in the multiplex system is turned on, it wakes up its related control unit which, in turn, wakes up the other units.

After confirming the sleep mode, look in the following table for the switch most closely related to the problem. Operate that switch and see if its control unit wakes up.

NOTE: If any control unit is faulty and will not wake up, several parts of the system will malfunction at the same time.

In the table below, the control unit is followed by a list of the switches and input signals that can wake it up.

Multiplex Control Unit No. 9 (10 A) under - hood fuse
Communication lines (ECM/PCM, Gauge assembly)
Taillight relay Driver's door switch Front passenger's door switch Left rear door switch Right rear door switch

Driver's door key cylinder switch (LOCK/UNLOCK)

Driver's door lock knob switch (LOCK/UNLOCK)

Driver's door lock switch (LOCK/UNLOCK)

Tailgate key cylinder switch (LOCK/UNLOCK) (5 - door)

Front passenger's door key cylinder switch (UNLOCK)

Keyless communication line

Ignition key switch

Is the wake-up function OK?

YES – Intermittent failure; the system is OK at this time.

NO – Test the multiplex control unit inputs (see page 22-277).