Acura 2002 RSX Service Manual page 1330

Multiplex Control System
Troubleshooting (cont'dl
Multiplex Sleep Mode Test
l. Connect the positive lead of a voltmeter to terminal
10 of the under-dash fuse/relay box connector E
(YEL) or K (WHT/GRN) and the negative lead to
body ground.
2, Connect an ammeter between the negative battery
cable and the negative battery post.
3. Remove the special tool from the mulliplex
inspection connector.
4. Close the doors, the hatch, turn the headlights off,
turn off the ignition switch and remove the key.
5. Within I minute, the voltage on the communication
w i r e ( E 1 0 o r K l 0 ) s h o u l d c h a n g e f r o m a b o u t 4 - 1 0
V to battery voltage and the amperage at the
negative battery terminal should drop from about
70 80 mA to less than 10 mA.
6. Record your findings and go to the Multiplex Wake-
up Test.Multiplex Wake-up Test.
22-178
Multiplex Wake-up Test
1, From the sleep mode, wake-up the multiplex
system by performing one of the following
operaUons;
Operation Method used for wake uD
Cycle ignition
switch on
AII multiplex units wake up
simultaneously (regardless of
abilitv to communicate)
T u r n
combination
light switch to
p a r k i n g l i g h t
position
Multiplex control unit wakes
up the other units via
communication lines.
Open the driver's
door
Multiplex control unit wakes
up the other units via
c o m m u n i c a t i o n l i n e s .
2. As the system shifts to its active (wake-up) mode,
communication wire voltage will return to 4 10 V
and the batterv terminal current will return to 70
80 mA.
3. lf the system does not go into sleep mode or wake-
up properly, perform the Multiplex Control Unit
Input Test (see page 22-'1791.
NOTE: lf multiple circuits fall to respond in the
mode 2 tests and/or the multiplex circuit falls to go
into sleep mode or wake-up, it may mean that a
control unit failed without triggering a DTC in mode
1. Perform the Multiplex Control Unit Input Test
(see page 22-179).
lf the input test confirms that all the inputs are
working properly,substitute a known-good
multiplex control unit, gauge assembly or ECM/
PCM one at a time. lf after swapping one of the
above components the system works properly,
replace the original component, it is faulty.