Acura RL (1996-2004 year). Manual — part 644
Multiplex Control System
Component Location Index
IGNITION KEY LIGHT
Replacement, page
MULTIPLEX CONTROL UNIT (PASSENGER'S)
(Has built-in the beeper)
MULTIPLEX CONTROL UNIT (DOOR)
(built into the power window
master switch)
MULTIPLEX CONTROL
INSPECTION CONNECTOR
[Wire color: PNK/BLK and BLK]
MULTIPLEX CONTROL UNIT (DRIVER'S)
Description
The multiplex control system is composed of three control units (located in the driver's side kick panel, passenger's side
kick panel, and driver's door).
These three control units send multiplex signals over shared wires,reduce the number of control units and wire harness
weight, and improves the quality of electrical functions by means of the integrated circuits. This system has a built-in self-
diagnosis function.
Main Menu
Table of Contents
System Functions
• Multiplex Control System (Multiplex function, Wake up/sleep function, Fail-safe function, Self-diagnosis function*)
*: Self-diagnosis function mode 1 is the self-diagnosis for the multiplex control system.
Self-diagnosis function mode 2 is the failure diagnosis for the input line of each system.
• Integrated Control System (Engine oil pressure indicator flasher circuit, Key-in reminder circuit, Light-on reminder circuit,
Seat belt reminder circuit)
• Dash Lights Brightness Control
• Entry Light Control System
• Rear Window Defogger
• Trunk lid Opener
• Power Door Locks (with keyless entry system)
• Power Window (with key-off timer operation)
• Wiper/washers (with speed respondent intermittent wiper)
• Security Alarm System
• Interlock System (see
Multiplex Communication System
Multiplex Communication Functions
• To reduce the number of wire harnesses, digital signals are sent via shared multiplex communication lines rather than
sending normal electrical signals through individual wires.
• The input signals from each switch are converted to digital signals at the central processing unit (CPU). The digital
signals are sent from the transmitter unit to the receiver unit as serial signals.
• The transmitted signal is converted to a switch signal at the receiver unit, and it operates the related component.
• There are exclusive communication lines between each of the multiplex control units:
Door Driver's (from the door to the driver's multiplex control units) Wire color: BRN/YEL
Driver's Passenger's (from the driver's to the passenger's multiplex control units) Wire color: BRN/WHT
Passenger's Driver's (from the passenger's to the driver's multiplex control units) Wire color: RED/YEL
• The control units always communicate via these lines when the system is operating, and they stop communicating
when the system is OFF.
Wake-up and Sleep Functions
• The multiplex control system has "wake-up" and "sleep" functions to decrease parasitic draw on the battery when the
ignition switch is OFF.
• In the sleep mode, the multiplex control unit stops the functions (communication and CPU control) when it is not nec-
essary for the system to operate.
• As soon as any operation is done (for example, a door is unlocked), the related control unit in the sleep mode wakes up
and begins to function at once. This control unit also sends a wake-up signal to the other control units via the commu-
nication lines.
• When the ignition switch is turned OFF, there is about a 30 second delay before the control units go from the wake-up
mode to the sleep mode.
• If any door is open, the sleep mode will not function.
Fail-safe Functions
• To prevent improper operation, the multiplex control system has a fail-safe function. In the fail-safe mode, the output
signal is fixed when any part of the system malfunctions (for example, a faulty control unit or communication line).
• Each control unit has a hardware fail-safe function that fixes the output signal when there is any CPU malfunction and
a software fail-safe function that ignores the signal from the malfunctioning control unit and allows the system to
operate normally.
Main Menu
Table of Contents
Multiplex Control System
Troubleshooting Guide
A problem has been detected
with at least one of the multiplex
control system functions.
Check the No. 13, 17, 44, and 56
fuses.
Are the fuses OK?
Find and repair cause of the
blown fuse.
NO
YES
Check the power and ground sys-
tem (see page
).
Is the power and ground
system OK?
Repair the power and ground
system.
NO
YES
Check the self-diagnosis function
(Mode 1) for a diagnostic trouble
code (DTC) (see page
).
Find and repair the cause of the
DTC.
YES
Is a DTC indicated?
NO
Check the wake-up function (see
page
).
NO
Repair the wake-up function.
Is the wake-up function OK?
YES
Troubleshoot the individual sys-
tem function that had a problem.
Main Menu
Table of Contents
Power and Ground Test
Multiplex Control Unit (Door):
1. Remove the driver's door panel, and disconnect the 20P connector from the door unit.
2. Inspect the connector and socket terminals to be sure they are all making good contact.
• If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
• If the terminals look OK, make the following input tests at the connector.
If a test indicates a problem, find and correct the cause, then recheck the system.
If all the input tests prove OK, the power window master switch must be faulty; replace it.
MULTIPLEX CONTROL UNIT (DOOR)
DRIVER'S
DOOR
PANEL
2OP
CONNECTOR
Wire side of
female terminals
WHT/YEL
GRN/WHT*
1
WHT/BLK*
2
BLK
BLK*
1
Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
WHT/YEL
GRN/WHT
or
WHT/BLK
BLK
Under all conditions
Ignition switch ON (II)
Under all conditions
Check for voltage to ground:
There should be battery voltage.
Check for voltage to ground:
There should be battery voltage.
Check for continuity to ground:
There should be continuity.
• Blown No. 56 (7.5 A) fuse in the
under-hood fuse/relay box
• An open in the wire
• Blown No. 17 (20 A)*
1
or No. 17
(7.5 A)*
2
fuse in the under-dash
fuse/relay box
• Faulty power window relay
• An open in the wire
• Poor ground (G401, G402)
• An open in the wire
*1: '96 -97 models
*2: '98 - 00 models
Main Menu
Table of Contents
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст