2006 ACURA CSX keyless

Î
(#')

22-73
Multiplex Integrated Control System
Component Location Index
GAUGE CONTROL MODULE (TACH)
IMMOBILIZER-KEYLESS CONTROL UNIT
(With built-in the receiver)
MICU
(Built into the under-dash fuse/relay box) CLIMATE CONTROL
UNIT
HANDSFREELINK
CONTROL UNIT
Input Test, page 22-271
Input Test, page 22-109 Replacement, page 21-75
Self-diagnostic Function, page 23-368
Input Test, page 23-388
08/08/21 14:24:07 61SNR030_220_0075
ProCarManuals.com
DYNOMITE -2009-

Î
How to display DTCs on the gauge control module (tach)
How to clear the DTC
22-75
No DTCs detectedAll DTCs have been displayed
DTC detected
(the letter and four digit number on the left
represents the DTC, the right two digit is the
unit code.)
While in Test Mode 1, the DTCs which have been detected and stored individually by various B-CAN (Body-controller
Area Network) units, will be shown one by one on the odometer display when the communication between the MICU
and the gauge control module is normal. To scroll through the DTCs, press the select/reset button.
The unit that has stored the code can be identified by the number shown on the multi-information display.
MICU 10
Gauge control module 50
Climate control unit 51
HandsFreeLink control unit 94
Immobilizer-keyless control unit 96
While in Test Mode 1, press and hold down the SELECT/RESET button for more than 10 seconds.
(cont’d)
08/08/21 14:24:07 61SNR030_220_0077
ProCarManuals.com
DYNOMITE -2009-

Loss of Communication DTC cross-reference chart
BUS OFF and Internal Error CodesDTC type Related Unit MICU Gauge ControlModuleClimate Control
Unit HandsFreeLink
Control Unit Immobilizer-
Keyless Control Unit
Transmitting Control Unit Message Receiving Unit/Loss of Communication DTC
MICU Gauge ControlModuleClimate Control
Unit Immobilizer-
Keyless Control Unit
22-76Multiplex Integrated Control System
General Troubleshooting Information (cont’d)
When an ECU on the CAN circuit is unable to communicate with other ECUs on the CAN circuit, one or more of the
control units will set a loss of communications DTC. Use this chart to find the control unit that is not communicating.
1. Find the Transmitting Control Unit that is in the same row as all of the loss of communication DTCs retrieved.
2. Do the input test for the transmitting control unit.
BUS OFF B1000 B1150 B1200 B1750 B1900
ECU (CPU) Error B1001
ECU (EEPROM)
Error B1002 B1152 B1202
ECU (Internal)
Error B1792
MICU RM B1188 HLSW B1155
WIPSW B1156 MICU B1157
DOORSW B1159
DRLOCKSW B1160 B1905
Gauge Control
Module VSP/NE B1011 B1205
A/T B1008 B1906
CDS (SRS) B1032 ECT B1206
ECM/PCM ENG B1168 A/T B1169
ABS or VSA
modulator-
control unit ABS or VSA B1170
TPMS Control
unit TPMS B1173
EPS Control unit EPS B1183
SRS SRS B1187
08/08/21 14:24:07 61SNR030_220_0078
ProCarManuals.com
DYNOMITE -2009-

Climate Control UnitDTC Description DTC typePage
HandsFreeLink Control Unit DTC Description DTC typePage
Immobilizer-Keyless Control Unit DTC Description DTC typePage
22-79
B1200 Communication bus line error (BUS-OFF) Loss of
communication (see page 22-107)
B1202 Climate control unit internal error ( EEPROM error)Internal error (see page 21-28)
B1205 Climate control unit lost communication with the gauge control module (VSP/NE message) Loss of
communication(see page 21-28)
B1206 Climate control unit lost communication with the gauge control module (ECT message) Loss of
communication(see page 21-28)
B1207 Climate control unit lost communication with the gauge control module (ILLUMI message) Loss of
communication(see page 21-28)
B1220 Recirculation control motor circuit short Signal error (see page 21-29)
B1225 In-car temperature sensor circuit open Signal error (see page 21-31)
B1226 In-car temperature sensor circuit short Signal error (see page 21-32)
B1227 Outside air temperature sensor circuit open Signal error (see page 21-33)
B1228 Outside air temperature sensor circuit short Signal error (see page 21-34)
B1229 Sunlight sensor circuit open Signal error (see page 21-35)
B1230 Sunlight sensor circuit short Signal error (see page 21-36)
B1231 Evaporator temperature sensor circuit open Signal error (see page 21-37)
B1232 Evaporator temperature sensor circuit short Signal error (see page 21-39)
B1233 Air mix control motor circuit open Signal error (see page 21-40)
B1234 Air mix control motor circuit short Signal error (see page 21-41)
B1235 Air mix control motor stuck Signal error (see page 21-42)
B1239 Mode control motor circuit open or short Signal error (see page 21-44)
B1240 Mode control motor, linkage, door malfunctionSignal error (see page 21-46)
B1241 Blower motor circuit malfunction Signal error (see page 21-47)
B2983 Recirculation control motor, linkage, door malfunctionSignal error (see page 21-51)
B2986 Recirculation control motor circuit open Signal error (see page 21-52)
B1750 Communication bus line error (BUS-OFF) Loss of
communication (see page 22-107)
B1775 Microphone input/output short to power/open Signal error (see page 23-376)
B1776 Microphone input/output short to ground/open Signal error (see page 23-377)
B1779 HFL switch (HFL talk/HFL back buttons) circuit open/short Signal error (see page 23-379)
B1780 HFL switch (HFL talk/HFL back buttons) circuit short Signal error (see page 23-381)
B1792 HandsFreeLink control unit internal error Internal error (see page 23-382)
B1900 Communication bus line error (BUS-OFF) Loss of
communication (see page 22-108)
B1905 Immobilizer-keyless control unit lost communication with the MICU (DRLOCKSW message) Loss of
communication(see page 22-317)
B1906 Immobilizer-keyless control unit lost communication with the gauge control module (A/T message) Loss of
communication(see page 22-318)
B1925 Ignition key switch signal error Signal error (see page 22-319)
08/08/21 14:24:08 61SNR030_220_0081
ProCarManuals.com
DYNOMITE -2009-

Î
(#')

µµ
µ
Body Controller Area Network (B-CAN) and Fast Controller Area Network (F-CAN)
22-80 Multiplex Integrated Control System
System Description
GAUGE CONTROL MODULE (TACH)
CAN H CAN L
MICU
ECM/PCM
(F-CAN)
(B-CAN)UNDER-DASH FUSE/RELAY BOX
DATA LINK CONNECTOR
SRS UNIT
ABS MODULATOR-CONTROL UNIT*1
VSA MODULATOR-CONTROL UNIT*2
YAW RATE-LATERAL
ACCELERATION SENSOR*2
EPS CONTROL UNIT
TPMS CONTROL UNIT*3






 F-CAN
TRANSCEIVER
B-CAN
TRANSCEIVER
IMMOBILIZER-
KEYLESS CONTROL
UNITCLIMATE
CONTROL
UNIT
HANDSFREELINK
CONTROL UNIT*4
*1: ’06 07 Touring and Premium models
*2: ’07 TYPE S and ’08 09 models
*3: ’08 09 models
*4: ’09 model with navigation system
The body controller area network (B-CAN) and the fast controller area network (F-CAN) share information between
multiple electronic control units (ECUs). B-CAN communication moves at a slower speed (33.33 kbps) for convenience
related items and for other functions. F-CAN information moves at a faster speed (500 kbps) for ‘‘real time’’ functions
such as fuel and emissions data. To allow both systems to share information, the gauge control module translates
information from B-CAN to F-CAN and from F-CAN to B-CAN.
 The single wire method is used between the units not requiring the communication to move at a fast speed.
 Using a single wire method reduces the number of the wires used on the body controller area network.
08/08/21 14:24:08 61SNR030_220_0082
ProCarManuals.com
DYNOMITE -2009-

MICU Control Functions Index
SystemFunction
22-82Multiplex Integrated Control System
System Description (cont’d)
The MICU (built into the under-dash fuse/relay box) is one of the B-CAN components. The MICU controls many
systems related to the body controller area and security system, and also works as a gateway to the diagnose the
other B-CAN connected ECUs with the HDS.
Refer to the each system circuit diagram in detail.
Multiplex Control Sends the switch input signal information to the MICU and outputs the information. The MICU controls the ECUs electric load and communication based upon the information
received the B-CAN.
On-Board Diagnosis The MICU has a gateway function which sends the results of the MICU internal diagnosis and the B-CAN connected ECUs diagnosis to the HDS.
Self-Diagnosis Test mode 1 diagnoses the communication line between the MICU and B-CAN connected unit. Test mode 2 checks the switch inputs connected to the MICU.
Interior Light(s) The MICU controls the interior lights ON, OFF and dimming based upon the information of the related switches and/or the B-CAN related information.
Sleep Function The MICU has a sleep function, which it enters during the power down mode.
The MICU also controls the function of these circuits:  Entry lights control (map lights and ceiling light)
 Exterior lights control (including the daytime running lights control)
Horn
 Interlock system
 Key-in reminder
 Keyless entry
 Lights-on reminder
 Power door locks
 Power window key-off timer
 Seat belt reminder
 Security alarm
 Turn signal/hazard flasher
 Wiper/washer
08/08/21 14:24:08 61SNR030_220_0084
ProCarManuals.com
DYNOMITE -2009-

Î
Self-diagnostic Function
22-83
GAUGE CONTROL MODULE
CAN H CAN L B-CAN
B-CAN (33.33 kbps)
F-CAN (500 kbps)
SRS UNIT MICU
ECM/PCM
ABS MODULATOR-
CONTROL UNIT* IMMOBILIZER-
KEYLESS
CONTROL UNIT
K-LINE
DATA LINK
CONNECTOR HDS CLIMATE CONTROL
UNIT
TMPS CONTROL
UNIT* EPS CONTROL
UNIT
NAVIGATION
UNIT
VSA MODULATOR-
CONTROL UNIT*
HANDSFREELINK
CONTROL UNIT*
AUDIO UNIT
YAWRATE-LATERAL
ACCELERATION
SENSOR*
*1: ’06-08 Touring and Premium models
*2: ’07 TYPES and ’08-09 models
*3: ’08-09 models
*4: ’09 model with navigation system
1
3 2
4
2
By connecting the HDS to the data link connector (DLC), the HDS can retrieve the diagnostic results from the MICU via
a diagnostic line called K-LINE. The K-LINE is distinguished from the CAN line, and connected to the CAN related ECUs.
The MICU is a gateway between the HDS and B-CAN related ECUs, and sends B-CAN diagnostic results to the HDS.
When doing a function test with the HDS, the HDS sends an output signal through the K-LINE to the MICU. The MICU
either relays the request to another ECU, or commands the function its self.
(cont’d)
08/08/21 14:24:09 61SNR030_220_0085
ProCarManuals.com
DYNOMITE -2009-

Power Supply Voltage Monitoring Function
Entry Lights Control System
Lighting System (Headlights, Parking Lights, Fog Lights, Side Marker Lights, License Plate
Lights, and Taillights)
Daytime Running Lights
Turn Signal/Hazard Warning Lights
Door Lock Response Operation
Power Window Key-off Operation
InputOutput
Input Output
Input Output
Input Output
Input Output
Input Output
Input Output
22-85
The MICU monitors the power supply voltage (back-up voltage). If the voltage goes below 10 V, the MICU sends a MICU message and will not
store DTCs.
MICU Battery voltage MICU : MICU internal circuit
The MICU controls the ceiling light ON/OFF and dimming based upon input signals from each switch. MICU IG1 power supply Ignition key switch
Driver’s door switch
Front passenger’s door switch
Left rear door switch
Right rear door switch
Driver’s door lock knob switch (LOCK) Interior light
B-CAN Keyless LOCK signal
The MICU contains the relay circuits for the headlight high/low beams and taillights, and controls the lighting system ON/OFF based upon input
signals from the combination light switch. MICU Headlight OFF switch Headlight ON switch
Fog light switch
Dimmer switch
Combination light switch (parking lights, side marker lights,
license plate lights, and taillights)
Passing switch Headlights (low beam)
Headlights (high beam)
Parking lights
Fog lights
Side marker lights
License plate lights
Taillights
The MICU controls the exterior lights as a daytime running lights based upon input signals from each switch. MICU Headlight OFF switch Headlight ON switch
Dimmer switch
Combination light switch (parking lights, side marker lights,
license plate lights, and taillights)
Passing switch Headlights (low beam)
Headlights (high beam)
Parking lights
Slide marker lights
License plate lights
Taillights
B-CAN Transmission range switch (P position)
The MICU controls the turn signal/hazard warning lights based upon input signals from the turn signal and hazard warning switches. MICU IG1 power supply Turn signal switch (left/right)
Hazard warning switch Turn signal lights (left/right)
The MICU controls the door lock actuators based upon B-CAN signals. B-CAN Door lock signals Door lock actuator (LOCK/UNLOCK) Driver’s door lock actuator (UNLOCK)
Trunk lid release actuator
The MICU controls the power windows key-off operation based upon input signals from each switch. MICU IG1 power supply Ignition key switch
Driver’s door switch
Front passenger’s door switch Power window key-off timer
(cont’d)
08/08/21 14:24:09 61SNR030_220_0087
ProCarManuals.com
DYNOMITE -2009-