Multiplex Integrated Control System: Other Acura TL IV facelift

Using the HDS (Preferred Method)

Connect the HDS to the Data Link Connector (DLC).

Note. There are two ways to read B-CAN code with the HDS.

First method; On the HDS, first select BODY ELECTRICAL, then select the subsystem that relates to the problem (for example: door locks, keyless, security, etc.), and then last, select the DTCs.

Second method; Ground the SCS circuit with the HDS, then read the DTCs displayed in the multi-information display (MID) in the gauge control module, then go to B-CAN SYSTEM DIAGNOSIS TEST MODE A .

How to Display DTCs on the MID of the Gauge Control Module

Enter the B-CAN System Diagnosis Test Mode 1 (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS) ). While in Test Mode 1, with normal communication between the MICU and gauge control module, the DTCs which have been detected and stored individually by various B-CAN (Body-Controller Area Network) units are shown one by one on the multi-information display. To scroll through the DTCs, press the SEL/RESET button.

Scheme 12

The control unit that has stored the code can be identified by the number shown after the letters "PA" on the multi-information display (MID).

How to Clear DTCs

1. Enter the B-CAN System Diagnosis Test Mode 1 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)»(ref-512388-S33596282742012103100000) ).
2. While in Test Mode 1, press and hold down the SEL/RESET button for at least 10 seconds to clear the DTCs.

Body Controller Area Network (B-CAN) and Fast Controller Area Network (F-CAN)

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 (125 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 and relays the information from B-CAN to F-CAN and from F-CAN to B-CAN. This is called the Gateway Function.

Scheme 13

Gateway Function

The gauge control module acts as a gateway to allow both systems to share information. The gauge control module translates and relays the information from B-CAN to F-CAN and from F-CAN to B-CAN.

Scheme 14

Network "Loss of Communication" Error Checking Function

The ECUs on the CAN circuit send messages to each other. If there are any communication malfunctions on the network, the multi information display (MID) on the gauge control module can indicate the error messages by entering the gauge control module self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

Scheme 15

Self-Diagnostic Function (On-Board Diagnosis)

By connecting the HDS to the data link connector (DLC), the HDS can retrieve the diagnostic information from the driver's MICU via a diagnostic line called the K-LINE. The K-LINE is a separate communication line from the CAN lines, but it is connected to most of the CAN related ECUs. The driver's MICU is a gateway between the HDS and B-CAN related ECUs, and sends B-CAN diagnostic information to the HDS. When doing a function test with the HDS, the HDS sends an output signal through the K-LINE to the driver's MICU. The driver's MICU either relays the request to another ECU, or commands the function itself.

Scheme 16

Wake-Up and Sleep Function

The multiplex integrated control system has wake-up and sleep functions to decrease parasitic draw on the battery when the ignition switch is at LOCK (0), or the engine start/stop button has been pressed to select the OFF mode.

1. In the sleep mode, the multiplex integrated control system stops functioning (communication and CPU control) when it is not necessary for the system to operate.
2. As soon as any operation is requested (for example, a door is unlocked), the related control units in sleep mode immediately wake up and begin to function.
3. When the ignition switch is turned to LOCK (0), or the engine start/stop button is pressed to select the OFF mode, and the driver's door is opened, then closed, there is a delay of about 40 seconds before the control unit goes from wake-up mode to sleep mode.
4. The sleep mode function if any door is open or will not occur if a key is in the ignition switch.
5. Electrical draw is reduced from 200 mA to less than 35 mA when in sleep mode. NOTE: Sleep and Wake-Up Mode Test (see «SLEEP AND WAKE-UP MODE TEST»(ref-512388-S25326986732012103100000) ).

Fail-Safe Function

To prevent improper operation, the MICUs have 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 a CPU malfunction, and a software fail-safe function that ignores the signal from a malfunctioning control unit, which allows the system to continue operating normally.

When a CPU problem or an abnormal power supply voltage is detected, the MICUs move to the hardware fail-safe mode, and each system output load is set to the pre-programmed fail-safe value.

Software Fail-Safe Control

When any of the data from the B-CAN circuit cannot be received within a specified time, or an unusual combination of data is recognized, the MICUs move to the software fail-safe mode. The data that was not received is forced to a pre-programmed value.

Power Supply Voltage Monitoring Function

The driver's MICU monitors the power supply voltage (back-up voltage). If the voltage drops below 10 V, the driver's MICU does not store DTCs.

Entry Lights Control System (Ceiling Lights, Map Lights, Ignition Key Light)*

The driver's MICU controls the interior lights and ignition key light ON/OFF based on input signals from each switch.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Trunk Light

The driver's MICU controls the trunk light based on input from the trunk lid latch switch.

Collision Detection Signal (CDS)

The driver's MICU controls the door lock actuators based on IG1 and SRS (CDS) inputs.

Key Interlock (A/T)

The driver's MICU controls the key interlock solenoid based on ignition switch ACCESSORY (I) position, the transmission range switch P position, and the park pin switch inputs.

Combination Light Switch

The driver's MICU controls the lighting system based on inputs from the combination light switch.

Daytime Running Lights

The driver's MICU controls the headlights as daytime running lights based on inputs from each switch.

Fog Lights

The driver's MICU controls fog lights based on inputs from the fog light switch.

Headlight Auto OFF Function*

The driver's MICU controls the lighting system based on inputs from each switch.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Turn Signal/Hazard Warning Lights

The driver's MICU controls the turn signal/hazard warning lights based on inputs from the turn signal switch and the hazard warning switch.

Courtesy Light (Driver's Side)

The driver's MICU controls the driver's lights based on input from the driver's door switches.

Wiper

The driver's MICU controls the wiper based on inputs from each switch.

Driver's Power Window Relay

The driver's MICU controls the power windows based on inputs from each switch.

Keyless Answer Back*

The driver's MICU controls the lighting system and horns based on keyless signals sent by B-CAN.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Security Answer Back*

The driver's MICU controls the lighting system and horns based on keyless signals sent by B-CAN.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Power Door Locks*

The driver's MICU controls the door lock actuators based on the inputs from each switch.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Keyless Entry System*

The driver's MICU controls the door lock actuators based on the input signals from each switch.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Security Alarm System

The driver's MICU controls the lighting system and horns based on inputs from each switch and B-CAN data.

The passenger's MICU monitors the power supply voltage (back-up voltage). If the voltage drops below 10 V, the passenger's MICU does not store DTCs.

Courtesy Light (Passenger's Side)

The passenger's MICU controls the front passenger lights is based on input from the front passenger door switch.

Power Door Locks (LOCK)*

The passenger's MICU controls the front passenger's side door lock actuators based on inputs from the driver's MICU.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Power Door Locks (UNLOCK)*

The passenger's MICU controls the front passenger's side door lock actuators based on inputs from the driver's MICU.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

Exterior Lights

The passenger's MICU controls the front passenger's side headlight, and parking lights based on inputs from the driver's MICU.

Automatic Lighting*

The passenger's MICU controls the headlights and the parking lights based on inputs from the automatic lighting sensor.

*: This system can be customized in the multi-information display (MID) to suit the client's needs. For more information about customizing system options, refer to the Owner's Manual.

The passenger's MICU controls fog lights based on inputs from the fog light switch.

HDS Inputs and Function Tests

Certain inputs happen so quickly that the Data List on the HDS cannot update fast enough. Hold the switch that is being tested while monitoring the Data List. This should give the HDS time to update the signal on the Data List.

Because the HDS software is updated to support the release of newer vehicles, it is not uncommon to see system function tests that are not supported.

Make sure that the most current HDS software is loaded.

INPUT

FUNCTION TEST

Troubleshooting - B-CAN System Diagnosis Test Mode A

Check the ECM/PCM for DTCs and troubleshoot ECM/PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first, then do this diagnosis if the symptom is related to the B-CAN system.

Scheme 17

1. Compare the symptom with this list of B-CAN related systems: Gauge control module Exterior lights Turn signals Entry light control Interior lights Safety indicators Horns (security and panic) Beepers (key-in, seat belt, lights-on, and parking brake) Power window/moonroof timer Wiper/washer Security Keyless entry Power door locks Key interlock Dashlights brightness Immobilizer Daytime running lights Driving position memory system XM radio AcuraLink HandsFreeLink Climate control Keyless access control BSI system Is the symptom related to the B-CAN system? YES - Go to step 2. NO - Go to the system troubleshooting for the system with the symptom.
2. Connect the HDS to the data link connector (DLC) (A), then turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
3. From the BODY ELECTRICAL SYSTEM SELECT menu, select B-CAN CONTROL UNITS INFORMATION, and then select CHECK CONNECTED CONTROL UNITS listed to see if the following control units are communicating with the HDS. Driver's MICU Passenger's MICU Door multiplex control unit (HDS name: Power Window Unit) Gauge control module Immobilizer-keyless control unit Climate control unit HandsFreeLink control unit Power seat control unit (HDS name: Memory seat control unit) AcuraLink control unit (XM receiver) (HDS name: HIP (Honda Information Platform) Unit) Keyless access control unit (HDS name: Keyless access ECM) BSI control unit NOTE: If a unit is communicating with the HDS, DETECT is displayed. If a unit is not communicating or the vehicle is not equipped, "NOT AVAILABLE" is displayed. The HDS only checks the status one time when BODY ELECTRICAL is selected. To recheck the status after repair, reboot the HDS. Are all control units communicating with the HDS? YES - Go to step 4. NO - If any of the control units are not communicating, go to «B-CAN SYSTEM DIAGNOSIS TEST MODE B»(ref-512388-S36090622382012103100000) . If all units are not communicating or only the driver's MICU is communicating, go to «DTC U1280 TROUBLESHOOTING»(ref-512388-S29553654432012103100000) .
4. Select the system that has the problem from the BODY ELECTRICAL SYSTEM SELECT menu, then select DTCs. Are any DTCs indicated? YES - Go to step 5. NO - If the problem is related to one of the following items, and the system that is malfunctioning does not stop or turn off, go to «B-CAN SYSTEM DIAGNOSIS TEST MODE C»(ref-512388-S04699990642012103100000) . If the problem is related to one of the following items and the system that is malfunctioning does not run or turn on, go to «B-CAN SYSTEM DIAGNOSIS TEST MODE D»(ref-512388-S02156409162012103100000) . Exterior lights Turn signals Entry light control Interior lights Horns (security and panic) Wiper/washer Power window Power door locks If the problem is related to one of the following items, go to the troubleshooting for that individual system. Gauge control module Safety indicators Beepers (key-in, seat belt, lights-on, and parking brake) Security Keyless entry Key interlock Dashlights brightness Navigation system (if equipped) HandsFreeLink Immobilizer Driving position memory system Rear window defogger (climate control) Climate control Keyless access control BSI system
5. Record all DTCs, and sort them by DTC type.
6. Troubleshoot the DTC(s) in this order: Battery voltage DTCs. Internal error DTCs. Loss of communication DTCs. Signal error DTCs.

Troubleshooting - B-CAN System Diagnosis Test Mode B

Do this diagnosis if any of the control units are not communicating (NOT AVAILABLE is displayed on the HDS) as found by the B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

1. Using the HDS, select the system that has the symptom from the BODY ELECTRICAL SYSTEM SELECT menu.
2. Select the DTCs, and then check for loss of communication DTCs. Are any loss of communication DTCs indicated? YES - Go to step 3. NO - Faulty driver's MICU; replace the driver's under-dash fuse/relay box (see «DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL AND INSTALLATION»(ref-512382-S16871187152012103100000) ).
3. Do the power, ground, and communication part of the input test for the unit(s) not communicating with the HDS. Unit not communicating Driver's MICU (see «MICU INPUT TEST»(ref-512388-S32838641322012103100000) ) Gauge control module (see «GAUGE CONTROL MODULE INPUT TEST»(ref-512365-S33173633502012103100000) ) Power control unit (see «RF UNIT REPLACEMENT»(ref-512359-S08700980662012103100000) ) Keyless access control unit (see «CONTROL UNIT INPUT TEST»(ref-512359-S13411722372012103100000) ) Remote slot control unit (see «RF UNIT REPLACEMENT»(ref-512359-S08700980662012103100000) ) Immobilizer-keyless control unit (see «IMMOBILIZER-KEYLESS CONTROL UNIT INPUT TEST»(ref-512357-S34232765202012103100000) ) Passenger's MICU (see «DTC U1283: DRIVER'S MICU LOST COMMUNICATION WITH PASSENGER'S MICU»(ref-512388-S21106758462012103100000) ) Door multiplex control unit (see «POWER WINDOW MASTER SWITCH INPUT TEST»(ref-512398-S12173008922012103100000) ) Climate control unit (see «CLIMATE CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING»(ref-512346-S25606564922012103100000) ) Audio-navigation unit (see «NAVIGATION UNIT CONNECTOR FOR INPUTS AND OUTPUTS»(ref-512386-S24406547882012103100000) ) Power seat control unit (see «POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT»(ref-512417-S42340715432012103100000) ) AcuraLink control unit (see «ACURALINK CONTROL UNIT (XM RECEIVER) CONNECTOR FOR INPUTS AND OUTPUTS»(ref-512416-S05460907162012103100000) ) HandsFreeLink control unit (see «CONTROL UNIT INPUT TEST»(ref-512415-S08346197312012103100000) ) BSI control unit (see «BLIND SPOT INFORMATION SYSTEM (BSI) CONTROL UNIT INPUTS AND OUTPUTS»(ref-512418-S18200655152012103100000) )

Troubleshooting - B-CAN System Diagnosis Test Mode C

Do this diagnosis if a component that is controlled by the B-CAN system does not stop or turn off.

Note. If the component does not turn on, go to B-CAN SYSTEM DIAGNOSIS TEST MODE D . See the B-CAN system unit input/output index for a list of input and output devices and the control units that monitor the input and control the output devices (see HDS INPUTS AND FUNCTION TESTS ).

1. Check for DTCs by selecting the MODE MENU from the HDS. Are any DTCs indicated? YES - Go to «B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-512388-S21704826112012103100000) (see ). NO - Go to step 2.
2. Turn off the switch that controls the malfunctioning component.
3. Select the applicable system from the system MODE MENU, then select DATA LIST, and check the input of the switch that controls the component. Does the HDS indicate the switch is OFF? YES - Go to step 4. NO - Go to step 6 .
4. In the DATA LIST, check the output signal of the malfunctioning component. Is the output signal OFF? YES - Go to step 5. NO - Replace the control unit that controls the device that will not turn OFF.
5. Check the relay that does not stop or turn off, if applicable, then check for a short in the wire between the relay and the component, the relay and control unit, or the component and control unit. Are the relay and the wire harness OK? YES - Replace the control unit that controls the component that will not stop or turn OFF. NO - Replace the relay or repair/replace the wire harness.
6. Check the switch, then check for a short in the wire between the switch and the control unit that monitors the switch. Are the switch and wire harness OK? YES - Replace the control unit that monitors the switch. NO - Replace the switch, or repair/replace the wire harness.

Troubleshooting - B-CAN System Diagnosis Test Mode D

Do this diagnosis if a component that is controlled by the B-CAN system does not run or come on.

Note. If the component does not turn off or stop, go to B-CAN SYSTEM DIAGNOSIS TEST MODE C . See the B-CAN system unit input/output index for a list of input and output devices and the control units that monitor the input and control the output devices (see HDS INPUTS AND FUNCTION TESTS ).

1. Check the fuse of the malfunctioning output device. Is the fuse OK? YES - Go to step 2. NO - Replace the fuse. If the fuse blows again, repair a short to ground on the fuse circuit of the malfunctioning device.
2. Check for DTCs by selecting the MODE MENU from the HDS. Are any DTCs indicated? YES - Go to «B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-512388-S21704826112012103100000) . NO - Go to step 3.
3. Turn ON the switch that controls the malfunctioning component.
4. Select the applicable system from the system MODE MENU, then select DATA LIST, and check output signal for the malfunctioning component. Is there an output signal? YES - Go to step 5. NO - Go to step 9 .
5. Check the relay and ground, then check for an open or a short in the circuit for the malfunctioning component. Is the relay and the circuit OK? YES - Go to step 6. NO - Replace the relay or repair the wire circuit.
6. Do the function test for the malfunctioning component. Does the output device pass the function test? YES - Go to step 7. NO - Replace the component.
7. With the malfunctioning output device connected, connect a voltmeter between the malfunctioning output device and body ground on the wire that the control unit uses to control the output device circuit.
8. Select FUNCTIONAL TEST from the MODE MENU, and do the forced operation test of the malfunctioning component. Is there a change in voltage (12 V to 0 V or 0 V to 12 V)? YES - Inspect the ground for the component. If OK, replace the component. NO - Replace the control unit that controls the malfunctioning component.
9. Select DATA LIST from the system MODE MENU, and make sure the switch signal input for the malfunctioning system indicates a change when operated. Does the switch input indicate ON when the switch is ON? YES - Replace the control unit that controls the malfunctioning component. NO - Go to step 10.
10. Check the switch and its ground (if applicable), then check for an open or a short in the wire between the switch and the control unit that monitors it. Is the switch and the wire harness OK? YES - Replace the control unit that monitors the switch. NO - Replace the switch, or repair/replace the wire harness.

Troubleshooting - B-CAN System Diagnosis Test Mode 1 and Test Mode 2 (without the HDS)

Special Tools Required

MPCS (MCIC) Service Connector 07WAZ-001010A

Test Mode 1

Check the ECM/PCM for DTCs and troubleshoot ECM/PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first, then do this diagnosis if the HDS is not available.

Scheme 18

1. Check the No. 15(10 A) fuse in the under-hood fuse/relay box and the No. 12 (7.5 A) fuse in the driver's under-dash fuse/relay box. Are the fuses OK? YES - Go to step 2. NO - Replace the fuses. If the fuse blows again, repair the short to ground on the fuse circuit(s).
2. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(ref-512381-S11938601542012103100000) ).
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and move the interior lights switch to the DOOR position.
4. Connect the MPCS service connector (A) to the MICU service check connector socket (B) in the driver's under-dash fuse/relay box.
5. Wait 5 seconds, and watch the front individual map lights and rear individual map lights. When the front individual map lights and rear individual map lights flash quickly once and then goes off, the system is in Test Mode 1.
6. Check for B-CAN DTCs indicated by the multi-information display (MID) on the gauge control module while still in Test Mode 1. Press the SEL/RESET button to display the next code. After you get to the last code, the display shows END. If no DTCs are stored, the display will read NO (see «HOW TO DISPLAY DTCS ON THE MID OF THE GAUGE CONTROL MODULE»(ref-512388-S26957250722012103100000) ). NOTE: If the test times out, remove the MPCS service connector, turn the ignition switch to LOCK (0), and repeat steps 3 and 4 . Are any DTCs indicated? YES - Go to step 7. NO - Go to step 9 .
7. Record all DTCs and troubleshoot them in this order: Battery voltage DTCs Internal error DTCs Loss of communication DTCs Signal error DTCs
8. Clear the DTCs by pressing and holding the SEL/RESET button for about 10 seconds.
9. You will hear a beep to confirm the codes have been cleared. Operate the devices that failed, and recheck for codes. Test Mode 2
10. Remove the MPCS service connector from the driver's under-dash fuse/relay box MICU service check connector socket for 5-10 seconds, then re-insert it to enter Mode 2. When the system enters Mode 2, the front individual map lights and rear individual map lights flash two times quickly and then goes off. NOTE: If the MPCS service connector is disconnected for too short or too long of a time, or if the ignition switch is turned to LOCK (0), or if the vehicle is in OFF mode, the systems returns to Test Mode 1.
11. The following tables list the circuits that can be checked in Test Mode 2. Operate the switch that is most closely related to the problem. If the circuit is OK, the front individual map lights and rear individual map lights blink once. If the circuit is faulty, there is no indication. DRIVER'S MICU Item Brake pedal position switch (ON) Driver's door switch Left rear door switch Trunk lid latch switch Fog light switch Left rear door lock knob switch (UNLOCK) Wiper switch (HI/LO) Wiper switch (INT/LO) Wiper switch (MIST) Washer switch Wiper intermittent dwell time controller Turn signal switch (LEFT) Turn signal switch (RIGHT) Hazard warning switch (ON) Headlight switch (AUTO) Headlight switch (ON) Headlight switch (OFF) Lighting switch (ON) Dimmer switch (ON) Passing switch (ON) Trunk lid opener main switch Trunk lid outer handle switch Transmission range switch (P) (A/T) Ignition key switch Security hood switch Windshield wiper motor park position (Auto stop) Driver's seat heater switch (LO) Driver's seat heater switch (HI) Rear defogger switch PASSENGER'S MICU Item Front passenger's door switch Right rear door switch Right rear door lock knob switch (UNLOCK) Audio unit Front passenger's seat heater switch (LO) Front passenger's seat heater switch (HI) DOOR MULTIPLEX CONTROL UNIT Item Driver's door lock switch (UNLOCK) Driver's door lock switch (LOCK) Driver's door lock knob switch (UNLOCK) Driver's door lock knob switch (LOCK) Driver's door key cylinder switch (UNLOCK) (1) Driver's door key cylinder switch (LOCK) (1) (1) A second key is necessary to check the key cylinder inputs. Be sure to rotate the key cylinder switch two times to each position (lock and lock, unlock and unlock) to ensure the door lock knob switch is in the appropriate position. FRONT PASSENGER'S POWER WINDOW SWITCH Item Front passenger's door lock switch (UNLOCK) Front passenger's door lock switch (LOCK) Front passenger's door lock knob switch (UNLOCK) POWER SEAT CONTROL UNIT Item Transmission range switch (P) (A/T) Parking brake switch (M/T) Slide switch (Forward) Slide switch (Backward) Recline switch (Forward) Recline switch (Backward) Front UP-DOWN switch (Up) Front UP-DOWN switch (Down) Rear UP-DOWN switch (Up) Rear UP-DOWN switch (Down) Do the front individual map lights and rear individual map lights work properly in all switch positions? YES - Go to function and input test for the system related to the failure. NO - Repair the open, or short, or replace the faulty switch.