Multiplex Integrated Control System: Other Acura MDX II 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

Using the B-CAN System Diagnosis Test Mode 1 (Use only if the HDS is unavailable)

1. Check for communication circuit problems using «B-CAN System Diagnostic Test Mode 1»(ref-510485-S12032953112012102300000) .
2. Check for DTCs.
3. If there are DTCs stored, sort them, and then troubleshoot the DTCs in this order. Battery voltage DTCs Internal error DTCs Loss of communication DTCs NOTE: If DTC B1000 is stored, troubleshoot «DTC B1000»(ref-510485-S42235408772012102300000) first Signal error DTCs
4. If no DTCs are retrieved, use «B-CAN System Diagnostic Test Mode 2»(ref-510485-S12032953112012102300000) to check all inputs related to the failure

How to display DTCs on the gauge control module

Enter B-CAN System Diagnosis Test Mode 1 . 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 multi-information display (MID) when communication between the MICU and the gauge control module is normal. To scroll through the DTCs, press the SEL/RESET button.

Scheme 13

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

How to clear DTCs

1. Enter «B-CAN System Diagnosis Test Mode 1»(ref-510485-S12032953112012102300000)
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 (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 and relays the information from B-CAN to F-CAN A and from F-CAN A to B-CAN. This is called the Gateway function.

Scheme 14

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 A, and from F-CAN A to B-CAN.

Scheme 15

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 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 in LOCK (0).

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) with all the doors and the hatch closed, and the driver's door is opened, then closed, there is a delay of about 40 seconds before the control unit goes from the wake-up mode to the sleep mode.
4. The sleep mode will not function if any door or the hatch is open, or if a key is in the ignition switch.

Note. Sleep and Wake-up Mode Test .

Fail-safe Function

To prevent improper operation, the MICU has a fail-safe function. In 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 operate normally.

When a CPU problem or an abnormal power supply voltage is detected, the MICU moves 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 MICU moves 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 MICU monitors the power supply voltage (back-up voltage). If the voltage goes below 10 V, the MICU does not store a DTC.

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

The MICU controls the interior lights and ignition key light ON/OFF based on inputs from each switch.

Back-up Lights

The MICU controls the back-up lights based on inputs from each switch.

Turn Signal/Hazard Warning Lights

The MICU controls the turn signal/hazard warning lights based on inputs from each switch.

Collision Detection Signal (CDS)

The MICU controls the door lock actuators based on inputs from SRS signals sent by B-CAN.

Automatic Lighting System*

The MICU controls the automatic lighting system based on inputs from each switch.

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

Key Interlock

The MICU controls the key interlock solenoid based on inputs from each switch.

Power Door Locks (Unlock all doors and tailgate at the same time)*

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

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

Power Door Locks (Unlock only the driver's door first)*

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

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

Keyless Entry System (Unlock all doors and tailgate at the same time)41

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

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

Keyless Entry System (Unlock only the driver's door first)*

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

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

Security Alarm System

The MICU controls the lighting system and the horn based on inputs from each switch.

Prevention of Key Locked Inside Vehicle

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

Interior Lights Reminder

The MICU controls the interior lights OFF based on inputs from each switch.

Tailgate Lights

The rear MICU controls the tailgate lights based on inputs from each switch.

Rear Door Courtesy Lights

The rear MICU controls the rear door courtesy lights based on inputs from each switch.

Exterior Lights

The relay control module controls the exterior lights based on inputs from the combination light switch signals.

Daytime Running Lights

The relay control module controls the daytime running lights based on inputs from each switch.

The relay control module controls the automatic lighting based on inputs from each switch.

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

Interior Illuminations*

The relay control module controls the interior illuminations based on inputs from the interior light relay signals.

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

Exterior Lights Shutoff System*

The relay control module controls the exterior lights shutoff based on inputs from each switch.

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

Fog lights

The relay control module controls the fog lights based on inputs from the combination light switch signals.

Windshield Wiper (Vehicle Speed Sense)*

The relay control module controls the windshield wiper (vehicle speed sense) based on inputs from each switch.

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

Rear Window Washer

The relay control module controls the rear window washer based on inputs from the window washer switch.

The relay control module controls the security system and the horn based on inputs from the security hood switch.

Security Answer Back*

The relay control module controls the exterior lights and the horn based on inputs from the answer back signals.

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

Keyless Panic Function

The relay control module controls the keyless PANIC function based on inputs from the PANIC signals.

Headlight Washer

The relay control module controls the headlight washer based on inputs from each switch.

HDS Inputs and Commands

Certain inputs happen so quickly that the HDS can not 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 for newer vehicles, it is not uncommon to see system function tests that are not supported.

Make sure that the most current software is loaded.

Input

Function Test

Troubleshooting - B-CAN System Diagnosis Test Mode A

Check the PCM for DTCs and troubleshooting 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 Rear window defogger HandsFreeLink Horns (security and panic) Beepers (key-in, seat belt, lights-on, low battery voltage, and parking brake) Power windows Power window/moonroof timer Wiper/washer Security Keyless entry Power door locks Climate control Key interlock Dashlights brightness Driving position memory system Power tailgate XM radio AcuraLink Immobilizer 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 (A), then turn the ignition switch to ON (II).
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. MICU Gauge control module Combination switch control unit Relay control module Power seat control unit (HDS name: Memory seat control unit) HandsFreeLink control unit Driver's MPCS unit Rear MICU AcuraLink control unit (XM receiver) (HDS name: HIP (Honda Information Platform) Unit) Power tailgate control unit Climate control unit Immobilizer-keyless control unit BSI control unit NOTE: If a unit is communicating with the HDS, DETECT will be displayed. If a unit is not communicating or the vehicle is not equipped, "Not Available" will be displayed. The HDS only checks the connected units status one time when BODY ELECTRICAL is selected. To recheck the status after repair, reboot the HDS and repeat step 3 . Are all control units communicating with the HDS? YES -Go to step 4. NO -If any of the control unit are not communicating, go to «B-CAN System Diagnosis Test Mode B»(ref-510485-S03306819582012102300000) . If all units are not communicating or only the MICU is communicating, go to the «DTC B1000 troubleshooting»(ref-510485-S42235408772012102300000) .
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-510485-S38546623202012102300000) , if the problem is related to one of the following items and the system that is malfunctioning does not work or turn on, go to «B-CAN System Diagnosis Test Mode D»(ref-510485-S25988970962012102300000) Exterior lights Turn signals Entry light control Interior lights Horns (security and panic) Power windows Wiper/washer 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, low battery voltage, and parking brake) Rear window defogger (climate control) Security Keyless entry Climate control Key interlock Dashlights brightness Navigation Driving position memory system HandsFreeLink Power tailgate Immobilizer BSI system
5. Record all DTCs, and troubleshoot them 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 in the HDS) as found by the 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 DTCs, and then check for loss of communication DTCs. Are any loss of communication DTCs indicated? YES -Go to step 3. NO -Replace the MICU.
3. Do the power, ground, and communication part of the input test for the unit(s) not communicating with the HDS. NOTE: Troubleshoot Rear MICU loss of communication DTCs before troubleshooting AcuraLink control unit (XM receiver), the power tailgate control unit, and the power seat control unit DTC. Unit not communicating «MICU»(ref-510485-S29653155802012102300000) Gauge control module (see «GAUGE CONTROL MODULE INPUT TEST»(ref-510457-S35543565072012102300000) ) «Relay control module»(ref-510485-S26146196282012102300000) Driver's MPCS unit «DRIVER'S MPCS UNIT INPUT TEST»(ref-510499-S08887728232012102300000) ) Combination switch control unit «WIPER/WASHER SWITCH (COMBINATION SWITCH CONTROL UNIT) INPUT TEST»(ref-510503-S19702323962012102300000) ) Immobilizer-keyless control unit «IMMOBILIZER-KEYLESS CONTROL UNIT INPUT TEST»(ref-510455-S33368856502012102300000) ) «Rear MICU»(ref-510485-S11569436802012102300000) Power seat control unit «POWER SEAT CONTROL UNIT INPUT TEST»(ref-510495-S10910314782012102300000) ) Power tailgate control unit «CONTROL UNIT INPUT TEST/REPLACEMENT»(ref-510519-S07978360052012102300000) ) Climate control unit «CLIMATE CONTROL UNIT POWER AND GROUND CIRCUIT TROUBLESHOOTING»(ref-510445-S30393011852012102300000) ) BSI control unit «BLIND SPOT INFORMATION SYSTEM (BSI) CONTROL UNIT INPUTS AND OUTPUTS»(ref-510489-S29344964282012102300000) ) HandsFreeLink control unit «CONTROL UNIT INPUT TEST»(ref-510510-S31302287622012102300000) ) AcuraLink control unit «ACURALINK CONTROL UNIT (XM RECEIVER) CONNECTOR FOR INPUTS AND OUTPUTS»(ref-510522-S31945572832012102300000) )

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 run or 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

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-510485-S14009882562012102300000) 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. Test the relay that controls the device that does not stop or turn off, if applicable. If the relay tests OK, 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. Test 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 work 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

1. Check the fuse of the malfunctioning output device. Is the fuse OK? YES -Go to step 2. NO -Replace the fuse, and recheck.
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-510485-S14009882562012102300000) 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. Test the relay and ground that controls the device that does not work, if applicable. If the relay and ground test OK, 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 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 input and the ground 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 12V)? 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 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. Test 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 (MCIS) Service Connector 07WAZ-001010A

Test Mode 1

Check the PCM for DTCs and troubleshoot PCM 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. 7 (10 A) and the No. 21 (7.5 A) fuses in the under-dash fuse/relay box. Are the fuses OK? YES -Go to step 2. NO -Find and repair the cause of the blown fuse.
2. Remove the left kick panel «TRIM REMOVAL/INSTALLATION - DOOR AREAS»(ref-510486-S36301704662012102300000) ).
3. Turn the ignition switch to ON (II), and press the interior light control button (DOOR).
4. Connect the MPCS service connector (A) to the MICU service check connector socket (B) in the under-dash fuse/relay box.
5. Wait 5 seconds, and watch the individual map lights and ignition key light When they flash once quickly and then go 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. 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 11 .
7. Record all DTCs and sort them into these categories: Battery voltage DTCs Internal error DTCs Loss of communication DTCs Signal error DTCs
8. Troubleshoot the DTCs in the order listed above.
9. Clear the DTCs by pressing and holding the SEL/RESET button for at least 10 seconds.
10. You will hear a beep to confirm the codes have been cleared. Operate the devices that failed, and recheck for codes. Test Mode 2
11. Remove the MPCS service connector from the 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 individual map lights and ignition key light flash two times quickly and then go off. NOTE: If the MPCS service connector is disconnected for too short or too long of a time, or the ignition switch is turned to LOCK (0), the system returns to Test Mode 1. MICU Item Driver's door switch (ON; door opened) Front passenger's door switch (ON; door opened) Left rear door switch (ON; door opened) Right rear door switch (ON; door opened) Automatic lighting sensor Headlight washer switch (ON; switch pressed) Ignition key switch (ON; key inserted) Brake pedal position switch (ON; pedal pressed) Transmission range switch (P, R) Audio security ground (when connected) Power mirror selector switch (LEFT, RIGHT) Power mirror adjustment switch (LEFT, RIGHT, UP, DOWN) RELAY CONTROL MODULE Item Windshield wiper switch (AUTO STOP/PARK) Security hood switch (ON; hood opened) COMBINATION SWITCH CONTROL UNIT Item Turn signal switch (LEFT) Turn signal switch (RIGHT) Combination light switch (ON; each position) Dimmer switch (ON) Passing switch (ON) Windshield wiper switch (ON) Intermittent wiper dwell timer Windshield washer switch (ON) Fog light switch (ON) Rear window wiper switch (ON) Rear window washer switch (ON) REAR MICU Item Full latch switch (Built into the tailgate closer unit) (ON) DRIVER'S MPCS UNIT Item Power window master switch (Driver's window UP) Power window master switch (Driver's window DOWN) Power window master switch (Driver's window AUTO UP) Power window master switch (Driver's window AUTO DOWN) Power window master switch (Front passenger's window UP) Power window master switch (Front passenger's window DOWN) Power window master switch (Front passenger's window AUTO UP) Power window master switch (Front passenger's window AUTO DOWN) Power window master switch (Left rear window UP) Power window master switch (Left rear window DOWN) Power window master switch (Right rear window UP) Power window master switch (Right rear window DOWN) Driver's door key cylinder switch (1) (LOCK) Driver's door key cylinder switch (1) (UNLOCK) Driver's door lock switch (LOCK) Driver's door lock switch (UNLOCK) Driver's door lock knob switch (LOCK) Driving position memory switches (1, 2, memo) Left rear power window switch (UP) Left rear power window switch (DOWN) Fuel fill door opener switch (ON) (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. GAUGE CONTROL MODULE Item Parking brake switch (ON; parking brake applied) Distance switch (ON; switch pressed) VSA OFF switch (ON; switch pressed) CMBS OFF switch (ON; switch pressed) Active damper system switch (ON; switch pressed) Cruise control main SET/RESUME/CANCEL switch (ON; switch pressed) Transmission range switch (P, R, N, D, S) Dashlights brightness controller (+, -) Multi - information switch (SEL/RESET, PREVIOUS, NEXT) POWER SEAT CONTROL UNIT Item Transmission range switch (P) Power seat slide switch (FORWARD, BACKWARD) Power seat front up-down switch (UP, DOWN) Power seat rear up-down switch (UP, DOWN) Power seat recline switch (FORWARD, RECLINE) Power tilt/telescopic steering switch (UP, DOWN, PUSH, PULL) FRONT PASSENGER'S MPCS UNIT Item Front passenger's door lock switch (LOCK) Front passenger's door lock switch (UNLOCK) Front passenger's power window switch (UP, DOWN, AUTO) Right rear power window switch (UP, DOWN) Do the individual map lights and ignition key light indicate proper switch operation? YES -Go to function and input test for the system related to the failure. NO -Repair an open, a short, or replace the faulty switch.