Multiplex Integrated Control System: Other Acura RDX I facelift

Using the HDS (Preferred method)

1. Connect the HDS to the DLC.
2. There are two ways to read the B-CAN code with the HDS. First method; If multiple DTCs are stored, be sure to follow the instructions in the B-CAN system diagnosis, Test Mode A (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-513878-S27009606942012111600000) ). Second method; If no DTCs are retrieved, use the B-CAN System Diagnostic Test Mode 2 (see step 10 ), to check all inputs related to the failure.

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

Enter B-CAN System Diagnosis Test Mode 1 (see ). While in Test Mode 1, when communication between the MICU and the gauge control module is normal, 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 9

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

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 and from F-CAN to B-CAN. This is called the Gate Way Function.

Scheme 10

1. The single wire method is used between the units not requiring the communication to move at a fast speed.
2. Using a single wire method reduces the number of the wires used on the body controller area network.

Gateway Function

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

Scheme 11

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 self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).

Scheme 12

Self-Diagnostic Function

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 the K-LINE. The K-LINE is a separate communication line from the CAN line, but it is connected to most of 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 performing 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 itself.

Scheme 13

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 turned to LOCK (0).

1. In the sleep mode, the MICU 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 unit in the sleep mode immediately wakes up and begins to function.
3. When the ignition switch is turned to LOCK (0) with all the doors and the tailgate closed, and the driver's door is opened, then closed, there is a delay 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 and tailgate are opened or if a key is in the ignition.

Note. Sleep and Wake-Up Mode Test (see SLEEP AND WAKE-UP MODE TEST ).

Fail-Safe Function

To prevent improper operation, the MICU 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 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.

Hardware Fail-Safe Control

Fail-safe function

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 the data is recognized, the MICU moves to the software fail-safe mode. The data that cannot be received is compulsory fixed to a pre-programmed value.

Power Supply Voltage Monitoring Function

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

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

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

Lighting System (Headlights, Parking Lights, Side Marker Lights, Fog Lights, License Plate Lights, and Taillights)*

The MICU contains the relay circuits of the headlight high/low beams and taillights, and controls the lighting system ON/OFF based on inputs from the combination light switch.

Daytime Running Lights

The MICU controls the exterior lights and daytime running lights based on inputs from each switch.

Automatic Lighting System

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

Turn Signal/Hazard Warning Lights

The MICU controls the turn signal/hazard warning lights based on inputs from the turn signal and hazard warning switches.

Power Door Locks (Vehicle Speed Sensor)*

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

Keyless Entry System*

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

Keyless PANIC

The MICU controls the keyless PANIC operation based on keyless signals sent by B-CAN data.

Security Alarm System*

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

Key Interlock

The MICU controls the key interlock solenoid based on IG1, the transmission range switch, and the park-pin switch signals.

Windshield Wiper/Washer

The MICU controls the windshield wiper motor and the washer motor based on IG1, the wiper/washer switch, and the windshield wiper motor.

Rear Window Wiper/Washer

The MICU controls the rear window wiper motor and the washer motor based on IG1, the wiper/washer switch, and the rear window wiper motor.

Collision Detection Signal (CDS)

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

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

Scheme 14

1. Compare the symptom with this list of B-CAN related systems: Gauge control module Exterior lights Turn signals Entry light control Interior lights Door-open and tailgate-open 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 Dashlight brightness Immobilizer AcuraLink® 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).
3. From the BODY ELECTRICAL menu, select B-CAN CONTROL UNITS INFORMATION, and then select the CONNECTED UNITS listed to see if the following control units are communicating with the HDS. MICU Gauge control module Immobilizer-keyless control unit Automatic lighting control unit Climate control unit Power seat control unit (HDS name: Memory seat control unit) HandsFreeLink control unit AcuraLink® control unit (XM receiver) (HDS name: HIP (Honda Information Platform) unit) (USA models with navigation) 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 connected units 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 units are not communicating, go to B-CAN System Diagnosis Test Mode B (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE B»(ref-513878-S22608256872012111600000) ). If all units are not communicating or only the MICU is communicating, go to DTC B1000 troubleshooting (see «DTC B1000: COMMUNICATION CIRCUIT ERROR (BUS-OFF)»(ref-513878-S33467679332012111600000) ).
4. Select the system that has the problem from the BODY ELECTRICAL 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 does not stop or turn off, go to B-CAN System Diagnosis Test Mode C (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE C»(ref-513878-S23336638602012111600000) ). If the problem is related to one of the following items and the system does not work or turn on, go to B-CAN System Diagnosis Test Mode D (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE D»(ref-513878-S10263750542012111600000) ). Exterior lights Turn signals Entry light control Interior lights Horn (security and panic) Wiper/washer If the problem is related to one of the following items, go to troubleshooting for that individual system. Gauge control module Door-open and tailgate-open indicators Beepers (key-in, seat belt, lights-on, and parking brake) Security Keyless entry Key interlock Dashlights brightness Navigation (if equipped)
5. Record all DTCs, and troubleshoot them in this order: Battery voltage DTCs. Internal error DTCs. Loss of communication DTCs. Begin troubleshooting with the lowest number first (Example: if DTC B1008 and B1011 are retrieved, begin by troubleshooting B1008). Signal error DTCs.

Troubleshooting - B-CAN System Diagnosis Test Mode B

Perform this diagnosis if any of the control units are not communicating (Not Available is displayed on the HDS) as found by 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 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 -Faulty MICU; replace the under-dash fuse/relay box (see «REMOVAL AND INSTALLATION»(ref-513873-S08992568522012111600000) ).
3. Do the power, ground, and communication part of the input test for the units not communicating with the HDS.

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 TROUBLESHOOTING - 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 controls 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 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-513878-S27009606942012111600000) ). 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 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 TROUBLESHOOTING - 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 controls 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 blown 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 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-513878-S27009606942012111600000) ). 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 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 indicated 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. Are 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 PCM for DTCs and troubleshoot PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first, then do this diagnosis if the HDS is not available.

Scheme 15

1. Check the No. 23 (10 A) fuse in the under-hood fuse/relay box and No. 10 (7.5 A) fuse in the 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 «CENTER PANEL REMOVAL/INSTALLATION»(ref-513880-S11215136062012111600000) ).
3. Turn the ignition switch to ON (II), and move the interior lights switch to the DOOR position, and the ceiling light switch to the middle (door) position.
4. Connect the MPCS (MCIC) 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, ceiling light, and ignition key light. When the individual map lights, ceiling light, and ignition key light flashes 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 belt 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-513878-S38485174142012111600000) ). NOTE: If the test time out, remove the MPCS (MCIC) 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 sort them into these categories: Battery voltage DTCs Internal error DTCs Loss of communication DTCs (begin with the lowest number first; for example, if B1008 and B1011 are retrieved, troubleshoot B1008 first) 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 (MCIC) service connector from the under-dash fuse/relay box MICU service check connector socket for 5 - 10 seconds, then re-insert it to enter Test Mode 2. When the system enters Test Mode 2, the individual map lights, ceiling light, 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 if the ignition switch is turned to LOCK (0), the system will return 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 individual map lights, ceiling light, and ignition key light blink once. If the circuit is faulty, there is no indication. MICU 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) Front passenger's door lock switch (UNLOCK) Front passenger's door lock switch (LOCK) Front passenger's door lock knob switch (UNLOCK) Left rear door lock knob switch (UNLOCK) Right rear door lock knob switch (UNLOCK) Driver's door switch (OPEN) Front passenger's door switch (OPEN) Left rear door switch (OPEN) Right rear door switch (OPEN) Trunk lid/Tailgate switch (OPEN) Trunk lid/Tailgate handle switch (OPEN) Audio switch Windshield wiper HI/LO switch Windshield wiper INT/LO switch Windshield wiper MIST switch Windshield washer switch (ON) Windshield wiper intermittent dwell time controller Turn signal switch (LEFT) Turn signal switch (RIGHT) Hazard warning switch (ON) Headlight switch (ON) Headlight switch (OFF) Lighting switch (ON) Dimmer switch (ON) Passing switch (ON) Security hood switch (OPEN) Transmission range switch (P) Brake switch (ON) Fog light switch Ignition key cylinder switch Windshield wiper motor park switch Rear washer switch Rear wiper motor park switch Rear wiper switch (ON) Transmission range switch (R) A/C pressure switch/thermal protector (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. Does the ceiling light 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.