Multiplex Integrated Control System: Other Acura RL II facelift

Using the HDS (Preferred method)

1. Go to «B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-348551-S28830677002009112400000) to check for "Connected units" and DTCs (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-348551-S28830677002009112400000) ).
2. If no DTCs are retrieved, go to B-CAN System Diagnosis Test Mode C (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE C»(ref-348551-S15444083792009112400000) ) or D (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE D»(ref-348551-S39144024862009112400000) ).

Without HDS (Use only if the HDS is unavailable)

1. Check for communication circuit problems using B-CAN System Diagnostic Test Mode A (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(ref-348551-S28830677002009112400000) ).
2. Check for DTCs.
3. Sort, and then troubleshoot the DTCs in this order: Battery voltage DTCs Internal error DTCs Loss of communication DTCs (beginning with the lowest number first; for example, if DTC B1005 and B1008 are retrieved, troubleshoot B1005 first). Refer to loss of communication cross reference chart. Signal error DTCs
4. If no DTCs are retrieved, use B-CAN System Diagnostic Test Mode 2 to check all inputs related to the failure (see step 11 on ).

Scheme 13

1. Turn the ignition switch to ON (II).
2. Connect the MPCS service connector to the MCIC socket in the driver's under-dash fuse/relay box.
3. Wait 5 seconds, then watch the multi-information display (MID). While in Test Mode 1, the DTCs that 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 when the communication between the multiplex integrated control unit (MICU) and the gauge control module is normal. To scroll through the DTCs, press the select/reset button on the steering wheel. The unit that has stored the code can be identified by the number shown on the multi-information display (MID). ITEM SPECIFICATION UNIT Code (Control Unit I.D. Number) MICU 10 Relay control module 11 Driver's MPCS unit 30 Gauge control module 50 Climate control unit 51 Combination switch control unit 70 Adaptive front lighting control unit 73 Keyless access control unit 90 HandsFreeLink control unit 94 Power seat control unit 95 AcuraLink control unit (XM receiver) 97

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

The fast controller area network (F-CAN) and the body controller area network (B-CAN) share information between multiple electronic control units (ECUs). B-CAN communication moves at a slower speed for convenience related items and for other functions. F-CAN information moves at a faster speed for "real time" functions such as fuel and emissions data. To allow both systems to share information, the gauge control module translates information from the B-CAN to the F-CAN and from the F-CAN to the B-CAN.

The ECUs on the B-CAN and the F-CAN transmit and receive information in the form of structured messages that may be received by several different ECUs on the network at one time. These messages are transmitted and received across a communication circuit that consists of a single wire that is shared by all the ECUs on the circuit. Since messages on the F-CAN are typically of higher importance, a second wire is used for communication circuit integrity monitoring. A backup circuit is also added to the headlight and wiper circuits on the B-CAN in the event of a network wire or ECU failure that would effect the operation of the system.

Scheme 14

Messages are transmitted by an ECU (that monitors an input) over the communication circuit. ECUs that use the message (information related to that input) are the receivers. For example, the combination switch control unit monitors the wiper switch. When the wiper switch is placed in the low speed position, the combination switch control unit transmits that message on the communication circuit. The relay control module receives the message and turns on the wipers by providing a ground for the relay.

Scheme 15

Connected ECUs

Several ECUs are connected to each of the two networks. The gauge control module is part of both networks since it is the "gateway" between them. Here is a list of ECUs and the network they are connected to.

B-CAN ECUs

1. Gauge control module
2. Relay control module
3. MICU
4. Driver's MPCS unit
5. Combination switch control unit
6. Climate control unit
7. HandsFreeLink control unit
8. Power seat control unit
9. Adaptive front lighting control unit
10. Keyless access control unit
11. AcuraLink control unit (XM receiver)

F-CAN ECUs

Scheme 16

1. Gauge control module
2. PCM
3. VSA modulator-control unit
4. TPMS control unit
5. SH-AWD control unit
6. Adaptive cruise control unit
7. E-pretensioner unit
8. Data link connector

Network "Loss of Communication" Error Checking

The B-CAN and the F-CAN send messages to each other to check the integrity of the network communication circuit. They do this by sending a specific digital message out after an event. For example, after turning the ignition switch to ON (II), all the ECUs on the communication circuit expect to receive a message from other specific units within a specified amount of time. If the message is not received, the ECU will transmit a DTC reporting that it did not receive the message.

Scheme 17

1. Turn the ignition switch to ON (II).
2. The driver's MPCS unit transmits a door lock switch message.
3. The MICU, relay control module, gauge control module, and keyless access control unit receive the door lock switch message.
4. The communication circuit test is passed. Since the door lock switch message was received by all the ECUs expecting to receive a message, the communication circuit between those units is OK. There are multiple messages sent and received by each ECU during this time to insure that the communication circuit is intact. Failed circuit
5. Turn the ignition switch to ON (II).
6. The driver's MPCS unit transmits a door lock switch message.
7. The MICU, relay control module, gauge control module, and keyless access control unit expect to receive the door lock switch message, but since there is a break in the communication circuits, it is not received.
8. Each ECU that expects to receive the door lock switch message from the driver's MPCS unit will transmit DTCs for the message that it did not receive. Since there is a break in the communication circuit, the door lock switch message could not be received by the MICU, the relay control module, the gauge control module, or the keyless access control unit. Each of these units will set "loss of communication" error codes for the message(s) they did not receive. There may be multiple communication DTCs if the unit that has become disconnected from the network would normally transmit multiple messages during the communication line test. For example, the driver's MPCS unit sends the door switch message and door lock switch message during the communication circuit test.

B-CAN System Unit Input/Output Index

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

INPUT AND OUTPUT SIGNAL CHART

DATA LIST REFERENCE

HDS Inputs, Outputs, and Commands

DATA LIST REFERENCE

Outputs

DATA LIST REFERENCE

Troubleshooting - B-CAN System Diagnosis Test Mode A

Note. AcuraLink can be used to easily check for B-CAN line failure (see SELF-DIAGNOSTIC FUNCTION ).

Do this diagnosis first if the symptom is related to the B-CAN system.

Note. Always turn the ignition switch within 3 seconds when prompted in the DTC troubleshooting procedures in this section.

1. Check the symptom against 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) Chimes (key, seat belt, lights-on, and parking brake) Power windows Power window/moonroof timer Wiper/washer Security Keyless entry Power door locks Climate control Key interlock Dash light brightness Driving position memory system Keyless access XM radio 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, then turn the ignition switch to ON (II).
3. From the BODY ELECTRICAL SYSTEM SELECT menu, select UNIT INFORMATION, and then select CONNECTED UNIT listed to see if it is communicating with the HDS. MICU Gauge control module Combination switch control unit Relay control module Power seat control unit HandsFreeLink control unit Driver's MPCS unit Adaptive front lighting control unit AcuraLink control unit (XM receiver) Keyless access control unit Climate control unit NOTE: If the unit is communicating with the HDS, DETECT will be displayed. If the unit is not communicating, "Not Available" will be 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 them are not communicating, go to B-CAN System Diagnosis Test Mode B (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE B»(ref-348551-S11155178272009112400000) ). If all units are not communicating or only the MICU is communicating, go to «DTC B1000»(ref-348551-S36268607312009112400000) troubleshooting (see «DTC TROUBLESHOOTING»(ref-348551-S42467243852009112400000) ).
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, go to B-CAN System Diagnosis Test Mode C (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE C»(ref-348551-S15444083792009112400000) ). 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 Chimes (key, seat belt and lights-on) Rear window defogger (climate control) Security Keyless entry Climate control Key interlock Dash light brightness Audio system Navigation Driving position memory system HandsFreeLink Keyless access Adaptive front lighting
5. Record all DTCs, and sort them by DTC type using the DTC Troubleshooting.
6. Troubleshoot the DTC(s) in this order: Battery voltage DTCs. Internal error DTCs. Loss of communication DTCs. Begin troubleshooting with the lowest number first (Example: if DTC B1005 and B1008 are retrieved, begin by troubleshooting B1005). 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 (use the DTC Troubleshooting to find the DTC type). Are any loss of communication DTCs indicated? YES -Go to step 3. NO -Replace the MICU.
3. Perform the input test or circuit troubleshooting for the unit not communicating with the HDS.

MICU INPUT TEST REFERENCE

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 B-CAN SYSTEM UNIT INPUT/OUTPUT INDEX ). Always turn the ignition switch within 3 seconds when prompted in the DTC troubleshooting procedures in this section.

1. Check for DTCs by selecting the TEST 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-348551-S28830677002009112400000) ). NO -Go to step 2.
2. Turn OFF the switch that controls the malfunctioning component.
3. Select DATA LIST from the TEST MODE MENU, 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 (see «B-CAN SYSTEM UNIT INPUT/OUTPUT INDEX»(ref-348551-S36412995382009112400000) ).
5. Check the relay if applicable, then check for a short in the wire between the relay and the component, 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 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. Is the switch and wire harness OK? YES -Replace the control unit that monitors the switch. NO -Replace the switch or repair 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 B-CAN SYSTEM UNIT INPUT/OUTPUT INDEX ). Always turn the ignition switch within 3 seconds when prompted in the DTC troubleshooting procedures in this section.

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 TEST 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-348551-S28830677002009112400000) ). NO -Go to step 3.
3. Turn ON the switch that controls the malfunctioning component.
4. Select DATA LIST from the TEST MODE MENU, 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 MISC. TEST from the TEST 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 TEST 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. Is the switch and the wire harness OK? YES -Replace the control unit that monitors the switch. NO -Replace the switch or repair the wire harness.

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

Special Tools Required

MPCS service connector 07WAZ-001010A