Multiplex Integrated Control System Acura TL IV

Scheme 1

Scheme 2

Scheme 3

Troubleshooting CAN Circuit Related Problems

Note. Check the PCM for DTCs and troubleshoot PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first

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 reed the DTCs displayed in the multi-information display (MID) in the gauge assembly, then go to B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - 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 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) )
2. Check for DTCs
3. If there are DTCs stored, sort them, and then troubleshoot the DTCs in this order -1 Battery voltage DTCs -2 Internal error DTCs -3 Loss of communication DTCs NOTE: If DTC U1280 is stored, troubleshoot DTC U1280 first (see «DTC U1280: Communication bus Line Error (BUS-OFF)»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__dtc-u1280-communication-bus-line-error) ) -4 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 «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) )

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, 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 when the communication between the MICU and the gauge control module is normal To scroll through the DTCs, press the SEL/RESET button

Scheme 4

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

CONTROL UNIT SPECIFICATION CHART

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)»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) )
2. While in Test Mode 1, press and hold down the SEL/RESET button for at least 10 seconds to clear the DTCs

Loss of Communication DTC Cross-reference Chart

When an ECU on the CAN circuit is unable to communicate with the other ECUs on the CAN circuit, the other control units will set loss of communication DTCs Use this chart to find the control unit that is not communicating with the other control units on the CAN circuit

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 and Internal Error Codes

BUS OFF AND INTERNAL ERROR CODES CHART

Loss of Communication

LOSS OF COMMUNICATION CHART

DTC Troubleshooting Index

Note. Record all DTCs, and sort them by DTC type using the following DTC troubleshooting indexes, then troubleshoot the DTC(s) in this order

1. Battery voltage DTCs
2. Internal error DTCs
3. Loss of communication DTCs
4. Signal error DTCs

Driver's MICU

DRIVER'S MICU DTC TROUBLESHOOTING INDEX

Passenger's MICU

PASSENGER' MICU DTC TROUBLESHOOTING INDEX

Door Multiplex Control Unit

DOOR MULTIPLEX CONTROL UNIT DTC TROUBLESHOOTING INDEX

Immobilizer-Keyless Control Unit

IMMOBILIZER-KEYLESS CONTROL UNIT DTC TROUBLESHOOTING INDEX

Gauge Control Module

GAUGE CONTROL MODULE DTC TROUBLESHOOTING INDEX

HandsFreeLink Control Unit

HANDSFREELINK CONTROL UNIT DTC TROUBLESHOOTING INDEX

Climate Control Unit

CLIMATE CONTROL UNIT DTC TROUBLESHOOTING INDEX

AcuraLink Control Unit

ACURALINK CONTROL UNIT DTC TROUBLESHOOTING INDEX

Power Seat Control Unit

POWER SEAT CONTROL UNIT DTC TROUBLESHOOTING INDEX

Power Control Unit

POWER CONTROL UNIT DTC TROUBLESHOOTING INDEX

Remote Slot Control Unit

REMOTE SLOT CONTROL UNIT DTC TROUBLESHOOTING INDEX

Keyless Access Control Unit

KEYLESS ACCESS CONTROL UNIT DTC TROUBLESHOOTING INDEX

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 5

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 6

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 7

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 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 its self

Scheme 8

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 to LOCK (0), or the vehicle ignition in 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 the 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 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 is opened or if a key is in the ignition
5. The draw is reduced from 200 mA to less than 35 mA when in the sleep mode

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

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 operate normally

When a CPU problem or a 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 the data is recognized, the MICUs move to the software fail-safe mode The data that cannot be 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 goes below 10 V, the driver's MICU will not store a DTC

INPUT AND OUTPUT CHART

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

The driver's MICU control of the interior light ON/OFF is based on input signals from each switch

INPUT AND OUTPUT CHART

Collision Detection Signal (CDS)

The driver's MICU control of the door lock actuators is based on IG1 and SRS (CDS) signals

INPUT AND OUTPUT CHART

Key Interlock (A/T)

The driver's MICU control of the key interlock solenoid is based on ignition switch ACC (I) position, the transmission range switch P position, and the park-pin switch signals

INPUT AND OUTPUT CHART

Rear Window Defogger Timer Operation

The driver's MICU control of the rear window defogger timer is based on ignition switch and rear window defogger switch signals

INPUT AND OUTPUT CHART

Combination Light Switch

The driver's MICU control of the lighting system is based on input signals from the combination light switch

INPUT AND OUTPUT CHART

Daytime Running Lights

The driver's MICU control of the headlights as daytime running lights is based on input signals from each switch

INPUT AND OUTPUT CHART

Fog Lights

The driver's MICU control of fog lights is based on input signal from the fog light switch

INPUT AND OUTPUT CHART

Headlight Auto-OFF Function*

The driver's MICU control of the lighting system is based on input signals from each switch

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Turn Signal/Hazard Warning Lights

The driver's MICU control of the turn signal/hazard warning lights is based on input signals from the turn signal switch and the hazard warning switch

INPUT AND OUTPUT CHART

Courtesy Light (Driver's side)

The driver's MICU control of the driver's and left rear door courtesy lights is based on input signals from the driver's and left rear door switches

INPUT AND OUTPUT CHART

Wiper

The driver's MICU control of the wiper is based on input signals from each switch

INPUT AND OUTPUT CHART

Driver's Power Window Relay

The driver's MICU control of the power windows is based on input signals from each switch

INPUT AND OUTPUT CHART

Keyless Answer Back*

The driver's MICU control of the lighting system and horns is based on keyless signals sent by the B-CAN

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Security Answer Back*

The driver's MICU control of the lighting system and horns is based on keyless signals sent by the B-CAN

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Answer Back Response Operation

The driver's MICU control of the lighting system and horns is based on keyless signals sent by the B-CAN

INPUT AND OUTPUT CHART

Power Door Locks*

The driver's MICU control of the door lock actuators is based on the input signals from each switch

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Door Lock Response Operation

The driver's MICU control of the door lock actuators LOCK, UNLOCK, DRIVER'S UNLOCK, TRUNK UNLOCK is based on the B-CAN door lock switch signals

INPUT AND OUTPUT CHART

Keyless Entry System*

The driver's MICU control of the door lock actuators is based on the input signals from each switch

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Keyless PANIC Operation

The driver's MICU control of the keyless PANIC operation is based on the B-CAN signals

INPUT AND OUTPUT CHART

Auto Power Door Locks (LOCK operation)*

The driver's MICU control of the door lock actuators is based on input signals from each switch

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Auto Power Door Locks (UNLOCK operation)*

The driver's MICU control of the door lock actuators is based on input signals from each switch

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Security Alarm System

The driver's MICU control of the lighting system and horns is based on input signals from each switch and B-CAN signals

INPUT AND OUTPUT CHART

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

INPUT AND OUTPUT CHART

Courtesy Light (Passenger's side)

The passenger's MICU control of the front passenger and right rear door courtesy lights is based on input signals from the front passenger and right rear door switch

INPUT AND OUTPUT CHART

Power Door Locks (LOCK)*

The passenger's MICU control of the front passenger's side door lock actuators is based on input signals from the driver's MICU

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Power Door Locks (UNLOCK)*

The passenger's MICU control of the front passenger's side door lock actuators is based on input signals from the driver's MICU

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

Exterior Lights

The passenger's MICU control of the front passenger's side headlight, and parking lights is based on input signals from the driver's MICU

INPUT AND OUTPUT CHART

Automatic Lighting*

The passenger's MICU control of the headlights and the parking lights is based on input signals from the automatic lighting sensor

INPUT AND OUTPUT CHART

*The security system can be customized in the multi-information display (MID) to suit the customer's needs. For more information about keyless/security system options, refer to the owner's manual.

The passenger's MICU control of fog lights is based on input signals from the fog light switch

INPUT AND OUTPUT CHART

Washer Operation

The passenger's MICU control of the washer motor is based on input signal from the wiper switch

INPUT AND OUTPUT CHART

Keyless Buzzer Operation

The passenger's MICU control of the keyless buzzer is based on input signal from the answer back signals

INPUT AND OUTPUT CHART

Passenger's Power Window Relay Circuit

The passenger's MICU control of the power window relay circuit in the passenger's under-dash fuse/relay box is based on input signals from the power window signals

INPUT AND OUTPUT CHART

HDS Inputs, Outputs, and Commands

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 software is loaded

DATA LIST

Function Test

FUNCTION CHART

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 do this diagnosis if the symptom is related to the B-CAN system

Scheme 9

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) Chimes (key-in, seat belt, lights-on, and parking brake) Power window/moon roof timer Wiper/washer Security Keyless entry Power door locks Key interlock Dash light brightness Immobilizer Daytime running lights Driving position memory system XM radio AcuraLink HandsFreeLink Climate control Keyless access control 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), or press the engine start/stop button to select the ON mode
3. From the BODY ELECTRICAL menu, select UNIT INFORMATION, and then select CONNECTED UNIT 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 Audio unit Power seat control unit AcuraLink control unit (XM receiver) (HDS name: HIP (Honda Information Platform) Unit) Keyless access control unit (HDS name: Keyless Access ECM) 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 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 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE B»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) ) If all units are not communicating or only the driver's MICU is communicating, go to DTC U1280 troubleshooting (see «DTC U1280: Communication bus Line Error (BUS-OFF)»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__dtc-u1280-communication-bus-line-error) )
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 that is malfunctioning does not stop or turn off, go to B-CAN System Diagnosis Test Mode C (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE C»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) ) 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 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE D»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__troubleshooting-b-can-system-diagnosis-test) ) 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 Chimes (key-in, seat belt, lights-on, and parking brake) Security Keyless entry Key interlock Dash light brightness Audio system Navigation (if equipped) HandsFreeLink Immobilizer Driving position memory system Rear window defogger (climate control) Climate control Keyless access control
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 in 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 menu
2. Select DTCs, and then check for loss of communication DTCs
3. Do the power, ground, and communication part of the input test for the unit(s) not communicating with the HDS

COMMUNICATION CHART

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 control the output devices (see HDS INPUTS, OUTPUTS, AND COMMANDS )

1. Check for DTCs by selecting the TEST MODE menu from the HDS
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
4. In the DATA LIST, check the output signal of the malfunctioning component
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
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 control the output devices (see HDS INPUTS, OUTPUTS, AND COMMANDS )

1. Check the fuse of the malfunctioning output device
2. Check for DTCs by selecting the TEST MODE menu from the HDS
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
5. Check the relay and ground, then check for an open or a short in the circuit for the malfunctioning component
6. Do the function test for the malfunctioning 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
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
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 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 10

1. Check the No 15 (10 A) fuse in the under-hood fuse/relay box and No 12 (7 5 A) fuse in the driver's under-dash fuse/relay box
2. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
3. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and move the ceiling light switch to the middle (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 ceiling light When the ceiling 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 get to the last code, the display shows END If no DTCs are stored, the display will read NO (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system) ) 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 reinsert it to enter Mode 2 When the system enters Mode 2, the ceiling light will flash two times quickly and then go off NOTE: If the MPCS service connector is disconnected for too short or too long, or if the ignition switch is turned to LOCK (0), or if the vehicle is in OFF mode 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 ceiling light will blink once If the circuit is faulty, there will be no indication

Driver's MICU

DRIVER'S MICU ITEM CHART

Passenger's MICU

PASSENGER'S MICU ITEM CHART

Door Multiplex Control Unit

DOOR MULTIPLEX CONTROL UNIT ITEM CHART

Front Passenger's Power Window Switch

FRONT PASSENGER'S POWER WINDOW SWITCH ITEM CHART

Power Seat Control Unit

POWER SEAT CONTROL UNIT ITEM CHART

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, short, or replace the faulty switch

Sleep and Wake-up Mode Test

1. Shift to the sleep mode: Close all doors Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, remove the key without keyless access system, then open and close the driver's door If the MICU receives no signals from the inputs listed below, it will go into sleep mode in less than 50 seconds. IG1 Power supply IG2 Power supply B-CAN data Trunk lid latch switch (Trunk lid closed) (OFF) Hazard warning switch (OFF)
2. Confirm the sleep mode NOTE: Check any official Honda service website for more service information about parasitic draw at the battery Check the parasitic draw at the battery while shifting into the sleep mode, amperage should change from about 200 mA to less than 35 mA in less than 50 seconds
3. Shift to the wake-up mode When the ignition switch is turned to ON (II), or the vehicle is in ON mode The driver's MICU, passenger's MICU, gauge control module, immobilizer-keyless control unit, and PCM will wake-up at the same time without "talking" to each other through the communication lines When any switch in the multiplex integrated control system is turned on, it wakes up its related control unit which, in turn, wakes up the other units After confirming the sleep mode, look in the following table for the switch most related to the problem Operate that switch and see if its control unit wakes up

Note. If any control unit is faulty and will not wake up, several circuits in the system will malfunction at the same time In the table below, it is a list of the switches and input signals that can wake it up

Scheme 11

Scheme 12

Scheme 13

DTC B10A2- Driver's MICU Internal (EEPROM) Error

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC B10A2 indicated?

YES -Faulty driver's MICU, replace the driver's under-dash fuse/relay box (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION )

NO -Intermittent failure, the system is OK at this time

DTC B11A2: Passenger's MICU Internal (EEPROM) Error

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC B11A2 indicated?

YES -Faulty passenger's MICU, replace the passenger's under-dash fuse/relay box (see PASSENGER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION )

NO -Intermittent failure, the system is OK at this time

DTC B1036: Driver's MICU IG1 Line Input Error

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ) Before troubleshooting, check if the No. 12 (7.5 A) fuse in the driver's under-dash fuse/relay box is OK

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS Is DTC B1036 indicated? YES -Go to step 5 NO -Intermittent failure, the system is OK at this time Check for loose or poor connections at the driver's under-dash fuse/relay box connector C (5P) If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iv-2008-2011/remont/body-electrical/#battery) ) and the charging system
5. Measure the voltage between the gauge control module 32P connector terminals No 15 and No 17 and terminals No 1 and No 15 respectively

Scheme 14

Is there battery voltage?

YES -Faulty driver's MICU, substitute a known-good driver's under-dash fuse/relay box and recheck

NO -Check for an open in the BRN wire between the driver's under-dash fuse/relay box and the gauge control module, or check for a poor connection between terminal No 17 and body ground (G401), and/or terminal No 1 and body ground (G402) If the fuse blown, repair a short in the wire between the driver's under-dash fuse/relay box and the gauge control module

DTC B11C7: Passenger's MICU IG1 Line Input Error

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ) Before troubleshooting, check if the No. 12 (7.5 A) fuse in the driver's under-dash fuse/relay box is OK

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS
5. Check the DTCs with the HDS
6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
7. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
8. Measure the voltage between the passenger's under-dash fuse/relay box connector A (38P) terminal No 35 and body ground

Scheme 15

Is there battery voltage?

YES -Faulty passenger's MICU, substitute a known-good passenger's under-dash fuse/relay box and recheck

NO -Check for an open in the BRN wire between the driver's under-dash fuse/relay box and the passenger's under-dash fuse/relay box

DTC U0155: Driver's MICU Lost Communication with Gauge Control Module

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC U0155 indicated?

YES -Go to the gauge control module input test, and do all power, ground, and communication input tests (see GAUGE CONTROL MODULE INPUT TEST ) If the tests prove OK, replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT )

NO -Intermittent failure, the system is OK at this time Check for loose or poor connections at the gauge control module 32P connector and the related units

DTC U0155: Passenger's MICU Lost Communication with Gauge Control Module

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC U0155 indicated?

YES -Go to the gauge control module input test, and do all power, ground, and communication input tests (see GAUGE CONTROL MODULE INPUT TEST ) If the tests prove OK, replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT )

NO -Intermittent failure, the system is OK at this time Check for loose or poor connections at the gauge control module 32P connector and the related units

DTC U0199: Driver's MICU Lost Communication with Door Multiplex Control Unit

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC U0199 indicated?

YES -Go to the door multiplex control unit input test, and do all power, ground, and communication input tests (see POWER WINDOW MASTER SWITCH INPUT TEST ) If the tests prove OK, replace the power window master switch (see POWER WINDOW MASTER SWITCH REPLACEMENT )

NO -Intermittent failure, the system is OK at this time Check for loose or poor connections at the door multiplex control unit 37P connector and the related units

DTC U1280: Communication bus Line Error (BUS-OFF)

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS
5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
6. Disconnect the appropriate connector at each control unit in the table one at a time Clear the DTC, then recheck for DTCs after each unit is disconnected CONTROL UNIT SPECIFICATION CHART Control Unit Connector Passenger's MICU Passenger's under-dash fuse/relay box connector A (38P) Door multiplex control unit 37P connector Gauge control module 32P connector Immobilizer-keyless control unit (1) 7P connector Power control unit (2) Connector C (36P) Keyless access control unit (2) Connector B (32P) Remote slot control unit (2) 40P connector Audio-navigation control unit (4) Connector D (20P) Audio unit (3) Connector D (20P) Climate control unit Connector B (12P) Power seat control unit Connector A (40P) HandsFreeLink control unit 28P connector AcuraLink control unit (5) Connector A (32P) (1) Without keyless access system (2) With keyless access system (3) Without navigation system (4) With navigation system (5) With AcuraLink Is DTC U1280 indicated with each individual unit disconnected? YES -Leave the connectors disconnected, and go to step 7 NO -Go to the input test (or circuit troubleshooting) for the control unit that was disconnected when DTC U1280 did not reset and perform all power and ground input tests If the tests prove OK, replace that unit Passenger's MICU input test (see «MICU INPUT TEST»(/acura/tl/iv-2008-2011/remont/communication-devices/#multiplex-integrated-control-system__micu-input-test) ) Door multiplex control unit input test (see «POWER WINDOW MASTER SWITCH INPUT TEST»(/acura/tl/iv-2008-2011/remont/windows/#power-window-system__power-window-master-switch-input-test) ) Gauge control unit input test (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/tl/iv-2008-2011/remont/gauges-instrument-panels/#display-and-gauge-system__gauge-control-module-input-test) ) Power control unit input test (see «POWER CONTROL UNIT»(/acura/tl/iv-2008-2011/remont/door-locks-anti-theft-systems/#keyless-access-system) ) Keyless access control unit input test (see «CONTROL UNIT INPUT TEST»(/acura/tl/iv-2008-2011/remont/door-locks-anti-theft-systems/#keyless-access-system) ) Remote slot control unit input test (see «REMOTE SLOT CONTROL UNIT»(/acura/tl/iv-2008-2011/remont/door-locks-anti-theft-systems/#keyless-access-system) ) Immobilizer-keyless control unit input test (see «IMMOBILIZER-KEYLESS CONTROL UNIT INPUT TEST»(/acura/tl/iv-2008-2011/remont/door-locks-anti-theft-systems/#immobilizer-system__immobilizer-keyless-control-unit-input-test) ) Climate control unit power and ground circuit troubleshooting (see «CLIMATE CONTROL POWER AND GROUND CIRCUIT TROUBLESHOOTING»(/acura/tl/iv-2008-2011/remont/automatic-hvac-system/#climate-control-system) ) Power seat control unit input test (see «POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT»(/acura/tl/iv-2008-2011/remont/memory-modules/#driver-position-memory-system-dpms__power-seat-control-unit-input-testreplacement) ) HandsFreeLink control unit input test (see «CONTROL UNIT INPUT TEST»(/acura/tl/iv-2008-2011/remont/entertainment-systems/#hands-free-link-system) ) AcuraLink control unit input test (see «ACURALINK CONTROL UNIT (XM RECEIVER) CONNECTOR FOR INPUTS AND OUTPUTS»(/acura/tl/iv-2008-2011/remont/entertainment-systems/#acuralink) ) Audio unit input test (see «AUDIO UNIT CONNECTOR FOR INPUTS AND OUTPUTS»(/acura/tl/iv-2008-2011/remont/entertainment-systems/#audio-system) ) Audio-navigation unit input test (see «NAVIGATION UNIT INPUTS AND OUTPUTS»(/acura/tl/iv-2008-2011/remont/navigation-system/#navigation-system) )
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
8. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
9. Disconnect driver's under-dash fuse/relay box connector P (20P)
10. Check for continuity between driver's under-dash fuse/relay box connector P (20P) terminals No 5 and No 6
11. Check for continuity between body ground and driver's under-dash fuse/relay box connector P (20P) terminals No 5 and No 6 individually
12. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
13. Measure the voltage between body ground and driver's under-dash fuse/relay box connector P (20P) terminals No 5 and No 6 individually

Scheme 16

Is there voltage?

YES -Repair short to power in the wire(s)

NO -Faulty driver's MICU, replace the driver's under-dash fuse/relay box (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION )

DTC U1282. Passenger's MICU Lost Communication with Driver's MICU

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC U1282 indicated?

YES -Go to the driver's MICU input test, and do all power, ground, and communication input tests (see MICU INPUT TEST ) If the tests prove OK, replace the driver's under-dash fuse/relay box (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION )

NO -Intermittent failure, the system is OK at this time Check for loose or poor connections at driver's under-dash fuse/relay box connector P (20P) and the related units

DTC U1283: Driver's MICU Lost Communication with Passenger's MICU

Note. If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

1. Clear the DTCs with the HDS
2. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
3. Wait for at least 6 seconds
4. Check for DTCs with the HDS

Is DTC U1283 indicated?

YES -Go to the passenger's MICU input test, and do all power, ground, and communication input tests (see MICU INPUT TEST ) If the tests prove OK, replace the driver's under-dash fuse/relay box (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION )

NO -Intermittent failure, the system is OK at this time Check for loose or poor connections at driver's under-dash fuse/relay box connector P (20P) and the related units

MICU Input Test

Note. Before testing, troubleshoot the multiplex integrated control system first, using B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

Driver's MICU

Scheme 17

Scheme 18

1. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
2. Remove the driver's dashboard undercover (see «DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#dashboard) )
3. Disconnect driver's under-dash fuse/relay box connectors F, N, P, Q, and R NOTE: All connector views are wire side of female terminals
4. Inspect the connector and socket terminals to be sure they are all making good contact If the terminals are bent, loose or corroded, repair them as necessary and recheck the system If the terminals look OK, go to step 5
5. With the connectors still disconnected, do these input tests at the following connectors If any test indicates a problem, find and correct the cause, then recheck the system If all the input tests prove OK, go to step 6 TEST CONDITION CAVITY CHART Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained P5 (1) BLU Immobilizer-keyless control unit 7P connector disconnected Check for continuity between terminal P5 and immobilizer-keyless control unit 7P connector terminal No 3 There should be continuity An open in the B-CAN wire P6 (1) PNK Check for continuity between terminal P6 and immobilizer-keyless control unit 7P connector terminal No 4 There should be continuity An open in the B-CAN wire P5 (2) BLU Power control unit A (36P) connector disconnected Check for continuity between terminal P5 and power control unit connector A (36P) terminal No 17 There should be continuity An open in the B-CAN wire P6 (2) PNK Check for continuity between terminal P6 and power control unit connector A (36P) terminal No 16 There should be continuity An open in the B-CAN wire P5 (2) BLU Keyless access control unit B (32P) connector disconnected Check for continuity between terminal P5 and keyless access control unit connector B (32P) terminal No 7 There should be continuity An open in the B-CAN wire P6 (2) PNK Check for continuity between terminal P6 and keyless access control unit connector B (32P) terminal No 8 There should be continuity An open in the B-CAN wire P5 (2) BLU Remote slot control unit 40P connector disconnected Check for continuity between terminal P5 and remote slot control unit 40P connector terminal No 23 There should be continuity An open in the B-CAN wire P6 (2) PNK Check for continuity between terminal P6 and remote slot control unit 40P connector terminal No 3 There should be continuity An open in the B-CAN wire P5 BLU Gauge control module 32P connector disconnected Check for continuity between terminal P5 and gauge control module 32P connector terminal No. 25 There should be continuity An open in the B-CAN wire P6 PNK Check for continuity between terminal P5 and gauge control module 32P connector terminal No. 26 There should be continuity An open in the B-CAN wire P5 BLU Door multiplex control unit 37P connector disconnected Check for continuity between terminal P5 and door multiplex control unit 37P connector terminal No. 33 There should be continuity An open in the B-CAN wire P6 PNK Check for continuity between terminal P6 and door multiplex control unit 37P connector terminal No. 35 There should be continuity An open in the B-CAN wire (1) Without keyless access system (2) With keyless access system TEST CONDITION CAVITY CHART Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained P5 BLU Passenger's under-dash Fuse/relay box connector A(38P) disconnected Check for continuity between terminal P5 and passenger's under-dash fuse/relay box connector A (38P) terminal No 29 There should be continuity An open in the B-CAN wire P6 PNK Check for continuity between terminal P6 and passenger's under-dash fuse/relay box connector A (38P) terminal No 11 There should be continuity An open in the B-CAN wire P5 BLU Climate control unit connector C (20P) disconnected Check for continuity between terminal P5 and climate control unit connector B(12P) terminal No 2 There should be continuity An open in the B-CAN wire P6 PNK Check for continuity between terminal P6 and climate control unit connector B (12P) terminal No 1 There should be continuity An open in the B-CAN wire P5 (1) BLU Audio-navigation unit connector D (20P) disconnected Check for continuity between terminal P5 and audio-navigation unit connector D (20P) terminal No 15 There should be continuity An open in the B-CAN wire P6 (1) PNK Check for continuity between terminal P6 and audio-navigation unit connector D (20P) terminal No 6 There should be continuity An open in the B-CAN wire P5 (2) BLU Audio unit connector D (20P) disconnected Check for continuity between terminal P5 and audio unit connector D (20P) terminal No 8 There should be continuity An open in the B-CAN wire P6 (2) PNK Check for continuity between terminal P6 and audio unit connector D (20P) terminal No 18 There should be continuity An open in the B-CAN wire P5 BLU Power seat control unit connector A (40P) disconnected Check for continuity between terminal P5 and power seat control unit connector A (40P) terminal No 39 There should be continuity An open in the B-CAN wire P6 PNK Check for continuity between terminal P6 and power seat control unit connector A (40P) terminal No 40 There should be continuity An open in the B-CAN wire P5 BLU HandsFreeLink control unit 28P connector disconnected Check for continuity between terminal P5 and HandsFreeLink control unit 28P connector terminal No 17 There should be continuity An open in the B-CAN wire P6 PNK Check for continuity between terminal P6 and HandsFreeLink control unit 28P connector terminal No 18 There should be continuity An open in the B-CAN wire P5 (3) BLU AcuraLink control unit connector A (32P) disconnected Check for continuity between terminal P5 and AcuraLink control unit connector A (32P) terminal No 8 There should be continuity An open in the B-CAN wire P6 (3) PNK Check for continuity between terminal P6 and AcuraLink control unit connector A (32P) terminal No 9 There should be continuity An open in the B-CAN wire Q16 LT BLU Under all conditions Check for continuity between terminal Q16 and data link connector 16P connector terminal No 7 There should be continuity An open in the B-CAN wire (1) With navigation system (2) Without navigation system (3) With AcuraLink
6. Reconnect the connectors to the driver's under-dash fuse/relay box, and do these input tests at the following connectors If any test indicates a problem, find and correct the cause, then recheck the system If all the input tests prove OK, go to step 7 NOTE: These are power and ground tests for the driver's MICU TEST CONDITION CAVITY CHART Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained F11 WHT Under all conditions Measure the voltage to ground There should be battery voltage Blown No 15 (10 A) fuse in the under-hood fuse/relay box An open or high resistantce in the wire P9 WHT Under all conditions Measure the voltage to ground There should be battery voltage Blown No 15 (10 A) fuse in the under-hood fuse/relay box Faulty driver's under-dash fuse/relay box An open or high resistance in the wire P20 BRN Ignition switch ON (II), or power mode ON Measure the voltage to ground There should be battery voltage Blown No 12 (7.5 A) fuse in the driver's under-dash fuse/relay box Faulty driver's under-dash fuse/relay box An open or high resistance in the wire N12 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0.2V Poor ground (G402) An open or high resistance in the ground wire Q1 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0.2V Poor ground (G402) An open or high resistance in the ground wire Q2 BRN In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0.2V Poor ground (G401) An open or high resistance in the ground wire R2 BRN In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0.2V Poor ground (G401) An open or high resistance in the ground wire R5 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0.2V Poor ground (G402) An open or high resistance in the ground wire Passenger's MICU
7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and remove the passenger's kick panel (see «TRIM REMOVAL/INSTALLATION - DOOR AREAS»(/acura/tl/iv-2008-2011/remont/exteriorinterior-trim/#interior-trim__trim-removalinstallation-door-areas) )
8. Disconnect passenger's under-dash fuse/relay box connectors A and E NOTE: All connector views are wire side of female terminals
9. Inspect the connector and socket terminals to be sure they are all making good contact If the terminals are bent, loose or corroded, repair them as necessary and recheck the system If the terminals look OK, go to step 10
10. Reconnect the connectors to the passenger's under-dash fuse/relay box, turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and do these input tests at the following connectors If any test indicates a problem, find and correct the cause, then recheck the system If all the input tests prove OK, go to step 11 TEST CONDITION CAVITY CHART Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained A14 WHT Under all conditions Measure the voltage to ground There should be battery voltage Blown No 15 (10 A) fuse in the under-hood fuse/relay box Faulty driver's under-dash fuse/relay box An open in the wire between terminals A14 and P9 in the driver's under-hood fuse/relay box A35 BRN Ignition switch ON (II), or ignition mode ON Measure the voltage to ground There should be battery voltage Blown No 12 (7 5 A) fuse in the driver's under-dash fuse/relay box Faulty driver's under-dash fuse/relay box An open in the wire between terminals A14 and P20 in the driver's under-hood fuse/relay box A36 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V Poor ground (G405) An open or high resistance in the ground wire A37 GRY In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V Poor ground (G401) An open or high resistance in the ground wire E15 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V Poor ground (G201) An open or high resistance in the ground wire E16 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V Poor ground (G203) An open or high resistance in the ground wire
11. If multiple failures are found on more than one control unit, replace the driver's under-dash fuse/relay box (includes the driver's MICU) (see «DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION»(/acura/tl/iv-2008-2011/remont/body-electrical/#under-dash-fuserelay-box) ) If input failures are related to a particular control unit, replace the control unit

See also:
• GENERAL TROUBLESHOOTING INFORMATION
• DTC B10CF: LEFT DAYTIME RUNNING LIGHTS CIRCUIT MALFUNCTION
• DTC TROUBLESHOOTING
• DTC B1275: HEADLIGHT OFF POSITION CIRCUIT MALFUNCTION; DTC B1276: COMBINATION LIGHT SWITCH PARKING (SMALL) POSITION CIRCUIT MALFUNCTION; DTC B1277: HEADLIGHT AUTO POSITION CIRCUIT MALFUNCTION; DTC B1278: HEADLIGHT ON POSITION CIRCUIT MALFUNCTION
• DTC B1279: DIMMER SWITCH CIRCUIT MALFUNCTION
• DTC TROUBLESHOOTING
• DTC B1281: FRONT WIPER MIST POSITION CIRCUIT MALFUNCTION; DTC B1282: FRONT WIPER INT (AUTO) POSITION CIRCUIT MALFUNCTION; DTC B1283: FRONT WIPER LOW POSITION CIRCUIT MALFUNCTION; DTC B1284: FRONT WIPER HIGH POSITION CIRCUIT MALFUNCTION
• DTC B11CF: RIGHT DAYTIME RUNNING LIGHTS CIRCUIT MALFUNCTION
• DTC B1575: AUTO LIGHTING SENSOR MALFUNCTION
• DTC TROUBLESHOOTING
• DTC TROUBLESHOOTING
• DTC B1128: DRIVER'S DOOR LOCK SWITCH SIGNAL MALFUNCTION
• DTC B1129: DRIVER'S DOOR LOCK KNOB MALFUNCTION
• DTC B1130. FRONT PASSENGER'S POWER WINDOW MOTOR A PULSE ERROR; DTC B1131: FRONT PASSENGER'S POWER WINDOW MOTOR B PULSE ERROR
• DTC B1140: DRIVER'S POWER WINDOW POSITION DETECT CIRCUIT MALFUNCTION
• DTC B1142: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH FRONT PASSENGER'S POWER WINDOW SWITCH (UART LINE OPEN)
• DTC B1145: FRONT PASSENGER'S POWER WINDOW POSITION DETECT CIRCUIT MALFUNCTION
• DTC U0155: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH GAUGE CONTROL MODULE
• DTC U0164: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH CLIMATE CONTROL UNIT
• DTC U1282: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH DRIVER'S MICU
• DTC U1283: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH PASSENGER'S MICU
• DTC TROUBLESHOOTING
• DTC U0199: IMMOBILIZER-KEYLESS CONTROL UNIT LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT
• DTC U1282: IMMOBILIZER-KEYLESS CONTROL UNIT LOST COMMUNICATION WITH DRIVER'S MICU
• DTC TROUBLESHOOTING
• DTC B1175: FUEL LEVEL SENSOR (FUEL GAUGE SENDING UNIT) CIRCUIT
• DTC B1176: FUEL LEVEL SENSOR (FUEL GAUGE SENDING UNIT) CIRCUIT SHORT
• DTC U0029: F-CAN COMMUNICATION LINE ERROR
• DTC U0100: GAUGE CONTROL MODULE LOST COMMUNICATION WITH PCM
• DTC U0122: GAUGE CONTROL MODULE LOST COMMUNICATION WITH VSA MODULATOR-CONTROL UNIT (VSA MESSAGE)
• DTC U0127: GAUGE CONTROL MODULE LOST COMMUNICATION WITH THE TPMS CONTROL UNIT (TPMS MESSAGE)
• DTC U0131: GAUGE CONTROL MODULE LOST COMMUNICATION WITH EPS CONTROL UNIT (EPS MESSAGE)
• DTC U0151: GAUGE CONTROL MODULE LOST COMMUNICATION WITH SRS UNIT
• DTC U128B: GAUGE CONTROL MODULE LOST COMMUNICATION WITH POWER CONTROL UNIT
• DTC U1282: GAUGE CONTROL MODULE LOST COMMUNICATION WITH DRIVER'S MICU
• DTC U1283: GAUGE CONTROL MODULE LOST COMMUNICATION WITH PASSENGER'S MICU
• DTC U1286: GAUGE CONTROL MODULE LOST COMMUNICATION WITH KEYLESS ACCESS CONTROL UNIT
• DTC U1289: GAUGE CONTROL MODULE LOST COMMUNICATION WITH REMOTE SLOT CONTROL UNIT
• DTC TROUBLESHOOTING
• DTC B1775: MICROPHONE INPUT/OUTPUT SHORT TO POWER/OPEN (WITHOUT NAVIGATION)
• DTC B1776: MICROPHONE INPUT/OUTPUT SHORT TO GROUND (WITH NAVIGATION)
• DTC B1779: HFL SWITCH OR VOICE CONTROL SWITCH (PICK-UP/HANG-UP BUTTONS) CIRCUIT OPEN/SHORT TO POWER (WITH NAVIGATION)
• DTC B1780: HFL SWITCH (PICK-UP/HANG-UP BUTTONS) CIRCUIT SHORT
• DTC B1792: HANDSFREELINK CONTROL UNIT INTERNAL ERROR
• DTC TROUBLESHOOTING
• DTC B2969: CLIMATE CONTROL UNIT LOST COMMUNICATION WITH DRIVER'S MICU (WIPSW MESSAGE)
• DTC TROUBLESHOOTING
• DTC B2248: HIP POWER SUPPLY ABNORMAL (MORE THAN 16 V)
• DTC TROUBLESHOOTING
• DTC B1825: POWER SEAT SLIDE MOTOR PULSE ERROR
• DTC B1826: POWER SEAT FRONT UP-DOWN MOTOR PULSE ERROR
• DTC B1827: POWER SEAT REAR UP-DOWN MOTOR PULSE ERROR
• DTC B1828: POWER SEAT RECLINE MOTOR PULSE ERROR
• DTC B1829: A/T P SIGNAL AND VSP SIGNAL HAVE AN ILLEGAL COMBINATION
• DTC B1830: LEFT MIRROR POSITION SENSOR MALFUNCTION
• DTC B1832: RIGHT MIRROR POSITION SENSOR MALFUNCTION
• DTC B1836: POWER SEAT POSITION SENSOR CIRCUIT SHORT
• DTC B1837: MEMORY POSITION DELAY
• DTC B1843: UART COMMUNICATION ERROR
• DTC B1844: POWER SEAT SLIDE SWITCH CIRCUIT MALFUNCTION
• DTC B1845: POWER SEAT RECLINE SWITCH CIRCUIT MALFUNCTION
• DTC B1846: POWER SEAT FRONT UP-DOWN SWITCH CIRCUIT MALFUNCTION
• DTC B1847: POWER SEAT REAR UP-DOWN SWITCH CIRCUIT MALFUNCTION
• DTC U0155: LOST COMMUNICATION WITH GAUGE CONTROL MODULE (VSP/NE FRAME)
• DTC U0199: LOST COMMUNICATION WITH P/W (DR LOCK SW FRAME)
• DTC U1282: LOST COMMUNICATION WITH DRIVER'S MICU
• DTC B12A1
• DTC B12C5
• DTC B12C6
• DTC B12C7
• DTC B12D0
• DTC B12E0
• DTC B12F0
• DTC B12F1
• DTC B12F2
• DTC U0155
• DTC U0199
• DTC B1901
• DTC B1926
• DTC B1930
• DTC B1931
• DTC B1601
• DTC U0155
• DTC U0199
• DTC U1282
• DTC U1283
• DTC U0155
• SELF-DIAGNOSTIC FUNCTION
• GAUGE CONTROL MODULE INPUT TEST
• IMMOBILIZER-KEYLESS CONTROL UNIT INPUT TEST
• POWER WINDOW MASTER SWITCH INPUT TEST
• NAVIGATION UNIT INPUTS AND OUTPUTS
• AUDIO UNIT CONNECTOR FOR INPUTS AND OUTPUTS
• POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT
• DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION
• DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION
• BATTERY TEST
• GAUGE CONTROL MODULE REPLACEMENT
• TRIM REMOVAL/INSTALLATION - DOOR AREAS
• TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
• DTC U1280: Communication bus Line Error (BUS-OFF)
• DTC B10A2- Driver's MICU Internal (EEPROM) Error
• DTC B1036: DRIVER'S MICU IG1 LINE INPUT ERROR
• DTC U0155: DRIVER'S MICU LOST COMMUNICATION WITH GAUGE CONTROL MODULE
• DTC U0199: DRIVER'S MICU LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT
• DTC U1283: Driver's MICU Lost Communication with Passenger's MICU
• DTC B11A2: Passenger's MICU Internal (EEPROM) Error
• DTC B11C7: PASSENGER'S MICU IG1 LINE INPUT ERROR
• DTC U1282. PASSENGER'S MICU LOST COMMUNICATION WITH DRIVER'S MICU
• SLEEP AND WAKE-UP MODE TEST
• MICU INPUT TEST
• HDS INPUTS, OUTPUTS, AND COMMANDS
• GENERAL TROUBLESHOOTING INFORMATION