Multiplex Intergrated Control System Acura TL III

Scheme 1

Scheme 2

Scheme 3

Troubleshooting CAN Circuit Related Problems

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

Using the HDS (Preferred method)

1. Go to B-CAN System Diagnosis Test Mode A to check for "Connected units" and DTCs (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__troubleshooting-b-can-system-diagnosis-test) ).
2. If no DTCs are retrieved, go to B-CAN System Diagnosis Test Mode C (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE C»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__troubleshooting-b-can-system-diagnosis-test) ) or D (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE D»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__troubleshooting-b-can-system-diagnosis-test) ).

Without HDS (Use Only If The HDS Is Unavailable)

1. Check for communication circuit problems using 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/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) ).
2. Check for DTCs while in Mode 1 (see «GAUGE CONTROL MODULE DTC DISPLAY»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__gauge-control-module-dtc-display) ). NOTE: If the problem is related to the display panel control unit or Hands Free Link system, check for DTCs first with their own self-diagnostic function. HandsFreeLink control unit self-diagnostic function (see «SELF-DIAGNOSTIC FUNCTION»(/acura/tl/iii-2003-2006/remont/communication-devices/#handsfree-link-system__self-diagnostic-function) ). Display panel control unit self-diagnostic function (see «SELF-DIAGNOSTIC FUNCTION»(/acura/tl/iii-2003-2006/remont/gauges-instrument-panels/#display-panel-control-system__self-diagnostic-function) ).
3. Sort, and then troubleshoot the DTCs in the order below. Battery voltage DTCs Internal error DTCs Loss of communication DTCs (beginning with the lowest number first; for example, if B1006 and B1059 are retrieved, troubleshoot B1006 first) Signal error DTCs
4. If no DTCs are retrieved, use B-CAN System Diagnosis Test Mode 2 to check all inputs related to failure (see step 11 ).

Loss of Communication DTC Cross-Reference Table

When an ECU is unable to communicate with the other ECUs on the circuit, the other units will set loss of communication DTCs. Use this LOSS OF COMMUNICATION DTC CROSS-REFERENCE TABLE to find the control unit that is not communicating.

1. Find the Transmitting Unit that is in the same row as all of the loss of communication DTCs retrieved.
2. Perform the input test for the transmitting unit.

LOSS OF COMMUNICATION DTC CROSS-REFERENCE TABLE

DTC Troubleshooting Index

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

1. Battery voltage DTCs
2. Internal error DTCs
3. Loss of communication DTCs (beginning with the lowest number first; for example, if B1006 and B1059 are retrieved, troubleshoot B1006 first).
4. Signal error DTCs

DTC TROUBLESHOOTING INDEX

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 4

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 5

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. Multiplex integrated control unit (MICU)
4. Door multiplex control unit
5. Combination switch control unit
6. Display panel control unit
7. Hands Free Link control unit
8. Power seat control unit

F-CAN ECUs

Scheme 6

1. Gauge control module
2. ECM/PCM
3. Navigation unit
4. VSA modulator-control unit
5. TPMS control unit ('06 model)

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). After the switch to ON, 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 the control units did not communicate.

Scheme 7

1. Ignition switch is turned ON (II).
2. The door multiplex control unit transmits a door switch signal.
3. The multiplex integrated control unit (MICU), relay control module, and gauge control module receive the door lock switch signal.
4. The communication circuit test is passed.
5. Ignition switch is turned ON (II).
6. The door multiplex control unit transmits a door switch signal.
7. The multiplex integrated control unit (MICU), relay control module, and gauge control module expect to receive the door lock switch signal, 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 signal from the door multiplex control unit will transmit DTCs for the signal that it did not receive.

Since there is a break in the communication circuit, the door lock switch signal could not be received by the gauge control module, multiplex integrated control unit (MICU), or the relay control module. Each of these units will set "loss of communication" error codes for the signal(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 door multiplex control unit sends the keyless panic signal and door lock switch signal during the communication circuit test.

Diagnostic Trouble Codes (DTC)

There are three types of DTCs used by the CAN networks.

CAN NETWORKS - DIAGNOSTIC TROUBLE CODES

B-CAN System Switch Device Index

B-CAN SYSTEM SWITCH DEVICE INDEX - COMBINATION SWITCH CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - RELAY CONTROL MODULE

B-CAN SYSTEM SWITCH DEVICE INDEX - DOOR MULTIPLEX CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - MULTIPLEX INTEGRATED CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - DISPLAY PANEL CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - GAUGE CONTROL MODULE

B-CAN SYSTEM SWITCH DEVICE INDEX - CLIMATE CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - POWER SEAT CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - POWER MIRROR CONTROL UNIT

B-CAN SYSTEM SWITCH DEVICE INDEX - HANDS FREE LINK CONTROL UNIT

HDS Inputs and Commands

HDS INPUTS AND COMMANDS

Output

HDS OUTPUTS AND COMMANDS

Troubleshooting - B-CAN System Diagnosis Test Mode A

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

Note. Always cycle 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 Hands Free Link 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 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 Honda Diagnostic System (HDS), then turn the ignition switch ON (II).
3. From the BODY ELECTRICAL SYSTEM SELECTION MENU, select UNIT INFORMATION, and then select CONNECTED UNIT listed to see if it is communicating with the HDS. MICU Door multiplex control unit Gauge control module Combination switch control unit Relay control module Display panel control unit Power seat control unit Hands Free Link control unit NOTE: If the unit is communicating with the scan tool or the HDS, DETECT will be displayed. If the unit is not communicating, "Not Available" will be displayed. Are all control units communicating with the HDS? YES - Go to step 4 . NO - If all units are not communicating, or if only the MICU is detected, go to DTC B1000 troubleshooting (see «DTC B1000: Communication Bus Line Error (BUS Off)»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__dtc-b1000-communication-bus-line-error) ).
4. Select the system that has the problem from the BODY ELECTRICAL SYSTEM SELECTION 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»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__troubleshooting-b-can-system-diagnosis-test) ). 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 Hands Free Link
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. Begin troubleshooting with the lowest number first (Example: if DTCs B1006 and B1058 are retrieved, begin by troubleshooting B1006). 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 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 SELECTION MENU.
2. Select DTCs, and then check for loss of communication DTCs. Are any loss of communication DTCs indicated? YES - Go to step 3 . NO - Replace the MICU.
3. Perform the input test for the unit not communicating with the HDS. UNIT NOT COMMUNICATING WITH HDS Unit not communicating MICU (see «MICU INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__micu-input-test) ) Door multiplex control unit (see «DOOR MULTIPLEX CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__door-multiplex-control-unit-input-test) ) Gauge control module (see «GAUGE CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) ) Relay control module (see «RELAY CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) ) Display panel control unit (see «DISPLAY AND CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/gauges-instrument-panels/#display-panel-control-system__display-and-control-unit-input-test) ) Combination switch control unit (see «COMBINATION SWITCH CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) ) Power seat control unit (see «POWER SEAT CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/memory-modules/#driving-position-memory-systems-dpms__power-seat-control-unit-input-test) ) Hands Free Link control unit (see «CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#handsfree-link-system__control-unit-input-test) )

Troubleshooting - B-CAN System Diagnosis Test Mode C

Perform 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 SWITCH DEVICE INDEX ). Always cycle 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»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__troubleshooting-b-can-system-diagnosis-test) ). 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 «HDS INPUTS AND COMMANDS»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__hds-inputs-and-commands) ).
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

Perform this diagnosis 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 SWITCH DEVICE INDEX ). Always cycle 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»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__troubleshooting-b-can-system-diagnosis-test) ). 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. Are the relay and circuit OK? YES - Go to step 6 . NO - Replace the relay or repair the wire circuit.
6. Perform 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 - 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.

Test Mode 1

Perform this diagnosis if the HDS is not available.

Scheme 8

1. Check the No. 7 (7.5 A) fuse and No. 21 (7.5 A) fuse in the under-dash fuse/relay box. Are the fuses OK? YES - Go to step 2 . NO - Find and repair the cause of the blown fuse.
2. Remove the left kick panel (see «TRIM REMOVAL/INSTALLATION - DOOR AREAS»(/acura/tl/iii-2003-2006/remont/exteriorinterior-trim/#interior-trim__trim-removalinstallation-door-areas) ).
3. Turn the ignition switch ON (II), and move the interior light switch in middle position.
4. Connect the MPCS service connector (A) to the MCIC socket (B) in the under-dash fuse/relay box.
5. Wait 5 seconds, and watch the map lights. When the system enters Mode 1, the front and rear map lights will flash quickly once, and a double beep will be heard.
6. If there is a DTC, the map lights and ignition key light will blink, pause, then repeat the DTC as long as the ignition switch ON (II). Is there a repeating DTC? YES - Count the blinks, then go to step 7 . NO - Go to step 8 .
7. About 1 second after you go into Test Mode 1, the map lights will indicate the DTC, and repeat it every 3 seconds. If there is more than one DTC, the system will indicate them in ascending order, beginning from the DTC with the lowest numerical value. Troubleshoot the DTCs as indicated below: DTC 2, 3, 4 and 5 simultaneously: Check for an open in the BLU wire between multiplex integrated control unit D11 and relay control module K7, BRN/BLK wire between multiplex integrated control unit J4 and door multiplex control unit A5, LT GRN wire between multiplex integrated control unit X27 and combination switch control unit No. 4, BRN/YEL wire between multiplex integrated control unit N28 and gauge B11. If the wire is OK, substitute a known-good under-dash fuse/relay box (multiplex integrated control unit), under-hood fuse/relay box, power window master switch, wiper/washer switch and gauge one at a time, in that order, and recheck for the DTCs after each substitution. DTC 1 only: Go to «MICU INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__micu-input-test) . DTC 2 only (no other DTCs present): Go to the «RELAY CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . If all inputs are OK, substitute a known-good relay control module and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit. DTC 3 only (no other DTCs present): Go to the «DOOR MULTIPLEX CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__door-multiplex-control-unit-input-test) . If all inputs are OK, substitute a known-good door multiplex control unit and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit. DTC 4 only (no other DTCs present): Go to the «COMBINATION SWITCH CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . If all inputs are OK, substitute a known-good wiper/washer switch and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit. DTC 5 only (no other DTCs present): Go to the «GAUGE CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . If all inputs are OK, substitute a known-good gauge control module and then a MICU, one at a time, and then check for DTCs. If a DTC recurs after a substitution, replace that unit. DTC AND CAUSES DTC Cause 1 The MICU cannot receive signals from the BUS communication line. 2 The MICU cannot receive signals from the relay control module communication line. 3 The MICU cannot receive signals from the power window communication line. 4 The MICU cannot receive signals from the combination switch communication line. 5 The MICU cannot receive signals from the gauge control module.
8. Check for B-CAN DTCs indicated by the gauge control module while still in Test Mode 1 (see «GAUGE CONTROL MODULE DTC DISPLAY»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__gauge-control-module-dtc-display) ). Are any DTCs indicated? YES - Go to step 9 . NO - Go to step 11 .
9. Record all DTCs and sort them by type.
10. Troubleshoot the DTCs in these order: Battery voltage DTCs Internal error DTCs Loss of communication DTCs (begin with the lowest number first; for example, if B1006 and B1059 are retrieved, troubleshoot B1006 first) Signal error DTCs
11. Remove the MPCS service connector from the under-dash fuse/relay box socket for 5-10 seconds, then re-insert it to enter Test Mode 2. When the system enters Test Mode 2, the front and rear map lights will flash two times quickly. NOTE: If the MPCS service connector is disconnected for too short or too long of a time, or the ignition switch is turned OFF, the system will return to «TEST MODE 1»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__test-mode-1) .
12. In the table below is a list of 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 map lights will blink once. If the circuit is faulty, there will be no indication. MICU MICU ITEM LIST Item Driver's door switch (OPEN) Front passenger's door switch (OPEN) Left rear door switch (OPEN) Right rear door switch (OPEN) Trunk lid latch switch (OPEN) Front passenger's door lock knob switch (UNLOCK) (1) Left rear door lock knob switch (UNLOCK) (1) Right rear door lock knob switch (UNLOCK) (1) Audio-HVAC display module security ground (disconnected) Driver's seat belt switch (unbuckled) Brake pedal position switch (ON; brake pedal pressed) Passenger's door lock switch (LOCK/UNLOCK) (1) The front passenger's and rear door lock knob switches must be in the locked position when beginning the test. RELAY CONTROL MODULE RELAY CONTROL MODULE ITEM Item Windshield wiper switch (AUTO STOP/PARK) Hood switch (open) A/C pressure switch/thermal protector (A/C ON) COMBINATION SWITCH CONTROL UNIT COMBINATION SWITCH CONTROL UNIT ITEM Item Turn signal switch (LEFT) Turn signal switch (RIGHT) Combination light switch (ON; each position) Dimmer switch (ON) Passing switch (ON) Windshield wiper switch (ON) Intermittent wiper dwell timer Windshield washer switch (ON) POWER WINDOW MASTER SWITCH (DOOR MULTIPLEX CONTROL UNIT) POWER WINDOW MASTER SWITCH (DOOR MULTIPLEX CONTROL UNIT) ITEM Item Power window master switch (Driver's window UP) Power window master switch (Driver's window DOWN) Power window master switch (Driver's window AUTO UP) Power window master switch (Driver's window AUTO DOWN) Power window master switch (Front passenger's window UP) Power window master switch (Front passenger's window DOWN) Power window master switch (Left rear window UP) Power window master switch (Left rear window DOWN) Power window master switch (Right rear window UP) Power window master switch (Right rear window DOWN) Driver's door key cylinder switch (1) (LOCK) Driver's door key cylinder switch (1) (UNLOCK) Driver's door lock switch (LOCK) Driver's door lock switch (UNLOCK) Driver's door lock knob switch (LOCK) Driver's door lock knob switch (UNLOCK) Driver's position memory switches (1, 2, memo) Passenger's power window switch Passenger's power window switch (UP) Passenger's power window switch (DOWN) Passenger's power window switch (AUTO UP) Passenger's power window switch (AUTO DOWN) (1) A second key is necessary to check the key cylinder inputs. Be sure to rotate the key cylinder switch two times to each position (lock and lock, unlock and unlock) to ensure the door lock knob switch is in the appropriate position. GAUGE CONTROL MODULE GAUGE CONTROL MODULE ITEM Item Parking brake switch (ON; parking brake applied) Cruise control main SET/RESUME/CANCEL switch (ON; switch pressed) Transmission range switch (P, R, N, D) Washer fluid level switch (fluid removed) (Canada) Brake fluid level switch (fluid removed) Illumination control switches (+, -, MAX) MID switches (Select/Reset, < INFO, INFO >) POWER SEAT CONTROL UNIT POWER SEAT CONTROL UNIT ITEM Item Power seat slide switch (Forward, Backward) Power seat front up-down switch (UP, Down) Power seat rear up-down switch (UP, Down) Power seat recline switch (Forward, Recline) POWER MIRROR CONTROL UNIT POWER MIRROR CONTROL UNIT LIST Item Mirror select switch (Left, Center, Right) Mirror switch (Left, Right, Up, Down) Does the map lights indicate proper switch operation? YES - Go to function and input test for the system related to the failure. NO - Repair the open, short, or replace the faulty switch.

Gauge Control Module DTC Display

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 Multiplex Integrated Control Unit (MICU) and the gauge control module are normal. To scroll through the DTCs, press the SELECT/RESET button beside the gauge control module.

Scheme 9

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

CONTROL UNIT AND I.D. NUMBER

How to Clear the DTC

While in Test Mode 1, press and hold down the SELECT/RESET button for more than 13 seconds.

Scheme 10

Scheme 11

DTC Troubleshooting

DTC TROUBLESHOOTING INDEX

DTC B1000: Communication Bus Line Error (BUS Off)

1. Clear the DTCs with the HDS.
2. Turn the ignition switch OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Go to step 4 . NO - Intermittent failure. The communication bus line is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Are DTCs B1005, B1006, B1007, B1008, B1010, and B1011 indicated? YES - Go to step 5 . NO - Replace the MICU.
5. 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. APPROPRIATE CONNECTOR AND CONTROL UNIT Control Unit Appropriate Connector Gauge Control Module Connector B (18P) Relay Control Module Connector K (10P) Door Multiplex Control Unit Power window master switch connector A (22P) Combination switch Control Unit Connector (8P) Power Seat Control Unit Connector A (20P) Display Panel Control Unit Connector A (14P) HandsFreeLink Control Unit Connector (22P) Is DTC B1000 indicated with each individual unit disconnected? YES - Go to step 6 . NO - Replace the control unit that was disconnected and B1000 did not reset.
6. Disconnect all of the appropriate connectors for each of the units in the table. APPROPRIATE CONNECTOR AND CONTROL UNIT Control Unit Appropriate Connector Gauge Control Module Connector B (18P) Relay Control Module Connector K (10P) Door Multiplex Control Unit Power window master switch connector A (22P) Combination Switch Control Unit Connector (8P) Power Seat Control Unit Connector A (20P) Display Panel Control Unit Connector A (14P) HandsFreeLink Control Unit Connector (22P)
7. Disconnect under-dash fuse/relay box connectors X (39P), N (45P), J (30P), G (8P), D (17P).
8. Check for continuity between each of the under-dash fuse/relay box terminals listed in «CONNECTED CONTROL UNIT AND UNDER-DASH FUSE/RELAY BOX TERMINAL»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . CONNECTED CONTROL UNIT AND UNDER-DASH FUSE/RELAY BOX TERMINAL Connected Control Unit Under-dash fuse/relay box terminal Gauge Control Module N28 Relay Control Module D11 Door Multiplex Control Unit J4 Combination Switch Control Unit X27 Power Seat Control Unit G1 Display Panel Control Unit N22 HandsFreeLink Control Unit X18 Is there continuity? YES - Repair a short in the wire between the under-dash fuse/relay box and the connected control unit. NO - Go to step 9 .
9. Check for voltage between each of the under-dash fuse/relay box terminals listed in the table above and body ground. Is there 1 V or less? YES - Replace the under-dash fuse/relay box. NO - Repair a short in the wire between the under-dash fuse/relay box and the connected control unit.

DTC B1050: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1050 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at relay control module connector K (10P), and at under-dash fuse/relay box connector D (17P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1050 is indicated, replace the relay control module.

DTC B1100: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1100 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at door multiplex connector A (22P), and at under-dash fuse/relay box connector J (30P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1100 is indicated, replace the door multiplex control unit.

DTC B1150: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1150 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at gauge control module connector B (18P), and at under-dash fuse/relay box connector N (45P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1150 is indicated, replace the gauge control module.

DTC B1250: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1250 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at combination switch control unit connector (8P), and at under-dash fuse/relay box connector X (39P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1250 is indicated, replace the combination switch control unit.

DTC B1700: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1700 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at display panel control unit connector A (14P), and at under-dash fuse/relay box connector N (45P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1700 is indicated, replace the display panel control unit.

DTC B1750: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1750 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at HandsFreeLink control unit connector (22P), and at under-dash fuse/relay box connector X (39P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1750 is indicated, replace the Hands Free Link control unit.

DTC B1800: 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1800 indicated? YES - Go to step 4 . NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections at power seat control unit connector A (22P), and at under-dash fuse/relay box connector G (6P).
4. Check for DTCs with the HDS. Is DTC B1000 indicated? YES - Troubleshoot DTC B1000. NO - If the B1800 is indicated, replace the power seat control unit.

DTC B1001: Multiplex Integrated Control Unit (MICU) Internal Error (CPU 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 OFF, and then back ON (II).
3. Operate the door lock (LOCK/UNLOCK).
4. Check for DTCs with the HDS. Is DTC B1001 indicated? YES - Faulty MICU; replace the under-dash fuse/ relay box. NO - Intermittent failure, the MICU is OK at this time. Check for loose or poor connections. If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.

DTC B1002: Multiplex Integrated Control Unit (MICU) Internal Error (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 OFF, and then back ON (II).
3. Operate the door lock (LOCK/UNLOCK).
4. Check for DTCs with the HDS. Is DTC B1002 indicated? YES - Faulty MICU; replace the under-dash fuse/relay box. NO - Intermittent failure, the MICU is OK at this time. Check for loose or poor connections. If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.

DTC B1102: Door Multiplex Control Unit Internal 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 OFF, and then back ON (II).
3. Operate the power window (UP/DOWN).
4. Check for DTCs with the HDS. Is DTC B1102 indicated? YES - Faulty door multiplex control unit; replace the power window master switch. NO - Intermittent failure, the door multiplex control unit is OK at this time. Check for loose or poor connections. If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.

DTC B1005: MICU Lost Communication with Relay 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1005 indicated? YES - Go to step 4 . NO - Intermittent failure, the relay control module is OK at this time. Check for loose or poor connection at relay control module connector K (10P), and at under-dash fuse/relay box connector D (17P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Is DTC B1158 indicated? YES - Go to «RELAY CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . NO - Check for an open or loose connection in the communication circuit between the MICU and the relay control module. If the circuit is OK, replace the MICU. If the circuit is bad, repair the open.

DTC B1006: MICU Lost Communication with Door Multiplex Control Unit (Door Lock Switch Message)

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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1006 indicated? YES - Go to step 4 . NO - Intermittent failure, the door multiplex control unit is OK at this time. Check for loose or poor connection at door multiplex connector A (22P), and at under-dash fuse/relay box connector J (30P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Are DTCs B1160 and B1058 indicated? YES - Go to «DOOR MULTIPLEX CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__door-multiplex-control-unit-input-test) ). NO - Check for an open or loose connection in the communication circuit between the MICU and the door multiplex control unit. If the circuit is OK, replace the MICU. If the circuit is bad, repair the open.

DTC B1007: MICU Lost Communication with Combination Switch Control Unit (Headlight Switch Message)

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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1007 indicated? YES - Go to step 4 . NO - Intermittent failure, the MICU is OK at this time. Check for loose or poor connection at combination switch control unit connector (8P), and at under-dash fuse/relay box connector X (39P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Are DTCs B1155 and B1062 indicated? YES - Go to the «COMBINATION SWITCH CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . NO - Check for an open in the communication circuit between the MICU and the combination switch control unit. If the circuit is OK, replace the MICU. If the circuit is bad, repair the open.

DTC B1008: MICU Lost Communication with Gauge Control Module (A/T Message)

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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1008 indicated? YES - Go to step 4 . NO - Intermittent failure, the gauge control module is OK at this time. Check for loose or poor connection at gauge control module connector B (18P), and at under-dash fuse/relay box connector N (45P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Are DTCs B1061 and B1808 indicated? YES - Go to the «GAUGE CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . NO - Check for an open in the communication circuit between the MICU and the gauge control module. If the circuit is OK, replace the MICU. If the circuit is bad, repair the open.

DTC B1010: MICU Lost Communication with Door Multiplex Control Unit (Panic Message)

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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1010 indicated? YES - Go to step 4 . NO - Intermittent failure, the door multiplex control unit is OK at this time. Check for loose or poor connection at door multiplex connector A (22P), and at under-dash fuse/relay box connector J (30P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Is DTC B1059 indicated? YES - Go to the «DOOR MULTIPLEX CONTROL UNIT INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__door-multiplex-control-unit-input-test) . NO - Check for an open or loose connection in the communication circuit between the MICU and the door multiplex control unit. If the circuit is OK, replace the MICU. If the circuit is bad, repair the open.

DTC B1011: MICU Lost Communication with Gauge Control Module (VSP/NE Message)

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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1011 indicated? YES - Go to step 4 . NO - Intermittent failure, the gauge control module is OK at this time. Check for loose or poor connection at gauge control module connector B (18P), and at under-dash fuse/relay box connector N (45P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Are DTCs B1060, B1706 and B1805 indicated? YES - Go to the «GAUGE CONTROL MODULE INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system) . NO - Check for an open, or loose connection, or a short to power or ground in the communication circuit between the MICU and the gauge control module. If the circuit is OK, replace the MICU. If the circuit is bad, repair the open, or short to power or ground.

DTC B1080: Power Supply Circuit (IG1 Line) Input Error for Relay Control Module and 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 ).

Scheme 12

Scheme 13

1. Clear the DTC with the HDS.
2. Turn the ignition switch OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1080 indicated? YES - Go to step 4 . NO - Intermittent failure, check for loose or poor connections at the relay control module connector K (10P) and under-dash fuse/relay box connector D (17P). If the connections are OK, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check the MICU IG1 power supply No. 21 (7.5 A) fuse in the under-dash fuse/relay box. Is the fuse OK? YES - Go to step 5 . NO - Replace the fuse and recheck for DTCs.
5. Measure voltage between the No. 8 terminal of the under-hood fuse/relay box connector K (10P) and body ground. Is there battery voltage? YES - Go to step 6 . NO - Open in the wire between the under-hood fuse/relay box and the under-dash fuse/relay box. Repair the wire and recheck for DTCs.
6. Check the voltage between the No. 10 terminal of the under-hood fuse/relay box connector K (10P) and body ground. Is there less than 1 V? YES - Faulty relay control module; replace the under-hood fuse/relay box. NO - Open or loose connection in the wire between the under-hood fuse/relay box and G503, G601. If the wire is OK, inspect the G503 and G601.

DTC B1255: Combination Switch Control Unit Lost Communication With 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 OFF, and then back ON (II).
3. Check for DTCs with the HDS. Is DTC B1255 indicated? YES - Go to step 4 . NO - Intermittent failure, MICU is OK at this time. Check for loose or poor connection at combination switch control unit connector (8P), and at under-dash fuse/relay box connector X (39P). If the connections are good, check the battery condition (see «BATTERY TEST»(/acura/tl/iii-2003-2006/remont/body-electrical/#battery) ) and the charging system.
4. Check for DTCs with the HDS. Are DTCs B1055, B1157 and B1806 indicated? YES - Go to «MICU INPUT TEST»(/acura/tl/iii-2003-2006/remont/communication-devices/#multiplex-intergrated-control-system__micu-input-test) . NO - Replace the combination switch control unit.

MICU Input Test

Note. Make sure the ignition switch is OFF before troubleshooting the under-dash fuse/relay box connectors.

Scheme 14

1. Remove the left kick panel (see «TRIM REMOVAL/INSTALLATION - DOOR AREAS»(/acura/tl/iii-2003-2006/remont/exteriorinterior-trim/#interior-trim__trim-removalinstallation-door-areas) ).
2. Disconnect the under-dash fuse/relay box connectors D, E, F, G, H, J, K, M, N, P, W and X. NOTE: All connectors are wire side of female terminals.
3. 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 4 .
4. Reconnect the connectors to the under-dash fuse/relay box, and make sure these input tests at the appropriate connectors on the under-dash fuse/relay box. 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 5 . MICU INPUT TEST - REFERENCE DATA Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained P7 WHT/BLK Under all conditions Attach to ground: The ignition key light should come on. Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box Faulty LED An open in the wire W4 GRIM/RED Interior light switch in the middle position, all doors closed Attach to ground: The individual map lights should come on. Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box Faulty map light An open in the wire D6 X34 YEL Ignition switch ON (II) Check for voltage to ground: There should be battery voltage. Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire K5 X35 WHT/RED Under all conditions Check for voltage to ground: There should be battery voltage. Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire F8 YEL/GRN Ignition switch ON (II) Check for voltage to ground: There should be battery voltage. Blown No. 20 (1) fuse in the under-dash fuse/relay box An open in the wire X24 GRN/WHT Under all conditions Check for voltage to ground: There should be battery voltage. Blown No. 27 (30 A) fuse in the under-dash fuse/relay box An open in the wire E9 H9 BLK Under all conditions Check for voltage to ground: There should be less than 1 V. Poor ground (G503, G601) An open in the wire P1 BLK Under all conditions Check for voltage to ground: There should be less than 1 V. Poor ground (G502) An open in the wire (1) No. 20 (7.5 A): '04-05 models No. 20 (15 A): '06 model MICU INPUT TEST - REFERENCE DATA Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained N22 LT BLU Under all conditions Check for continuity between terminal N22 and center panel control unit connector A (14P) No. 14 terminal: There should be continuity. An open in the wire Display panel control unit connector A (14P) disconnected Check for continuity to ground: There should be no continuity. Short to ground N28 BRN/YEL Under all conditions Check for continuity between terminal N28 and gauge control module connector B (18P) No. 11 terminal: There should be continuity. An open in the wire Gauge control module connector B (18P) disconnected Check for continuity to ground: There should be no continuity. Short to ground X18 RED/WHT Under all conditions Check for continuity between terminal X18 and HandsFreeLink control unit connector (22P) No. 14 terminal: There should be continuity. An open in the wire HandsFreeLink control unit connector (22P) disconnected Check for continuity to ground: There should be no continuity. Short to ground X27 LT GRN Under all conditions Check for continuity between terminal X27 and wiper/washer connector (8P) No. 4 terminal: There should be continuity. An open in the wire Wiper/washer switch connector (8P) disconnected Check for continuity to ground: There should be no continuity. Short to ground
5. Disconnect the under-dash fuse/relay box connector D, G, and J, and make these input tests at the connector(s). If any test indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, the multiplex integrated control unit must be faulty. Replace the under-dash fuse/relay box. MICU INPUT TEST - REFERENCE DATA Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained D11 BLU Under all conditions Check for continuity between terminal D11 and relay control module connector K (10P) No. 7 terminal: There should be continuity. An open in the wire Relay control module connector K (10P) disconnected Check for continuity to ground: There should be no continuity. A short to ground in the wire G1 PNK Under all conditions Check for continuity between terminal G1 and power seat control unit connector A (20P) No. 14 terminal: There should be continuity. An open in the wire Power seat control unit connector A (20P) disconnected Check for continuity to ground: There should be no continuity. A short to ground in the wire J4 BRN/BLK Under all conditions Check for continuity between terminal J4 and power window master switch connector A (22P) No. 5 terminal: There should be continuity. An open in the wire Power window master switch (Door multiplex control unit) connector (22P) disconnected Check for continuity to ground: There should be no continuity. A short to ground in the wire

Scheme 15

1. Remove the gauge control module (see «GAUGE CONTROL MODULE REPLACEMENT»(/acura/tl/iii-2003-2006/remont/gauges-instrument-panels/#display-and-gauge-system) ).
2. Disconnect the 18P connector from the gauge control module.
3. 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 4 .
4. Reconnect the connector, and make these input tests at the connector. 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 5 . GAUGE CONTROL MODULE INPUT TEST - REFERENCE DATA Cavity Wire Test Condition Test: Desired result Possible cause if result is not obtained B17 WHT/RED Under all conditions Check for voltage to ground: There should be battery voltage. Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire B18 YEL Ignition switch ON (II) Check for voltage to ground: There should be battery voltage. Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire B1 BLK Under all conditions Check for voltage to ground: There should be less than 1 V. Poor ground (G501) An open in the wire B10
5. Disconnect the 18P connector from the gauge control module, and make these input tests at the connector. If any test indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, replace the gauge control module. GAUGE CONTROL MODULE INPUT TEST - REFERENCE DATA Cavity Wire Test Condition Test: Desired result Possible cause if result is not obtained B11 BRN/YEL Under all conditions Check for continuity between the B11 terminal and under-dash fuse/relay box connector N (45P) No. 28 terminal: There should be continuity. An open in the wire

Door Multiplex Control Unit Input Test

Note. Make sure the ignition switch is OFF before disconnecting the driver's door switch panel.

Scheme 16

1. Remove the driver's door switch panel (see «FRONT DOOR PANEL REMOVAL/INSTALLATION»(/acura/tl/iii-2003-2006/remont/windows/#door-system__front-door-panel-removalinstallation) ).
2. Disconnect the connectors from the power window master switch.
3. 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 4 .
4. Reconnect the connector and, make these input tests at the connector. 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 5 . DOOR MULTIPLEX CONTROL UNIT INPUT TEST - REFERENCE DATA Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained B3 WHT/RED Under all conditions Check for voltage to ground: There should be battery voltage. Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire B11 GRN/WHT Under all conditions Check for voltage to ground: There should be battery voltage. Blown No. 27 (30 A) fuse in the under-dash fuse/relay box An open in the wire B14 BLK Under all conditions Check for voltage to ground: There should be less than 1 V. Poor ground (G501) An open in the wire
5. Disconnect the connector from the door multiplex control unit, and make these input tests at the connector.

1. If any test indicates a problem, find and correct the cause, then recheck the system.
2. If all the input tests prove OK, the door multiplex control unit must be faulty. Replace the power window master switch.

DOOR MULTIPLEX CONTROL UNIT INPUT TEST - REFERENCE DATA

Scheme 17

1. Remove the steering column covers (see «STEERING COLUMN REMOVAL AND INSTALLATION»(/acura/tl/iii-2003-2006/remont/manual-power-steering/#power-steering-system__steering-column-removal-and-installation) ).
2. Disconnect the 8P connector from the wiper/washer switch.
3. 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 4 .
4. Reconnect the connector, and make these input tests at the connector. 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 5 . COMBINATION SWITCH CONTROL UNIT INPUT TEST - REFERENCE DATA Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained 3 BLK Under all conditions Check for voltage to ground: There should be less than 1 V. Poor ground (G503, G601) An open in the wire 8 WHT/RED Under all conditions Check for voltage to ground: There should be battery voltage. Blown No. 7 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire 7 YEL Ignition switch ON (II) Check for voltage to ground: There should be battery voltage. Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire
5. Disconnect the connector from the wiper/washer switch, and make these input tests at the connector. If any test indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, the combination switch control unit must be faulty, replace the wiper/washer switch.

COMBINATION SWITCH CONTROL UNIT INPUT TEST - REFERENCE DATA

Scheme 18

1. Remove the under-hood fuse/relay box undercover (see «REMOVAL AND INSTALLATION»(/acura/tl/iii-2003-2006/remont/body-electrical/#under-hood-fuserelay-box) ).
2. Disconnect the under-hood fuse/relay box connector K (10P).
3. 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 4 .
4. Reconnect the connector, and make these input tests at the connector. 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 5 . RELAY CONTROL MODULE INPUT TEST - REFERENCE DATA Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained K10 BLK Under all conditions Check for voltage to ground: There should be less than 1 V. Poor ground (G503, G601) An open in the wire K8 YEL Ignition switch ON (II) Check for voltage to ground: There should be battery voltage. Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box An open in the wire
5. Disconnect the 10P connector from the under-hood fuse/relay box, and make these input tests at the connector. If any test indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, the relay module must be faulty, replace the under-hood fuse/relay box.

RELAY CONTROL MODULE INPUT TEST - REFERENCE DATA

See also:
• GENERAL TROUBLESHOOTING INFORMATION
• SELF-DIAGNOSTIC FUNCTION
• SELF-DIAGNOSTIC FUNCTION
• DTC B1026: PASSENGER'S DOOR LOCK SWITCH SIGNAL ERROR
• B1055: RELAY CONTROL MODULE LOST COMMUNICATION WITH MICU
• DTC B1075: HEADLIGHT SIGNAL ERROR
• DTC B1076: WINDSHIELD WIPER SIGNAL ERROR
• DTC B1077: WINDSHIELD WIPER (AS) SIGNAL ERROR
• DTC B1125: DRIVER'S POWER WINDOW MOTOR A PULSE ERROR
• DTC B1126: DRIVER'S POWER WINDOW MOTOR B PULSE ERROR
• DTC B1127: DRIVER'S DOOR KEY CYLINDER SWITCH SIGNAL ERROR
• DTC B1128: DRIVER'S DOOR LOCK SWITCH SIGNAL ERROR
• DTC B1129: DRIVER'S DOOR LOCK KNOB SWITCH SIGNAL ERROR
• 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 ERROR
• DTC B1141: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH FRONT PASSENGER'S POWER WINDOW SWITCH (UART LINE SHORT)
• DTC B1142: DOOR MULTIPLEX CONTROL UNIT LOST COMMUNICATION WITH FRONT PASSENGER'S POWER WINDOW SWITCH (UART LINE OPEN)
• DTC B1143: DOOR MULTIPLEX CONTROL UNIT INTERNAL ERROR (EEPROM ERROR)
• DTC B1144: ABNORMAL SIGNAL FROM KEYLESS RECEIVER UNIT
• DTC B1145: FRONT PASSENGER'S POWER WINDOW POSITION DETECT CIRCUIT ERROR
• DTC B1146: FRONT PASSENGER'S POWER WINDOW SWITCH MALFUNCTION
• DTC B1152: GAUGE CONTROL MODULE EEPROM ERROR
• DTC B1155: GAUGE CONTROL MODULE LOST COMMUNICATION WITH COMBINATION SWITCH CONTROL UNIT (HEADLIGHT SWITCH MESSAGE)
• DTC B1156: GAUGE CONTROL MODULE LOST COMMUNICATION WITH COMBINATION SWITCH CONTROL UNIT (WIPER SWITCH MESSAGE)
• DTC B1157: GAUGE CONTROL MODULE LOST COMMUNICATION WITH MULTIPLEX INTEGRATED CONTROL UNIT (MICU)
• DTC B1158: GAUGE CONTROL MODULE LOST COMMUNICATION WITH RELAY CONTROL MODULE
• DTC B1159: GAUGE CONTROL MODULE LOST COMMUNICATION WITH MULTIPLEX INTEGRATED CONTROL UNIT (MICU) (DOOR SWITCH MESSAGE)
• DTC B1160: GAUGE CONTROL MODULE LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT (DOOR LOCK SWITCH MESSAGE)
• DTC B1168: GAUGE CONTROL MODULE LOST COMMUNICATION WITH ECM/PCM (ENGINE MESSAGES)
• DTC B1169: GAUGE CONTROL MODULE LOST COMMUNICATION WITH PCM (A/T MESSAGES)
• DTC B1170: GAUGE CONTROL MODULE LOST COMMUNICATION WITH VSA MODULATOR-CONTROL UNIT (VSA MESSAGE)
• DTC B1173: GAUGE CONTROL MODULE LOST COMMUNICATION WITH TPMS CONTROL UNIT (TPMS MESSAGES)
• DTC B1175: FUEL LEVEL SENSOR (FUEL GAUGE SENDING UNIT) SIGNALS INPUT ERROR
• DTC B1177: ABNORMAL BATTERY VOLTAGE (7.5 V)
• DTC B1178: F-CAN COMMUNICATION LINE ERROR
• DTC B1202: CLIMATE CONTROL UNIT INTERNAL ERROR
• DTC B1225 OR DTC INDICATOR A: AN OPEN IN THE IN-CAR TEMPERATURE SENSOR CIRCUIT
• DTC B1235 OR DTC INDICATOR K: A PROBLEM IN THE DRIVER'S AIR MIX CONTROL LINKAGE, DOOR, OR MOTOR
• DTC B1238 OR DTC INDICATOR N: A PROBLEM IN THE PASSENGER'S AIR MIX CONTROL LINKAGE, DOOR, OR MOTOR
• DTC B1240 OR DTC INDICATOR P: A PROBLEM IN THE DRIVER'S MODEL CONTROL LINKAGE, DOORS, OR MOTOR
• DTC B1243 OR DTC INDICATOR R: A PROBLEM IN THE PASSENGER'S MODE CONTROL LINKAGE, DOORS, OR MOTOR
• DTC B1275: HEADLIGHT SWITCH OFF POSITION CIRCUIT MALFUNCTION
• DTC B1276: HEADLIGHT SWITCH PARKING (SMALL) POSITION CIRCUIT MALFUNCTION
• DTC B1278: HEADLIGHT SWITCH ON POSITION CIRCUIT MALFUNCTION
• DTC B1279: HEADLIGHT SWITCH DIMMER POSITION CIRCUIT MALFUNCTION
• DTC B1280: TURN SIGNAL SWITCH CIRCUIT MALFUNCTION
• DTC B1281, B1282, B1283, B1284: WINDSHIELD WIPER SWITCH MIST POSITION CIRCUIT MALFUNCTION; WINDSHIELD WIPER SWITCH INT (AUTO) POSITION CIRCUIT MALFUNCTION; WINDSHIELD WIPER SWITCH LOW POSITION CIRCUIT MALFUNCTION; WINDSHIELD WIPER SWITCH HIGH POSITION CIRCUIT MALFUNCTION
• DTC B1701: DISPLAY PANEL CONTROL UNIT CPU ERROR
• DTC B1702: DISPLAY PANEL CONTROL UNIT EEPROM ERROR
• DTC B1705: DISPLAY PANEL CONTROL UNIT LOST COMMUNICATION WITH THE GAUGE CONTROL MODULE (ENGINE TEMPERATURE SIGNAL)
• DTC B1706: DISPLAY PANEL CONTROL UNIT LOST COMMUNICATION WITH THE GAUGE CONTROL MODULE (VSS/NE SIGNAL)
• DTC B1725: DISPLAY PANEL CONTROL UNIT TEMPERATURE IS TOO HIGH
• DTC B1751: HANDS FREE LINK CONTROL UNIT CPU ERROR (ANOMALOUS CPU)
• DTC B1775: MICROPHONE INPUT/OUTPUT SHORT TO POWER/OPEN
• DTC B1776: MICROPHONE INPUT/OUTPUT SHORT TO GROUND/OPEN
• DTC B1779: HFL SWITCH OR HFL-VOICE CONTROL SWITCH* (HFL TALK/HFL BACK BUTTONS) OPEN/SHORT
• DTC B1780: HFL SWITCH OR HFL-VOICE CONTROL SWITCH (PICK UP/HANG UP SWITCH) SHORT
• DTC B1792: HANDS FREE LINK CONTROL UNIT INTERNAL ERROR
• DTC B1802: POWER SEAT CONTROL UNIT INTERNAL EEPROM ERROR
• DTC B1805: POWER SEAT CONTROL UNIT LOST COMMUNICATION WITH GAUGE CONTROL MODULE (VSP/NE MESSAGE)
• DTC B1806: POWER SEAT CONTROL UNIT LOST COMMUNICATION WITH MICU (MICU MESSAGE)
• DTC B1807: POWER SEAT CONTROL UNIT LOST COMMUNICATION WITH MICU (DOOR SWITCH MESSAGE)
• DTC B1808: POWER SEAT CONTROL UNIT LOST COMMUNICATION WITH GAUGE CONTROL MODULE (A/T MESSAGE)
• DTC B1809: POWER SEAT CONTROL UNIT LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT (MEMORY SWITCH MESSAGE)
• DTC B1825: SLIDE MOTOR PULSE ERROR
• DTC B1826: FRONT UP-DOWN MOTOR PULSE ERROR
• DTC B1827: REAR UP-DOWN MOTOR PULSE ERROR
• DTC B1828: RECLINE MOTOR PULSE ERROR
• DTC B1829: A/T P SIGNAL AND VSS SIGNAL MISMATCH
• DTC B1830: RIGHT MIRROR HORIZONTAL SENSOR MALFUNCTION
• DTC B1831: RIGHT MIRROR VERTICAL SENSOR MALFUNCTION
• DTC B1832: LEFT MIRROR HORIZONTAL SENSOR MALFUNCTION
• DTC B1833: LEFT MIRROR VERTICAL SENSOR MALFUNCTION
• DTC B1834: M/T HARNESS POOR GROUND
• DTC B1837: POWER SEAT POSITION MEMORY RECALL ERROR
• DTC B1843: POWER SEAT CONTROL UNIT LOST COMMUNICATION WITH OTHER UNITS (UART COMMUNICATION ERROR
• DISPLAY AND CONTROL UNIT INPUT TEST
• POWER SEAT CONTROL UNIT INPUT TEST
• CONTROL UNIT INPUT TEST
• TRIM REMOVAL/INSTALLATION - DOOR AREAS
• BATTERY TEST
• GAUGE CONTROL MODULE REPLACEMENT
• FRONT DOOR PANEL REMOVAL/INSTALLATION
• STEERING COLUMN REMOVAL AND INSTALLATION
• REMOVAL AND INSTALLATION
• TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A
• TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)
• GAUGE CONTROL MODULE DTC DISPLAY
• DTC B1000: COMMUNICATION BUS LINE ERROR (BUS OFF)
• DTC B1001: MULTIPLEX INTEGRATED CONTROL UNIT (MICU) INTERNAL ERROR (CPU ERROR)
• DTC B1002: MULTIPLEX INTEGRATED CONTROL UNIT (MICU) INTERNAL ERROR (EEPROM ERROR)
• DTC B1005: MICU LOST COMMUNICATION WITH RELAY CONTROL MODULE
• DTC B1006: MICU LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT (DOOR LOCK SWITCH MESSAGE)
• DTC B1007: MICU LOST COMMUNICATION WITH COMBINATION SWITCH CONTROL UNIT (HEADLIGHT SWITCH MESSAGE)
• DTC B1008: MICU LOST COMMUNICATION WITH GAUGE CONTROL MODULE (A/T MESSAGE)
• DTC B1010: MICU LOST COMMUNICATION WITH DOOR MULTIPLEX CONTROL UNIT (PANIC MESSAGE)
• DTC B1011: MICU LOST COMMUNICATION WITH GAUGE CONTROL MODULE (VSP/NE MESSAGE)
• DTC B1050: COMMUNICATION BUS LINE ERROR (BUS OFF)
• DTC B1080: POWER SUPPLY CIRCUIT (IG1 LINE) INPUT ERROR FOR RELAY CONTROL MODULE AND MICU
• DTC B1102: DOOR MULTIPLEX CONTROL UNIT INTERNAL ERROR
• DTC B1150: COMMUNICATION BUS LINE ERROR (BUS OFF)
• DTC B1250: COMMUNICATION BUS LINE ERROR (BUS OFF)
• DTC B1255: COMBINATION SWITCH CONTROL UNIT LOST COMMUNICATION WITH MICU
• DTC B1700: COMMUNICATION BUS LINE ERROR (BUS OFF)
• DTC B1750: COMMUNICATION BUS LINE ERROR (BUS OFF)
• DTC B1800: COMMUNICATION BUS LINE ERROR (BUS OFF)
• MICU INPUT TEST
• DOOR MULTIPLEX CONTROL UNIT INPUT TEST
• B-CAN SYSTEM SWITCH DEVICE INDEX
• HDS INPUTS AND COMMANDS
• TEST MODE 1
• DTC B1100