Multiplex Control System: Other Infiniti I30 I

PIN VOLTAGE TESTS

Note. For connector terminal identification, refer to CONNECTOR IDENTIFICATION. see scheme 1- see scheme 3.

PIN VOLTAGE (BCM)

PIN VOLTAGE (LCU01 - DRIVER'S DOOR)

PIN VOLTAGE (LCU02 - PASSENGER'S DOOR)

PIN VOLTAGE (LCU03 - RIGHT REAR DOOR & LCU04 - LEFT REAR DOOR)

PIN VOLTAGE (LCU05 - MULTI-REMOTE SYSTEM)

* PLEASE READ FIRST *

Note. The multiplex control system may also be referred as In-Vehicle Multiplexing System (IVMS), or Local Area Network (LAN) system.

The multiplex control system uses a Body Control Module (BCM) and 5 Local Control Units (LCUs) to manage the following electrical systems: power window, power door lock, multi-remote control, theft warning, step light, rear power window switch illumination, interior light and ignition keyhole illumination, ignition key warning, headlight warning (buzzer), seat belt warning (buzzer), wiper amplifier, rear window defogger timer and self-diagnostic system. See COMPONENT LOCATIONS . Some electrical systems are directly connected to the BCM, while some switches and electrical loads and switches are connected to the appropriate LCU.

The BCM uses 2 data lines ("A" and "B") connected between BCM and LCUs to establish communication and control with each LCU. System has a sleep/wake-up control mode to turn on or shut off the communication between BCM and LCUs, as necessary to prevent unnecessary power consumption. If BCM determines that a signal from an LCU is malfunctioning, system will set appropriate LCU in fail-safe control mode.

BODY CONTROL MODULE (BCM)

The BCM, a master unit of the multiplex control system, has communication and control capabilities. The BCM consists of microprocessor, memory and communication LSI sections. The BCM processes data signals received from the LCUs and sends electrical load data signals to each LCU.

Note. The A/C auto amplifier (if equipped) is built into the BCM. BCM harness connectors are located on the front side of BCM. DO NOT confuse these connectors with A/C auto amplifier harness connectors, located on rear side of BCM.

LOCAL CONTROL UNIT (LCU)

The LCU is a slave unit of the BCM and has a communication capability only. The LCU consists of communication LSI and input/output interface circuits. The LCU uses data signal from BCM to control on/off operation of electrical loads. The LCU also sends a switch signal to BCM to control on/off operation of sleep/wake-up control mode.

SLEEP/WAKE-UP CONTROL MODE

Note. Wake-up control mode can only be diagnosed using Nissan CONSULT scan tool.

The sleep/wake-up control mode allows the communication between BCM and LCUs to be turned on and off as necessary to prevent unnecessary power consumption. When BCM detects that the ignition, electrical loads and timer are off, it will shut off communication with all LCUs and activate sleep mode in about 30 seconds.

Communication with all LCUs will be re-established (system in normal control mode) if BCM detects a wake-up signal from the data line to LCUs, or if a key switch "off" signal (ignition turned from on to off) is detected. The BCM will also re-establish communication with all LCUs if it detects an "on" signal from one of the following switches, which are directly connected to BCM.

1. Key Switch (Key Inserted)
2. Ignition Switch (ACC Or ON)
3. Headlight Switch (First Detent)
4. Door Switches (All)
5. Trunk Lid Unlock Switch
6. Trunk Compartment Light Switch
7. Engine Hood Switch
8. Multi-Remote Controller
9. Door Unlock Sensors (All)

FAIL-SAFE CONTROL MODE

Fail-safe system operates when a signal from LCU is determined to be malfunctioning by BCM. If LCU does not send a signal, or sends an abnormal signal to BCM a predetermined amount of times consecu-tively, system will set LCU in fail-safe condition. During fail-safe condition, all electrical loads controlled by the switch on the questionable LCU will operate in fail-safe mode.

COMPONENT TESTS

Note. Individual component tests are not available at time of publication. For diagnosis, perform diagnostic test related to the faulty component. See DIAGNOSTIC TESTS .

Note. The multiplex control system may be diagnosed using vehicle's on-board diagnostic functions or Nissan CONSULT scan tool.

Verify customer's complaint. Begin LAN communication diagnosis. See DIAGNOSTICS USING INDICATOR LIGHTS or NISSAN CONSULT DIAGNOSTICS . If self-diagnostic results are present, repair as necessary and retest. See DIAGNOSTIC TESTS . If self-diagnostic results are not present, see appropriate article related to malfunctioning system and diagnose by symptom.

Mode I (LAN Communication)

1. This mode checks the communication between the Body Control Module (BCM) and each Local Control Unit (LCU). If a malfunction is detected, self-diagnostic indicator lights (interior dome and step lights) will flash a 2-digit Diagnostic Trouble Code (DTC). See «LAN COMMUNICATION TROUBLE CODES»(ref-32549-S28936409592001101500000) table.
2. To enter on-board diagnostic Mode I, turn ignition off. Set headlight switch and rear window defogger switch in OFF position. Ensure all doors are closed. Set interior light switch in center "O" position.
3. Turn ignition on, then off. Repeatedly press rear window defogger switch to ON position more than 10 times in 10 seconds, ending in the OFF position. Self-diagnostic indicator lights (interior dome and step lights) should illuminate. Turn ignition switch to ON position within 5 seconds after self-diagnostic indicator lights illuminate.
4. Indicator lights should turn off. Self-diagnostic indicator lights should illuminate for 2 seconds and turn off for 2 seconds, indicating successful entry to self-diagnostic Mode I. Self-diagnostic indicator lights will now flash DTCs.
5. The self-diagnostic indicator lights will flash the first digit. After a 1.5-second pause, the second digit will be flashed. (Scheme 7)
6. Record DTCs, and perform appropriate repair procedure. See «DIAGNOSTIC TESTS»(ref-32549-S05198847692001101500000). To exit diagnostic mode, turn ignition off. Diagnostic mode is automatically canceled if left unattended for 10 minutes after DTCs are retrieved. To clear diagnostic codes, turn ignition off and remove fuse No. 56 (7.5-amp) located in fuse and fusible link box.

Scheme 7

LAN COMMUNICATION TROUBLE CODES

Mode II (Switch Signal Monitor)

1. In this mode, BCM and LCUs monitor respective switches in LAN system for input signals. Switch input signals are monitored in the following order. BCM Hood Switch Trunk Compartment Light Switch Trunk Lid Unlock Switch Door Switches (All) Headlight Switch (First Detent) Wiper Switch (INT Function) Wiper Switch (WASH Function) Seat Belt Switch LCU01 Driver Power Window Lock Switch Power Window Main Switches (UP/DOWN) Power Window Automatic Switch Door Lock/Unlock Switch (LOCK/UNLOCK) Door Key Cylinder Switch (LOCK/UNLOCK) Door Unlock Sensor LCU02 Door Key Cylinder Switch (LOCK/UNLOCK) Door Unlock Sensor Passenger Power Window Sub-Switch (UP/DOWN) LCU03 Right Rear Power Window Sub-Switch (UP/DOWN) Door Unlock Sensor LCU04 Left Rear Power Window Sub-Switch (UP/DOWN) Door Unlock Sensor LCU05 Buttons are operated by multi-remote controller. Door Lock Button Door Unlock Button Panic Alarm Button Trunk Lid Opener Button
2. To enter on-board diagnostic Mode II, turn ignition off. Set headlight switch and rear window defogger switch to OFF position. Ensure all doors are closed. Set interior light switch in center "O" position.
3. Turn ignition on, then off. Repeatedly press rear window defogger switch to ON position more than 10 times in 10 seconds, ending in the ON position. Self-diagnostic indicator lights should illuminate. Turn ignition switch to ON position within 5 seconds after indicator lights illuminate.
4. Indicator lights should turn off, and within one second, system should enter on-board diagnostic Mode II. Operate the switches listed above. Indicator lights will illuminate and buzzer will sound each time input signal from a switch is detected. (Scheme 8) To exit diagnostic mode, turn ignition off.

Scheme 8

IVMS Communication Check

1. This mode checks for proper communication function between BCM and each LCU on the In-Vehicle Multiplexing System (IVMS). To perform IVMS communication check, enter IVMS system diagnostics.
2. Select IVMS COMM DIAGNOSIS from CONSULT menu. Record any IVMS related fault messages. Perform appropriate diagnostic test. See «DIAGNOSTIC TESTS»(ref-32549-S05198847692001101500000) . Erase fault message(s) from system memory using Nissan CONSULT.

Wake-Up Mode Diagnostics

1. This mode checks if the respective LCUs are appropriately shifted to wake-up mode when conditions call for such action. To perform wake-up mode diagnostics, select IVMS COMM CHECK, then touch WAKE-UP DIAGNOSIS. Touch START.
2. Touch START again, then turn on switch that is displayed on scan tool. If NO FAILURE is displayed, LCU is okay. Touch NEXT to test next LCU. If a failure is detected, replace appropriate LCU. If scan tool indicates that switch data is unmatched, touch RETEST to repeat sequence.

Note. If self-diagnostics produced multiple DTCs or fault messages, proceed to appropriate diagnostic test that contains the specified multiple faults. See WIRING DIAGRAMS to aid in wire color and wire terminal identification and/or component location.

Only One LCU Malfunctions

Check for faulty harness connections between BCM and LCU in question. Check continuity of data line circuits between LCU in question and harness-to-harness connector. Check ground circuit for LCU in question. Repair as necessary. If no problems are found, replace LCU in question.

All LCUs Malfunction

Check continuity of data line circuits between BCM and harness-to-harness connector. Repair as necessary. If no problems are found, replace BCM.

Check for faulty harness connections between BCM and LCU in question. Check continuity of data line "A" circuit between LCU in question and harness-to-harness connector. Repair as necessary. If no problems are found, replace LCU in question.

Two Or More LCUs Malfunction

Check for faulty harness connections between BCM and LCUs in question. Check continuity of data line "A" circuit for LCUs in question. Repair as necessary. If no problems are found, replace LCUs in question.

Check continuity between ground and data line "A" circuit terminal at BCM. Check for faulty harness connections between BCM and LCUs in question. Check continuity of data line "A" circuit for BCM. Repair as necessary. If no problems are found, replace BCM.

Check for faulty harness connections between BCM and LCU in question. Check continuity of data line "B" circuit between LCU in question and harness-to-harness connector. Repair as necessary. If no problems are found, replace LCU in question.

Check for faulty harness connections between BCM and LCUs in question. Check continuity of data line "B" circuit for LCUs in question. Repair as necessary. If no problems are found, replace LCUs in question.

Check continuity between ground and data line "B" circuit terminal at BCM. Check for faulty harness connections between BCM and LCUs in question. Check continuity of data line "B" circuit for BCM. Repair as necessary. If no problems are found, replace BCM.

Check fuse, fusible link, circuit breaker or related harness. Check for faulty harness connections between BCM and LCU in question. Check continuity of each data line between LCU in question and harness-to-harness connectors. Check ground circuit of LCU in question. Repair as necessary. If no problems are found, replace LCU in question.

Check fuse, fusible link, circuit breaker or related harness. Check for faulty harness connections between BCM and LCUs in question. Check continuity of each data line between LCUs in question and harness-to-harness connectors. Repair as necessary. If no problems are found, replace LCUs in question.

Check continuity between data lines "A" and "B". Check continuity between ground and data line terminals of BCM harness connectors. Check for faulty harness connections between BCM and LCUs in question. Check continuity of each data line circuit between BCM and harness-to-harness connectors. Repair as necessary. If no problems are found, replace BCM.

Repair ground circuit to LCU in question.

Repair ground circuits to LCUs in question.

Replace BCM.