Contents Wiring diagrams Section: Communication Devices All sections

Multiplex Communication System: Other Lexus ES XV30

Communication Devices 2 illustrations ~618 words

BODY ELECTRONICS AREA NETWORK (BEAN)

The BEAN consists of 2 different systems: One system is a loop-shaped circuit where the driver door ECU and front passenger door ECU are united with the body ECU in the center of the line. Since the line for both front door ECUs is loop-shaped, the communication can be kept by the line that is not open even if a part of the line becomes open for some reason. In case the line becomes shorted to ground or shorted to power for some reason, communication between the body ECU and the front door ECUs will be impossible and DTCs B1214 or B1215 will be output.

The second is a system where the body ECU and theft deterrent ECU are connected alone through a single communication line. In case the line becomes shorted to ground or shorted to power for some reason, communication between the body ECU and the theft deterrent ECU will not be impossible. DTC B1269 is output if communication between the body ECU and theft deterrent ECU is lost.

Diagnostic trouble codes are output if a fault is detected in the communication circuit between the body ECU and driver door ECU, front passenger door ECU and/or theft deterrent ECU.

LOCAL AREA NETWORK (LAN)

The LAN is a communication circuit between the body ECU, left rear door ECU and right rear door ECU. Diagnostic trouble codes are not output if a fault is detected in the communication circuit between the body ECU and either rear door ECU. Faults in this system can be identified through symptom diagnosis.

Scheme 13

Scheme 13: LOCAL AREA NETWORK (LAN)

PRE-CHECK

Note. Before performing pre-check, ensure battery voltage is 10-14 volts. Replace battery and/or repair power feed circuits as necessary.

Pre-check confirms that the diagnostic system is functional and able to identify faults in the system. Two components must be checked to ensure diagnostic system is functional: Body ECU and OPEN DOOR indicator light. Test the body ECU first, then the OPEN DOOR indicator light.

Body ECU

Operate luggage compartment door opener system. If luggage compartment door opener system operates properly, test OPEN DOOR indicator light. See OPEN DOOR INDICATOR LIGHT . If luggage compartment door opener system does not operate properly, diagnose and repair luggage compartment door opener system components. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR RELEASE article under DOOR LOCKS & ANTI-THEFT SYSTEMS in ACCESSORIES & EQUIPMENT.

OPEN DOOR Indicator Light

Ensure OPEN DOOR indicator light illuminates when any door is opened. If indicator operates properly, proceed to RETRIEVING DIAGNOSTIC TROUBLE CODES . If indicator does not operate properly, diagnose and repair OPEN DOOR indicator light. See INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.

PIN VOLTAGE TESTS

Note. Ensure battery voltage is a minimum of 10-14 volts before beginning pin voltage check on driver side junction block.

DRIVER SIDE JUNCTION BLOCK

Junction blocks are used to pass electrical signals from one harness to another harness and/or from one terminal to another on the same harness. Junction blocks provide a convenient point to isolate individual harnesses and circuits for diagnosis to locate circuits that may open or shorted.

To test driver side junction block, turn ignition off and gain access to junction block. See DRIVER SIDE JUNCTION BLOCK under REMOVAL & INSTALLATION. Disconnect connectors 2A, 2D, 2G, 2H and 2K from driver side junction block. (Scheme 14) Backprobing, check voltage and/or continuity between identified connectors and terminals as specified. See DRIVER SIDE JUNCTION BLOCK PIN VOLTAGE CHART table.

Connector/Terminal (Wire Color) (1)CircuitConditionSpecification
2A/12 (White/Black) To Body GroundSignal Ground (SGND)ConstantContinuity
2D/3 (White/Black) To Body GroundGround (GND)ConstantContinuity
2G/14 (Red/Black) To 2D/3 (White/Black)Power From 25-Amp DOOR1 Fuse (BDR1)Constant10-14 Volts
2H/2 (Red/Black) To 2D/3 (White/Black)Power From 25-Amp DOOR2 Fuse (BDR2)Constant10-14 Volts
2K/11 (White/Blue) To 2D/3 (White/Black)Power From 10-Amp ECU-B Fuse (B)Constant10-14 Volts
(1) (Scheme 14)to identify driver side junction block connectors and terminals.
(1)(Scheme 14)to identify driver side junction block connectors and terminals.

DRIVER SIDE JUNCTION BLOCK PIN VOLTAGE CHART

Scheme 14

Scheme 14

Body control ECU is attached to driver side junction block under left side of instrument panel. see scheme 2 Removal and installation procedures are not available from manufacturer.