Body Multiplex Communication System - Diagnostics: Diagnosis Toyota Highlander I

HOW TO PROCEED WITH TROUBLESHOOTING

1. Vehicle Brought In
2. Symptom Check
3. Inspect communication function of large-scale body multiplex communication system (Bean) . Check there is no abnormality in the communication system by inspecting the communication function of the body multiplex communication system with hand-held tester. (ECU communication stop, communication line abnormal) With code outputs, proceed to A. (ECU communication stop, communication line abnormal) Without code outputs, proceed to B. A: Go to next step. B: Go to section of each system.
4. Diagnostic Code Check (see «DIAGNOSTIC TROUBLE CODE CHART»(ref-178734-S29021378562005062100000) ) . Check a DTC and note it if a code is output. Delete the DTC. Check if the DTC will be output once again, when the problem symptom is simulated based on the noted code. When no code is output (symptom check and simulation is possible), proceed to A . When no code is output (symptom check and simulation is impossible), proceed to B . When the code is output, proceed to C . Go to next step. Go to Problem Simulation (see «SYMPTOM SIMULATION)»(ref-174461-S27505206962005040500000) . Go to step 7 .
5. Problem Symptoms Table (See «PROBLEM SYMPTOMS»(ref-178734-S01790998692005062100000) ) . Without applicable symptoms, proceed to A . With applicable symptoms, proceed to B . A: Go to next step. B: Go to step 7 .
6. Perform troubleshooting in the following method, depending on malfunction symptom . Pre-check (See «PRE-CHECK»(ref-178734-S22468032122005062100000) ). Terminals of ECU (See «TERMINALS OF ECU»(ref-178734-S05009378802005062100000) ).
7. Adjustment, Repair Or Replacement

End

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1. Multiplex Communication System (Bean) BEAN communication line is used for body, meters and air-conditioning controls. Since the line 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 reasons. In case that the line becomes short (bus-down) for some reasons, however, all the BEAN communication will be impossible and some DTC will be output. NOTE: When bus-down occurs, communication from related ECU will stop. Therefore, outputs of DTC will be impossible, so perform a DTC (SAE code) inspection with hand-held tester.
2. Communication Function Inspection Inspect the battery positive voltage. Standard: 10 - 14 V Perform a diagnosis check of the body ECU by connecting TOYOTA hand-held tester to the DLC3 and turning the ignition switch ON. Check that the DTC of the ECU is unconnected and also a short-circuit in the communication bus is not output.
3. Inspect Output Of Diagnostic By Door Open Indicator . Inspect the battery positive voltage. Standard: 10 - 14 V (When Engine Stopped) Check the DTC output. NOTE: No abnormality exists in all the following items. Check that the door open indicator will be on when any of the doors is opened. NOTE: In case that the indicator will not be on, the following problems are possible reasons; door open indicator LED defective, wire harness short, courtesy light switch's contact condition defective, multiplex network body ECU defective, etc. By using SST (diagnosis check wire), make a short-circuit between terminals TC (13) and CG (4) of the DLC3 connector. SST 09843-18040 NOTE: Do not make a short-circuit in any other positions. Turn the ignition (starter) switch ON and read the number of blinks of the door open indicator. NOTE: When 2 or more codes are output simultaneously, display will be started from the smaller numbered code. When the DTC of the ECU unconnected is displayed, perform an inspection depending on the troubleshooting. NOTE: When the communication bus is defective the door open indicator in the meter will not be on and therefore any DTC will not be output. When other DTC is output, refer to «DIAGNOSTIC TROUBLE CODES»(ref-178734-S29021378562005062100000) and applicable section. When no DTC is output even in the normal condition, problems, such as short-circuit between terminals TC and CG, meter fuses defective etc., may exist. When the door open indicator is always on, wire harness might be short-circuited.
4. Inspect Output Of Diagnosis Trouble Code With Toyota Hand-Held Tester . Battery Voltage Inspection: Standard: 10 - 14 V DTC Monitor Code Output Inspection: Connect hand-held tester to the DLC3 and turn the ignition (starter) switch ON, then check the DTC. NOTE: When DTC check is impossible, check the following items. ECU data monitor is possible (multiplex network body ECU is defective). Display shows communication error (refer to new diagnostic system and operations when an error occurred). (See «SYMPTOM SIMULATION»(ref-174461-S27505206962005040500000) ). When the display shows DTC that the ECU is unconnected and the communication bus is defective, perform an inspection depending on the troubleshooting. NOTE: When other DTC is output, refer to «DIAGNOSTIC TROUBLE CODES»(ref-178734-S29021378562005062100000) and the applicable section.

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1. Body ECU Diagnosis Trouble Code

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1. Multiplex Network Body ECU Check the body ECU. Disconnect the body ECU connectors A (B9) and D (B12). Check the voltage and continuity of each terminal of the vehicle's side connectors. Standard: (Scheme 6) NOTE: If the value is not as specified the vehicle's side may be defective.
2. Power Window Regulator Master Switch Assembly (Door ECU) Check the door ECU. Disconnect the power window master switch assembly connector. Check the voltage and continuity of each terminal of the vehicle's side connector. Standard: (Scheme 8)NOTE: If the value is not as specified the vehicle's side may be defective.
3. Combination Meter Assembly (Meter ECU) Check the meter ECU. Disconnect the meter assembly connector B (C11). Check the voltage and continuity of each terminal of the vehicle's side connectors. Standard: (Scheme 10) NOTE: If the value is not as specified, the vehicle's side may be defective.
4. Air Conditioning Amplifier Assembly Check the air conditioning amplifier. Disconnect the air conditioning amplifier connector B (A10). Check the voltage and continuity of each terminal of the vehicle's side connectors. Standard: (Scheme 12) NOTE: If the value is not as specified, the vehicle's side may be defective.
5. Theft Warning Computer Assembly Check the theft warning ECU. Disconnect the theft warning ECU connector. Check the voltage and continuity of each terminal of the vehicle's side connectors. Standard: (Scheme 14)
6. Engine Control Computer Inspect the ECM operation. Check the voltage and continuity of each terminal of the vehicle's side connectors. NOTE: Inspection should be started from the back side of the connector with the computer connector being connected. Before the measurement, check the power source voltage (10 - 14 V when IG ON) and body ground (5 Ohmsor less between each ground terminal and the engine body, when IG OFF). Standard: (Scheme 16)
7. Sliding Roof Drive Gear Check the sliding roof ECU. Disconnect the sliding roof ECU connector. Check the voltage and continuity of each terminal of the vehicle's side connectors. Standard: (Scheme 18)

PROBLEM SYMPTOMS

1. Troubleshooting For Each Problem Symptom NOTE: Confirm the problem symptom and make an inspection depending on the applicable flow chart. DTC/Problem Symptoms DTC/Problem Symptom Suspect Area «B1211/11»(ref-178734-S18664028812005062100000) No Communication From Driver Door ECU For More Than 10 Seconds ..... Power Window Regulator Master Switch Assembly ..... Wire Harness «B1214»(ref-178734-S35353180072005062100000) Short In Communication Circuit And +B Power Source System ..... Power Window Regulator Master Switch Assembly ..... ECM ..... Air Conditioning Amplifier Assembly ..... Combination Meter Assembly ..... Theft Warning ECU ..... Sliding Roof Drive Gear ..... Network Gateway ECU ..... Wire Harness ..... MPX Body ECU «B1215»(ref-178734-S35353180072005062100000) Short In Communication Circuit And +B Power Source System ..... Power Window Regulator Master Switch Assembly ..... ECM ..... Air Conditioning Amplifier Assembly ..... Combination Meter Assembly ..... Theft Warning ECU ..... Sliding Roof Drive Gear ..... Network Gateway ECU ..... Wire Harness ..... MPX Body ECU «B1261»(ref-178734-S32154736842005062100000) No Communication From ECM For More Than 10 Seconds ..... ECM ..... Wire Harness «B1262/62»(ref-178734-S39124909962005062100000) No Communication From A/C ECU For More Than 10 Seconds ..... Air Conditioning Amplifier Assembly ..... Wire Harness «B1269/69»(ref-178734-S34391054772005062100000) No Communication From Theft Deterrent ECU For More Than 10 Seconds ..... Theft Warning ECU ..... Wire Harness «B1271»(ref-178734-S35641895442005062100000) No Communication From Combination Meter ECU For More Than 10 Seconds ..... Combination Meter Assembly .......... Wire Harness «B1273/73»(ref-178734-S05585596202005062100000) No Communication From Sliding Roof Control ECU For More Than 10 Seconds ..... Sliding Roof Drive Gear ..... Wire Harness

Circuit Description

B1211/11 will be output when the communication between the power window master switch and MPX body ECU stops for more than 10 seconds.

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Note. For complete multiplex system wiring diagram, see COMPUTER DATA LINES .

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1. Check continuity of communication line. Check the wire harness among MPX body ECU and power window master switch and air conditioning amplifier. Disconnect the connectors of the power window master switch, MPX body ECU and air conditioning amplifier. Check the continuity between terminal 8 (MPX2) of the power window master switch vehicle's side connector and terminal B9-10 (MPX2) of the MPX body ECU vehicle's side connector. Standard: Continuity Check the continuity between terminal 7 (MPX1) of the power window master switch vehicle's side connector and terminal A11-2 (MPX+) of the air conditioner amplifier vehicle's side connector. Standard: Continuity OK: Go to next step. NG: Repair or replace harness and connector.
2. Check power window regulator master switch assy. Inspect the power window master switch (power source input). Disconnect the power window master switch connector. Check the voltage between each terminal of the power window master switch vehicle's side connector. Standard: (Scheme 23)OK: Go to next step. NG: Repair or replace fuse or wire harness and connector.
3. Check power window regulator master switch assy. Inspect the power window master switch (GND). Disconnect the power window master switch connector. Check the continuity between terminal 2 (GND) of the power window master switch and the body ground. Standard: Continuity OK: Replace power window regulator master switch assy. NG: Repair or replace harness and connector.

B1214 and B1215 will be output when +B and body ground is short-circuited on the communication bus. Detecting this condition will make all the BEAN communication unable and output some DTCs.

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These DTC notify how the switch works as follows

If the DTC is not output when operating the switch, switch contact has failed. If the DTC is output when not operating the switch, it means the switch is ON or stuck. When something wrong is found by this diagnosis, inspect each switch. Replace the switch if there is a problem or check the body ECU and wire harness.

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Note. Please refer to the pages listed below for switch inspection.

1. For the driver seat belt buckle switch, see «SEAT BELT WARNING LAMP AND BUZZER FOR DRIVER'S SEAT DOES NOT OPERATE»(ref-190892-S25353153392005091700000) .
2. For the light control switch, see «INSPECTION»(ref-191031-S06997559152005092000000) .

B1261 will be output when the communication between the ECM and MPX body ECU stops for more than 10 seconds.

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B1262/62 will be output when the communication between the air conditioning amplifier and MPX body ECU stops for more than 10 seconds.

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B1269/69 will be output when the communication between the theft warning ECU and MPX body ECU stops for more than 10 seconds.

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B1271 will be output when the communication between meter ECU and MPX body ECU stops for more than 10 seconds.

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B1273/73 will be output when the communication between the sliding roof ECU and the MPX body ECU stops for more than 10 seconds.

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