Power Source/wiring: Diagnosis Lexus LS IV

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use these procedures to troubleshoot the electric power control system.
2. *: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP
2. INSPECT BATTERY VOLTAGE Standard voltage: 11 to 14 V If the voltage is below 11V, recharge or replace the battery before proceeding.
3. INSPECT COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM* Using the Techstream, check if the CAN communication system is functioning normally. Result RESULT REFERENCE CHART Result Proceed to CAN DTC is not output A CAN DTC is output B B: Go to «CAN COMMUNICATION SYSTEM»(ref-349742-S22957258702009120800000) A: Go to next step
4. CHECK DATA LIST/ACTIVE TEST* Check the Data List's load control history (number of items) and the final load control history*. Then write down the information. HINT: Refer to the following description for information about "final load control history".
5. CHECK FOR DTC* Check for DTCs and write them down. Delete the DTC. Check for DTC again. Result RESULT REFERENCE CHART Result Proceed to No DTCs, symptom confirmation and symptom simulation can be performed A No DTCs, symptom confirmation and symptom simulation cannot be performed B DTC output C B: Go to INTRODUCTION (see «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-349706-S05264741182009120800000) ) C: Go to step 8 A: Go to next step
6. PROBLEM SYMPTOMS TABLE Result RESULT REFERENCE CHART Result Proceed to Fault is not listed in problem symptoms table A Fault is listed in problem symptoms table B B: Go to step 8 A: Go to next step
7. OVERALL ANALYSIS AND TROUBLESHOOTING* Data List/Active Test (see «DATA LIST/ACTIVE TEST»(ref-349751-S06341509852009120800000) ) Terminals of ECU (see «TERMINALS OF ECU»(ref-349751-S11013332682009120800000) )
8. ADJUST, REPAIR OR REPLACE
9. CONFIRMATION TEST NEXT: END

PROBLEM SYMPTOMS TABLE

HINT

1. Use the table below to help determine the cases of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in order they are listed. Replace parts as necessary.
2. Inspect the fuses and relays related to this system before inspecting the suspected areas below. Electric power control system PROBLEM SYMPTOMS CHART Symptom Suspected Area See Indicator and charge warning light illuminate Battery - Generator «INSPECTION»(ref-349732-S38853849562009120800000) Charging system «ON-VEHICLE INSPECTION»(ref-349732-S35552932422009120800000) Indicator and each systems indicator illuminate Battery - Generator «INSPECTION»(ref-349732-S38853849562009120800000) Charging system «ON-VEHICLE INSPECTION»(ref-349732-S35552932422009120800000) Each system - Load control linked component does not operate Check load control history «OPERATION CHECK»(ref-349751-S29657962842009120800000) Each system - Power cut linked part does not operate Each system

Scheme 25

1. CHECK ELECTRIC POWER CONTROL ECU (PASSENGER SIDE JUNCTION BLOCK) Disconnect the PA, PM, PK and A69 ECU connectors. Measure the resistance and voltage according to the value(s) in the table below. VOLTAGE AND RESISTANCE REFERENCE CHART Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition PA-39 (GND) - Body ground W-B - Body ground Ground Always Below 1 ohms A69-8 (VB-) - Body ground W-B - Body ground Voltage detection (-) Always Below 1 ohms PM-1 (BECU) - Body ground L - Body ground ECU power supply Always 11 to 14 V PM-1 (BCUT) - Body ground L - Body ground Power cut linked power (input) Always 11 to 14 V A69-18 (VB+) - Body ground BE - Body ground Voltage detection (+) Always 11 to 14 V PK-1 (IG) - Body ground G - Body ground IG power supply Engine switch on (IG) 11 to 14 V If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the PA, PM, PK and A69 ECU connectors. Measure the voltage and resistance according to the value(s) in the table below. VOLTAGE AND RESISTANCE REFERENCE CHART Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition A69-12 (STSW) - PA-39 (GND) B - W-B Starter switch signal Engine switch on (IG) --> Engine cranking Below 1 V --> 8 to 14 V A69-6 (VC) - PA-39 (GND) B - W-B Sensor power supply Engine switch on (IG) 4.5 to 5.5 V A69-9 (IB) - PA-39 (GND) L - W-B Battery current detection Engine switch on (IG) 0.5 to 4.5 V A69-10 (E2) - PA-39 (GND) W - W-B Sensor ground Engine switch on (IG) Below 1 ohms A69-20 (THB) - PA-39 (GND) P - W-B Battery temperature detection Engine switch on (IG) 0.5 to 4.5 V PA-57 (CUTD) - PA-39 (GND) PA-35 (CUTD) - PA-39 (GND) B - W-B B - W-B Power cut linked power (output) Engine switch on (IG) 11 to 14 V If the result is not as specified, the ECU may have a malfunction.

DTC CHECK/CLEAR

1. CHECK DTC Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical/Electric Power Control/Trouble Codes. Read the DTCs.
2. CLEAR DTC Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the tester on. Enter the following menus: Body Electrical/Electric Power Control/Trouble Codes. Erase the DTCs.

DATA LIST/ACTIVE TEST

1. DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensor, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time. NOTE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. Warm up the engine. Turn the engine switch off. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical/Electric Power Control/Data List. According to the display on the Techstream, read the "Data List". Electric Power Control ELECTRIC POWER CONTROL REFERENCE CHART Tester Display Measurement Item/Range Normal Condition Diagnostic Note Electrical Charge Current Current battery current value display/ Min.: -300, Max.: 100 [A] Amperage value is displayed - Battery Temperature Current battery temperature value display/ Min.: -30, Max.: 90 [°C] Temperature near battery is displayed - Battery Voltage Current battery voltage value display/ Min.: 0, Max.: 16.67 [V] Battery voltage is displayed - Power Cut Signal Condition of relay (which cuts part of vehicle's power) display/ ON or OFF ON: Power supply supplied OFF: Power supply cut - Battery Voltage Low Battery voltage drop judgment display/ ON or OFF ON: Dropped OFF: Normal Meter display is shown Control Load Level 3 Electrical equipment operation limit display/ ON or OFF ON: During electrical equipment operation limit OFF: No electrical equipment operation limit Meter display is shown Voltage Detection Battery voltage detection path malfunction display/ ON or OFF ON: Malfunctioning OFF: Normal Meter display is shown Alternator Failure Display for generator malfunction or charging line malfunction/ ON or OFF ON: Malfunctioning OFF: Normal Meter display is shown Control Load Level Current load control level display/ 0 to 3 0: No control 1: Load control level 1 3: Load control level 3 Load control level 2 is not displayed Request to Limit EPS EPS current consumption limit request display/ 0 to 1 0: No request is made 1: Request is made - Req Limit Air Suspension Air suspension current consumption limit request display/ ON or OFF ON: No request is made OFF: Request is made - Ctrl Load Lv1 History Load control level 1 history count/ 0 to 255 History count until now - Ctrl Load Lv3 History Load control level 3 history count/ 0 to 255 History count until now - Req Ctrl Load on Fail Hist Load control operation history display (when charging system is malfunctioning)/ ON or OFF ON: Operation history is present OFF: No operation history - Req Ctrl Load on EPS Hist Load control operation history display (during EPS operation)/ ON or OFF ON: Operation history is present OFF: No operation history - Req Ctrl Load on PCS Hist Load control operation history display (during PCS operation)/ ON or OFF ON: Operation history is present OFF: No operation history - Req Ctrl Load Hist 3 Load control operation history display (when battery voltage is low)/ ON or OFF ON: Operation history is present OFF: No operation history - Req Ctrl Load Hist 2 Load control operation history display (when battery voltage is low)/ ON or OFF ON: Operation history is present OFF: No operation history - Req CM Load Hist 1 Load control operation history display (when battery voltage is low)/ ON or OFF ON: Operation history is present OFF: No operation history - Hist-Bat Vol for Ctrl Load Battery voltage value display (when load control is performed)/ Min.: 0, Max.: 16.67 [V] Battery voltage value when load control is performed is displayed - Hist-Bat Cur for Ctrl Load Battery current value display (when load control is performed)/ Min.: -300, Max.: 100 [A] Battery current value when load control is performed is displayed - Bat Temp Hist Battery temperature value display (when load control is performed)/ Min.:-150, Max.: 150 [°C] Battery temperature value when load control is performed is displayed - Virtual Opn Circuit Vol Hist Battery virtual open-circuit voltage value display (when load control is performed)/ Min.: 0, Max.: 16.67 [V] Battery virtual open-circuit voltage value when load control is performed is displayed - Internal Resistance Hist Battery interior resistance value display (when load control is performed)/ Min.: 0, Max.: 120 [mohms] Battery interior resistance value when load control is performed is displayed - # Codes Number of trouble code
2. ACTIVE TEST HINT: Using the Techstream to perform the Active Tests allows relays, VSVs and actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests. Warm up the engine. Turn the engine switch off. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical/Electric Power Control/Active Test. According to the display on the Techstream, perform the "Active Test". Electric Power Control ELECTRIC POWER CONTROL REFERENCE CHART Tester Display Test Part Control Range Activate Power Cut Relay When OFF, power cut linked parts cannot be used ON/OFF Limit Load Level Limit control is performed on heater related load control linked systems 0/1/3 Request to Limit EPS Limit control is performed on current for EPS assist ON/OFF Request to Limit Air Suspension Limit control is performed on air suspension compressor operation ON/OFF

DIAGNOSTIC TROUBLE CODE CHART

HINT

1. If a trouble code is displayed during the DTC check, inspect the trouble areas listed for that code. For details of the code, refer to the "DTC Code" below.
2. Inspect the fuses and relays related to this system before inspecting the trouble areas below. ELECTRIC POWER CONTROL ECU [Electric Power Control] ELECTRIC POWER CONTROL ECU REFERENCE CHART DTC Code Detection Item Trouble Area «B22A0»(ref-349751-S36810355842009120800000) IG2 Terminal Circuit Low P IG2 fuse P-J/B fuse Engine room No. 2 junction block, relay block Passenger side junction block (Electric power control ECU) Wire harness «B22A1»(ref-349751-S03008491392009120800000) Battery Current Sensor Battery current sensor Passenger side junction block (Electric power control ECU) Wire harness «B22A6»(ref-349751-S29194060662009120800000) THB Terminal Voltage Low Battery current sensor Passenger side junction block (Electric power control ECU) Wire harness «B22A8»(ref-349751-S34327838652009120800000) VB Terminal Voltage VSSR fuse Passenger side junction block (Electric power control ECU) Wire harness «B22AB»(ref-349751-S33637762772009120800000) Open in Starter Switch Terminal Passenger side junction block (Electric power control ECU) Wire harness «B22AC»(ref-349751-S06081576272009120800000) Alternater Stop Power Generation Generator SFI system «B22AD»(ref-349751-S06081576272009120800000) No Control for Power Generation of Alternator Generator SFI system «B22AE»(ref-349751-S20655729962009120800000) Open in Alternater Charge Line Generator Wire harness «B22B2»(ref-349751-S23201215992009120800000) Power Cut Relay On Stuck P-D/C CUT fuse Passenger side junction block (Electric power control ECU) Wire harness «B22B3»(ref-349751-S23201215992009120800000) Power Cut Relay Off Stuck P-D/C CUT fuse Passenger side junction block (Electric power control ECU) Wire harness «B22B6»(ref-349751-S39687082152009120800000) Communication Error with ECM/PCM "A" (Generate Voltage Data of Alternator) CAN communication system ECM «B22B7»(ref-349751-S39687082152009120800000) Communication Error with ECM/PCM "A" (Generate Rate Data of Alternator) CAN communication system ECM «B22B8»(ref-349751-S39687082152009120800000) Communication Error with ECM/PCM "A" (Charge Mode Data) CAN communication system ECM «B22BA»(ref-349751-S39687082152009120800000) Communication Error with ECM/PCM "A" (Engine Speed Data) CAN communication system ECM «B22BB»(ref-349751-S31056477642009120800000) Communication Error with Brake System Control Module (Vehicle Speed Data) CAN communication system Skid control ECU «B22BC»(ref-349751-S39687082152009120800000) Communication Error with ECM/PCM "A" (Intake-Air Temperature Data) CAN communication system ECM «B22BD»(ref-349751-S39687082152009120800000) Communication Error with ECM/PCM "A" (Coolant Temperature Data) CAN communication system ECM «U0100»(ref-349751-S21712620862009120800000) Lost Communication with ECM/ PCM "A" CAN communication system Passenger side junction block (Electric power control ECU) «U0129»(ref-349751-S21712620862009120800000) Lost Communication with Brake System Control Module CAN communication system Passenger side junction block (Electric power control ECU) «U0131»(ref-349751-S21712620862009120800000) Lost Communication with Power Steering Control Module CAN communication system Passenger side junction block (Electric power control ECU) «U0142»(ref-349751-S21712620862009120800000) Lost Communication with Gateway "A" CAN communication system Passenger side junction block (Electric power control ECU) «U0164»(ref-349751-S21712620862009120800000) Lost Communication with HVAC Control Module CAN communication system Passenger side junction block (Electric power control ECU) «U1104»(ref-349751-S21712620862009120800000) Lost Communication with Driving Support ECU CAN communication system Passenger side junction block (Electric power control ECU) «U1111»(ref-349751-S21712620862009120800000) Lost Communication with Front Controller Module CAN communication system Passenger side junction block (Electric power control ECU)

INSPECTION PROCEDURE

1. CHECK GENERATOR ASSEMBLY Check the generator (see «GENERATOR»(ref-349732-S33961771122009120800000) ). OK: Charging system is normal. NG: REPLACE GENERATOR ASSEMBLY (See «REMOVAL»(ref-349732-S04425564642009120800000) ) OK: GO TO SFI SYSTEM (See «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-349724-S18283209912009120800000) )

1. CHECK FOR DTC (CAN COMMUNICATION SYSTEM) Check for DTCs related to the CAN communication system (see «DIAGNOSIS SYSTEM»(ref-349742-S42827894432009120800000) ). OK: DTC is not output. NG: GO TO CAN COMMUNICATION SYSTEM (See «CAN COMMUNICATION SYSTEM»(ref-349742-S22957258702009120800000) ) OK: Go to next step
2. CHECK FOR DTC Delete the DTC (see «DTC CHECK/CLEAR»(ref-349751-S04666554822009120800000) ). Check for the DTC again (see «DTC CHECK/CLEAR»(ref-349751-S04666554822009120800000) ). OK: DTC is not output. NG: REPLACE ECM (See «REMOVAL»(ref-349724-S01517209942009120800000) ) OK: END

1. CHECK FOR DTC (CAN COMMUNICATION SYSTEM) Check for DTCs related to the CAN communication system (see «DIAGNOSIS SYSTEM»(ref-349742-S42827894432009120800000) ). OK: DTC is not output. NG: GO TO CAN COMMUNICATION SYSTEM (See «CAN COMMUNICATION SYSTEM»(ref-349742-S22957258702009120800000) ) OK: Go to next step
2. CHECK FOR DTC Delete the DTC (see «DTC CHECK/CLEAR»(ref-349751-S04666554822009120800000) ). Check for the DTC again (see «DTC CHECK/CLEAR»(ref-349751-S04666554822009120800000) ). OK: DTC is not output. NG: REPLACE SKID CONTROL ECU ASSEMBLY (See «REMOVAL»(ref-349740-S33717864392009120800000) ) OK: END

1. CHECK FOR DTC (CAN COMMUNICATION SYSTEM) Check for DTCs related to the CAN communication system (see «DIAGNOSIS SYSTEM»(ref-349742-S42827894432009120800000) ). OK: DTC is not output. NG: GO TO CAN COMMUNICATION SYSTEM (See «CAN COMMUNICATION SYSTEM»(ref-349742-S22957258702009120800000) ) OK: END

Scheme 26

Scheme 27

1. REMOVE COWL TOP VENTILATOR LOUVER RH (See «REMOVAL»(ref-349732-S04425564642009120800000) )
2. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to prevent airbag and seat belt pretensioner activation. NOTE: After the engine switch is turned off, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the engine switch off, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.
3. REMOVE ENGINE ROOM SIDE COVER RH (See «REMOVAL»(ref-349714-S31912998822009120800000) )
4. REMOVE FRONT FENDER PROTECTOR UPPER RH (See «REMOVAL»(ref-349735-S07548571092009120800000) )
5. REMOVE BATTERY CURRENT SENSOR Disconnect the connector from the battery current sensor assembly. Remove the bolt, ground terminal and battery current sensor assembly. Remove the battery current sensor assembly from the ground terminal.

Scheme 28

1. INSPECT BATTERY CURRENT SENSOR Measure the resistance according to the value (s) in the table below. Standard resistance STANDARD RESISTANCE REFERENCE CHART Tester Connection Specified Condition Tester (+) --> 2 (VC) Tester (-) --> 4 (E2) 3 k to 10 kohms Tester (+) --> 2 (VC) Tester (-) --> 3 (IB) 0.5 kohms or less Tester (+) --> 3 (IB) Tester (-) --> 4 (E2) 3 k to 10 kohms Measure the resistance according to the value (s) in the table below. Standard resistance STANDARD RESISTANCE REFERENCE CHART Tester Connection Condition Specified Condition 1 (THB) - 4 (E2) 20 to 30°C (68 to 86°F) 1.5 k to 2.5 kohms (0 to 70°C (32 to 158°F)) (0.3 k to 6.0 kohms) NOTE: The temperature shown in the condition is for the area surrounding the sensor, not the sensor itself.

Scheme 29

1. INSTALL BATTERY CURRENT SENSOR Insert the hook of the ground terminal through the battery current sensor's hole. Then attach the hook to the parts labeled A of the bracket. Hook the bracket onto the hole on the engine room body, and install the battery current sensor assembly with the bolt. Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf) Connect the connector to the battery current sensor assembly.
2. INSTALL FRONT FENDER PROTECTOR UPPER RH (See «INSTALLATION»(ref-349735-S39879645972009120800000) )
3. INSTALL ENGINE ROOM SIDE COVER RH (See «INSTALLATION»(ref-349714-S23488176532009120800000) )
4. CONNECT CABLE TO NEGATIVE BATTERY TERMINAL
5. INSTALL COWL TOP VENTILATOR LOUVER RH (See «INSTALLATION»(ref-349732-S09051375432009120800000) )
6. PERFORM INITIALIZATION Perform initialization (see «INITIALIZATION»(ref-349706-S07943075812009120800000) ). NOTE: Certain systems need to be initialized after disconnecting and reconnecting the cable from the negative (-) battery terminal.