Climate Control Seat (Diagnostics): Diagnosis Lexus HS I

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use this procedure to troubleshoot the climate control seat system.
2. The Techstream should be used in step 4.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. CUSTOMER PROBLEM ANALYSIS CHECK AND SYMPTOM CHECK NEXT: Go to next step
3. PROBLEM SYMPTOMS TABLE HINT: NEXT: Go to next step
4. OVERALL ANALYSIS AND TROUBLESHOOTING Circuit inspection Terminals of ECU HINT: NEXT: Go to next step
5. ADJUST, REPAIR OR REPLACE NEXT --> END

PROBLEM SYMPTOMS TABLE

HINT

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptoms by checking the suspected areas in the order they are listed. Replace parts as necessary.

CLIMATE CONTROL SYSTEM

Scheme 96

Scheme 97

1. A/C AMPLIFIER ASSEMBLY Disconnect the F47 connector. Measure the voltage and resistance according to the value(s) in the table below. HINT: Measure the values on the wire harness side with the connector disconnected. Tester Connection Wiring Color Terminal Description Condition Specified Condition F47-21 (B) - Body ground GR - Body ground A/C amplifier power supply Power switch off 11 to 14 V F47-1 (IG+) - Body ground W - Body ground A/C amplifier power supply Power switch on (IG) 11 to 14 V F47-14 (GND) - Body ground W-B - Body ground A/C amplifier ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the F47 connector. Measure the voltage and resistance according to the value(s) in the table below. Tester Connection Wiring Color Terminal Description Condition Specified Condition F48-7 (SG-6) - Body ground V - Body ground Seat heater switch volume ground Always Below 1 ohms F48-8 (S5-2) - Body ground R - Body ground Seat heater switch volume power source Power switch on (IG) 4.5 to 5.5 V F48-4 (SVDS) - Body ground BR - Body ground Seat heater switch volume signal Seat heater switch volume between 0 and 3 0 to 5 V F48-17 (SVPS) - Body ground BR - Body ground Seat heater switch volume signal Seat heater switch volume between 0 and 3 0 to 5 V F48-10 (SVPB) - Body ground B - Body ground Climate control blower control signal Power switch on (IG), climate control switch on Pulse generation (See waveform (Scheme 97) ) F48-9 (SVDB) - Body ground B - Body ground Climate control blower control signal Power switch on (IG), climate control switch on Pulse generation (See waveform (Scheme 97) ) If the result is not as specified, the ECU may have a malfunction. Waveform (Reference): Using an oscilloscope: Tester Connection F48-10 (SVPB) - Body ground F48-9 (SVDB) - Body ground Tool Setting 2 V/DIV., 500 μsec/DIV. Vehicle Condition Power switch on (IG)

ON-VEHICLE INSPECTION

1. CHECK SEATBACK CLIMATE CONTROL BLOWER LH Turn the power switch on (IG). Set the seat heater switch blower side volume to level 3 (maximum). Check that the fan motor turns smoothly.
2. CHECK SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH Turn the power switch on (IG). Set the seat heater switch blower side volume to level 3 (maximum). Check that the fan motor turns smoothly.
3. CHECK SEATBACK CLIMATE CONTROL BLOWER RH Turn the power switch on (IG). Set the seat heater switch blower side volume to level 3 (maximum). Check that the fan motor turns smoothly.
4. CHECK SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY RH Turn the power switch on (IG). Set the seat heater switch blower side volume to level 3 (maximum). Check that the fan motor turns smoothly.

INSPECTION PROCEDURE

Note. Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

1. SYSTEM CHECK Check the climate control seat operation. Result Result Proceed to Climate control seat does not operate (Front LH) A Climate control seat does not operate (Front RH) B Both climate control seats do not operate C C --> See step 18 B --> See step 10 A: Go to next step
2. SYSTEM CHECK Check the climate control operation again. Result Result Proceed to Only seat back climate control blower LH does not operate A Both climate control blowers do not operate B B --> See step 5 A: Go to next step
3. CHECK HARNESS AND CONNECTOR (SEAT BACK BLOWER POWER SUPPLY) Disconnect the T13 connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition T13-2 (IG) - T13-1 (GND) Power switch on (IG) Blower switch ON (Vol: 1 to 3) 6.7 to 9.3 V NG --> See step 4 OK --> See step 20
4. CHECK HARNESS AND CONNECTOR (SEAT CUSHION BLOWER - SEAT BACK BLOWER) Disconnect the T12 connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition T13-2 (IG) - T12-2 (CTB) Always Below 1 ohms T13-2 (IG) - Body ground Always 10 kohms or higher T13-1 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 21
5. CHECK HARNESS AND CONNECTOR (SEAT CUSHION BLOWER POWER SUPPLY) Disconnect the T12 connector. Measure the voltage and resistance according to the value(s) in the table below. Standard Voltage and Resistance Tester Connection Condition Specified Condition T12-1 (IG) - Body ground Power switch on (IG) 11 to 14 V T12-4 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
6. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY Reconnect the T12 connector. Check the input signal waveform. Connect an oscilloscope to terminal 3 and body ground with the seat cushion climate control blower assembly LH connector still connected. Check the signal waveform according to the condition(s) in the table below. Terminal No. T12-3 (SIGN) - Body ground Tool Setting 2 V/DIV., 500 μsec./DIV. Vehicle Condition Power switch on (IG), seat heater switch ON TEXT IN ILLUSTRATION *1 Component with harness connected (Seat Cushion Climate Control Blower Assembly LH) NG --> See step 7 OK --> See step 22
7. CHECK HARNESS AND CONNECTOR (SEAT CUSHION BLOWER - A/C AMPLIFIER) Disconnect the T12 and F48 connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition T12-3 (SIGN) - F48-9 (SVDB) Always Below 1 ohms T12-3 (SIGN) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
8. INSPECT SEAT HEATER SWITCH Remove the seat heater switch. Refer to «REMOVAL»(ref-398249-S34920053172011051600000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F22-8 (SVS5) - F22-10 (SVSG) Always 1.54 to 2.86 kohms F22-7 (BLLH) - F22-10 (SVSG) Blower switch OFF 1.54 to 2.86 kohms F22-7 (BLLH) - F22-10 (SVSG) Blower switch ON (Vol: 3) Below 100 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Seat Heater Switch) NG --> See step 23 OK: Go to next step
9. CHECK HARNESS AND CONNECTOR (SEAT HEATER SWITCH - A/C AMPLIFIER) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F22-7 (BLLH) - F48-4 (SVDS) Always Below 1 ohms F22-8 (SVS5) - F48-8 (S5-2) Always Below 1 ohms F22-10 (SVSG) - F48-7 (SG-6) Always Below 1 ohms F22-7 (BLLH) - Body ground Always 10 kohms or higher F22-8 (SVS5) - Body ground Always 10 kohms or higher F22-10 (SVSG) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 24
10. SYSTEM CHECK Check the climate control operation again. Result Result Proceed to Only seat back climate control blower RH does not operate A Both climate control blowers do not operate B B --> See step 13 A: Go to next step
11. CHECK HARNESS AND CONNECTOR (SEAT BACK BLOWER POWER SUPPLY) Disconnect the S8 connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition S8-2 (IG) - S8-1 (GND) Power switch on (IG) Blower switch ON (Vol: 1 to 3) 6.7 to 9.3 V NG --> See step 12 OK --> See step 25
12. CHECK HARNESS AND CONNECTOR (SEAT BACK BLOWER - SEAT CUSHION BLOWER) Disconnect the S7 connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition S8-2 (IG) - S7-2 (CTB) Always Below 1 ohms S8-2 (IG) - Body ground Always 10 kohms or higher S8-1 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 26
13. CHECK HARNESS AND CONNECTOR (SEAT CUSHION BLOWER POWER SUPPLY) Disconnect the S7 connector. Measure the voltage and resistance according to the value(s) in the table below. Standard Voltage and Resistance Tester Connection Condition Specified Condition S7-1 (IG) - Body ground Power switch on (IG) 11 to 14 V S7-4 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
14. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY Reconnect the S7 connector. Check the input signal waveform. Connect an oscilloscope to terminal 3 and body ground with the climate control blower assembly RH connector still connected. Check the signal waveform according to the condition(s) in the table below. Terminal No. S7-3 (SIGN) - Body ground Tool Setting 2 V/DIV., 500 μsec./DIV. Vehicle Condition Power switch on (IG), seat heater switch ON TEXT IN ILLUSTRATION *1 Component with harness connected (Seat Cushion Climate Control Blower Assembly RH) NG --> See step 15 OK --> See step 27
15. CHECK HARNESS AND CONNECTOR (SEAT CUSHION BLOWER - A/C AMPLIFIER) Disconnect the S7 and F48 connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition S7-3 (SIGN) - F48-10 (SVPB) Always Below 1 ohms S7-3 (SIGN) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
16. INSPECT SEAT HEATER SWITCH Remove the seat heater switch. Refer to «REMOVAL»(ref-398249-S34920053172011051600000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F22-8 (SVS5) - F22-10 (SVSG) Always 1.54 to 2.86 kohms F22-9 (BLRH) - F22-10 (SVSG) Blower switch OFF 1.54 to 2.86 kohms F22-9 (BLRH) - F22-10 (SVSG) Blower switch ON (Vol: 3) Below 100 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Seat Heater Switch) NG --> See step 28 OK: Go to next step
17. CHECK HARNESS AND CONNECTOR (SEAT HEATER SWITCH - A/C AMPLIFIER) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F22-9 (BLRH) - F48-17 (SVPS) Always Below 1 ohms F22-8 (SVS5) - F48-8 (S5-2) Always Below 1 ohms F22-10 (SVSG) - F48-7 (SG-6) Always Below 1 ohms F22-12 (E) - Body ground Always Below 1 ohms F22-9 (BLRH) - Body ground Always 10 kohms or higher F22-8 (SVS5) - Body ground Always 10 kohms or higher F22-10 (SVSG) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 29
18. INSPECT SEAT HEATER SWITCH Remove the seat heater switch. Refer to «REMOVAL»(ref-398249-S34920053172011051600000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F22-8 (SVS5) - F22-10 (SVSG) Always 1.54 to 2.86 kohms F22-7 (BLLH) - F22-10 (SVSG) Blower switch OFF 1.54 to 2.86 kohms F22-7 (BLLH) - F22-10 (SVSG) Blower switch ON (Vol: 3) Below 100 ohms F22-9 (BLRH) - F22-10 (SVSG) Blower switch OFF 1.54 to 2.86 kohms F22-9 (BLRH) - F22-10 (SVSG) Blower switch ON (Vol: 3) Below 100 ohms TEXT IN ILLUSTRATION *1 Component without harness connected (Seat Heater Switch) NG --> See step 30 OK: Go to next step
19. CHECK HARNESS AND CONNECTOR (SEAT HEATER SWITCH - A/C AMPLIFIER) Disconnect the F48 connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F22-7 (BLLH) - F48-4 (SVDS) Always Below 1 ohms F22-8 (SVS5) - F48-8 (S5-2) Always Below 1 ohms F22-9 (BLRH) - F48-17 (SVPS) Always Below 1 ohms F22-10 (SVSG) - F48-7 (SG-6) Always Below 1 ohms F22-7 (BLLH) - Body ground Always 10 kohms or higher F22-8 (SVS5) - Body ground Always 10 kohms or higher F22-9 (BLRH) - Body ground Always 10 kohms or higher F22-10 (SVSG) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 31
20. REPLACE SEAT BACK CLIMATE CONTROL BLOWER LH. Refer to «DISASSEMBLY - Step 22»(ref-398249-S24762494412011051600000)
21. REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH. Refer to «DISASSEMBLY - Step 27»(ref-398249-S24762494412011051600000)
22. REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY LH. Refer to «DISASSEMBLY - Step 27»(ref-398249-S24762494412011051600000)
23. REPLACE SEAT HEATER SWITCH. Refer to «REMOVAL»(ref-398249-S34920053172011051600000)
24. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»(ref-398224-S23203152222011051600000)
25. REPLACE SEAT BACK CLIMATE CONTROL BLOWER RH. Refer to «DISASSEMBLY - Step 22»(ref-398249-S24762494412011051600000)
26. REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY RH. Refer to «DISASSEMBLY - Step 27»(ref-398249-S24762494412011051600000)
27. REPLACE SEAT CUSHION CLIMATE CONTROL BLOWER ASSEMBLY RH. Refer to «DISASSEMBLY - Step 27»(ref-398249-S24762494412011051600000)
28. REPLACE SEAT HEATER SWITCH. Refer to «REMOVAL»(ref-398249-S34920053172011051600000)
29. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»(ref-398224-S23203152222011051600000)
30. REPLACE SEAT HEATER SWITCH. Refer to «REMOVAL»(ref-398249-S34920053172011051600000)
31. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»(ref-398224-S23203152222011051600000)