Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Back Door Courtesy Switch Circuit
DESCRIPTION
Each fold seat control ECU receives back door courtesy light switch input signal to determine the state of the back door and enable or disable the fold and return functions.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
-
When a fold seat control ECU (RH/LH seat) is replaced, it is necessary to perform initialization.
Click here
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PROCEDURE
| 1. | CHECK REAR POWER SEAT CONTROL SYSTEM (for Third Row) |
(a) Check that the rear power seat control system (for Third Row) function operates normally.
| Result | Proceed to |
|---|---|
| Fold/Return functions of both rear No. 2 power seats do not operate normally. | A |
| Fold/Return functions of rear No. 2 power seat RH do not operate normally. | B |
| Fold/Return functions of rear No. 2 power seat LH do not operate normally. | C |
| B | .gif) | GO TO STEP 4 |
| C | | GO TO STEP 6 |
|
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| 2. | CHECK POWER BACK DOOR SYSTEM (w/ Outside Door Control Switch) |
(a) Check if the power back door system (w/ outside door control switch) operates normally.
Click here
OK:
Power back door system (w/ outside door control switch) operates normally.
| NG | | GO TO LIGHTING SYSTEM (BACK DOOR COURTESY SWITCH CIRCUIT) |
|
| 3. | CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (RH/LH SEAT) - BACK DOOR LOCK ASSEMBLY) |
(a) Disconnect the x15 fold seat control ECU (RH seat) connector.
(b) Disconnect the y15 fold seat control ECU (LH seat) connector.
(c) Disconnect the Z7 back door lock assembly connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| x15-19 (BDCY) or y15-19 (BDCY) - Z7-8 (CTY) | Always | Below 1 Ω |
| x15-19 (BDCY), y15-19 (BDCY) or Z7-8 (CTY) - Body ground | Always | 10 kΩ or higher |
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 4. | CHECK FOLD SEAT CONTROL ECU (RH SEAT) |
(a) Disconnect the y15 fold seat control ECU (LH seat) connector.
(b) Disconnect the Z7 back door lock assembly connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| Z7-8 (CTY) - Body ground | Always | 11 to 14 V |
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
| 5. | CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (RH SEAT) - BACK DOOR LOCK ASSEMBLY) |
(a) Disconnect the x15 fold seat control ECU (RH seat) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| x15-19 (BDCY) - Z7-8 (CTY) | Always | Below 1 Ω |
| OK | | REPLACE FOLD SEAT CONTROL ECU (RH SEAT) |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 6. | CHECK FOLD SEAT CONTROL ECU (LH SEAT) |
(a) Disconnect the x15 fold seat control ECU (RH seat) connector.
(b) Disconnect the Z7 back door lock assembly connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| Z7-8 (CTY) - Body ground | Always | 11 to 14 V |
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
| 7. | CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU (LH SEAT) - BACK DOOR LOCK ASSEMBLY) |
(a) Disconnect the y15 fold seat control ECU (LH seat) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| y15-19 (BDCY) - Z7-8 (CTY) | Always | Below 1 Ω |
| OK | | REPLACE FOLD SEAT SWITCH ASSEMBLY (LH SEAT) |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Rear Light Assembly: Disassembly
DISASSEMBLY CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH side and LH side.
The following procedure is for the LH side.
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Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual
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Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual
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