Rear Sunshade System - Rear Sunshade Shift-Linked Function Does Not Operate When Shift Lever Is Moved To R Position
SYSTEM DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK OPERATION
CHECK REAR SUNSHADE RELAY
CHECK WIRE HARNESS (MAIN BODY ECU LH - BACK-UP LIGHT SWITCH OR PNP SWITCH)
CHECK WIRE HARNESS (REAR SUNSHADE RELAY - MAIN BODT ECU LH)
REAR SUNSHADE SYSTEM - Rear Sunshade Shift-linked Function does not Operate when Shift Lever is Moved to R Position
SYSTEM DESCRIPTION
When the engine switch is on (IG) and the rear sunshade is raised, moving the shift lever to R causes the Park/Neutral Position switch (A/T) or back-up light switch (M/T) to send a reverse-linked signal to the main body ECU LH. Then the main body ECU LH sends the signal through the multiplex communication line to the rear sunshade relay. The relay then lowers the rear sunshade.
WIRING DIAGRAM

INSPECTION PROCEDURE
Check that the back-up light comes on when the shift lever is moved to the R position.
- OK:
- Back-up light comes on when shift lever is moved to R position.
OK | |
| |
REPLACE REAR SUNSHADE RELAY |
|
3.CHECK WIRE HARNESS (MAIN BODY ECU LH - BACK-UP LIGHT SWITCH OR PNP SWITCH) |
Disconnect the Q2 cowl side junction block LH connector.
Measure the voltage of the wire harness side connectors.
- Standard voltage:
Tester connection | Condition | Specified condition |
BKUP (Q2-22) - Body ground | Engine switch on (IG), shift lever on except R | Below 1 V |
BKUP (Q2-22) - Body ground | Engine switch on (IG), shift lever on R | 10 to 14 V |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4.CHECK WIRE HARNESS (REAR SUNSHADE RELAY - MAIN BODT ECU LH) |
Disconnect the Q24 relay connector.
Disconnect the Q2 main body ECU LH connector.
Measure the resistance of the wire harness side connectors.
- Standard resistance:
Tester connection | Condition | Specified condition |
REV (Q24-2) - OP02 (Q2-20) | Always | Below 1 Ω |
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
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LEXUS IS250, IS220d / GSE20 ALE20