Lexus IS250 IS220d GSE20 ALE20 - DOOR LOCK
READ VALUE OF DATA LIST (DOOR UNLOCK DETECTION SWITCH)
INSPECT FRONT DOOR LOCK ASSEMBLY (DOOR UNLOCK DETECTION SWITCH)
CHECK WIRE HARNESS (FRONT DOOR LOCK ASSEMBLY - MULTIPLEX NETWORK MASTER SWITCH)
POWER DOOR LOCK CONTROL SYSTEM - Driver Side Door UNLOCK Detection Switch Circuit
DESCRIPTION
The driver's door unlock detection switch is built into the driver's door lock assembly. The switch turns on when the driver's door is locked and turns off when the door is unlocked.
The multiplex network master switch assembly is connected to the driver's door lock assembly via terminal LSW and driver's door lock/unlock state signals are input to the multiplex network master switch assembly.
The multiplex network master switch assembly applies voltage to the door unlock detection switch via terminal LSW. When the door unlock detection switch is on (there is continuity between the switch terminals), a lock state signal is input to the multiplex network master switch assembly. When the switch is off (there is no continuity between the switch terminals), an unlock state signal is input.
The multiplex network master switch assembly sends driver's door lock/unlock state information to the main body ECU RH using multiplex communication.
WIRING DIAGRAM
INSPECTION PROCEDURE
1.READ VALUE OF DATA LIST (DOOR UNLOCK DETECTION SWITCH) |
Check the DATA LIST to ensure proper function of the door unlock detection switch.
Item | Measurement Item / Display (Range) | Normal Condition | Diagnostic Note |
Door Unlock Detection SW | Driver side door unlock detection switch signal /ON or OFF | ON: Driver side door is unlocked OFF: Driver side door is locked | - |
- OK:
- The display is as specified in the normal condition column.
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OK | ||
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2.INSPECT FRONT DOOR LOCK ASSEMBLY (DOOR UNLOCK DETECTION SWITCH) |
LHD Models:

Remove the front door lock assembly LH.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Measurement Condition Door Lock Condition Specified Condition 7 - 8 Battery positive (+) → Terminal 4
Battery negative (-) → Terminal 3Lock 10 kΩ or higher 7 - 8 Battery positive (+) → Terminal 3
Battery negative (-) → Terminal 4Unlock Below 1 Ω
RHD Models:
Remove the front door lock assembly RH.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Measurement Condition Door Lock Condition Specified Condition 7 - 8 (*1) Battery positive (+) → Terminal 2
Battery negative (-) → Terminal 1Lock 10 kΩ or higher 7 - 8 (*1) Battery positive (+) → Terminal 1
Battery negative (-) → Terminal 2Unlock Below 1 Ω 7 - 8 (*2) Battery positive (+) → Terminal 4
Battery negative (-) → Terminal 1Lock 10 kΩ or higher 7 - 8 (*2) Battery positive (+) → Terminal 1
Battery negative (-) → Terminal 4Unlock Below 1 Ω
*1: w/ Double locking system
*2: w/o Double locking system
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OK | |
3.CHECK WIRE HARNESS (FRONT DOOR LOCK ASSEMBLY - MULTIPLEX NETWORK MASTER SWITCH) |

Disconnect the front door lock assembly connector.
Disconnect the multiplex network master switch assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection
(Symbols)Condition Specified Condition M2-8 (LSSR) - M7-16 (LSW) (*1) Always Below 1 Ω M2-7 (E) - Body ground (*1) Always Below 1 Ω L8-7 (LSSR) - L17-16 (LSW) (*2) Always Below 1 Ω L8-8 (E) - Body ground (*2) Always Below 1 Ω
*1: LHD Models
*2: RHD Models
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OK | ||
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