Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: When using the Intelligent tester or Techstream with the power switch OFF to troubleshoot: Connect the Intelligent tester or Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the tester and vehicle begins.

CHECK HARNESS AND CONNECTOR (REAR JUNCTION BLOCK ECU - MAP LIGHT)

Fig 1: Identifying Rear Junction Block ECU Connector S62 & Map Light Connector X6

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the S62 ECU connector
Disconnect the X6 Map light connector
Measure the resistance and voltage according to the value(s) in the table below

Standard resistance

RESISTANCE REFERENCE

Tester Connection	Condition	Specified Condition
S62-9 (LIN) - X6-2 (LIN)	Always	Below 1 Ω
S62-9 (LIN) or X6-2 (LIN) - Body ground	Always	10 kΩ or higher

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Condition
S62-9 (LIN) or X6-2 (LIN) - Body ground	Always	Below 1 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK HARNESS AND CONNECTOR (MAP LIGHT - BATTERY AND BODY GROUND)

Disconnect the X4 Map light connector.
Measure the resistance and voltage according to the value(s) in the table below.

Standard resistance

RESISTANCE REFERENCE

Tester Connection	Condition	Specified Condition
X4-16 (GND9) - Body ground	Always	Below 1 Ω

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Condition
X4-6 (+B) - Body ground	Always	11 to 14 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 2: Identifying Map Light X4 Connector Terminals

OK: Go to next step

CHECK MAP LIGHT ASSEMBLY (OPERATION)
1. Temporarily replace the map light assembly with a new or normally functioning one (see REMOVAL )
2. Clear the DTC (see DTC CHECK / CLEAR )

CHECK FOR DTC

Recheck for DTC (see DTC CHECK / CLEAR )

Result:

RESULT REFERENCE

Result	Proceed to
DTC B2405 output does not reoccur	A
DTC B2405 output reoccurs	B

B: REPLACE LUGGAGE ROOM JUNCTION BLOCK (REAR JUNCTION BLOCK ECU)

A: END (MAP LIGHT ASSEMBLY IS DEFECTIVE)