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.

CHECK HARNESS AND CONNECTOR (MAYDAY ECU - MAP LIGHT (MAYDAY SWITCH))

Disconnect the R23 ECU connector
Disconnect the X6 map light connector
Measure the resistance according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
R23-4 (IND1) - X6-4 (IND1)	Always	Below 1 Ω
R23-4 (IND1) or X6-4 (IND1) - Body ground	Always	10 kΩ or higher

Fig 1: Checking Harness And Connector (Mayday ECU - MAP Light (Mayday Switch))

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR THEN CLEAR HISTORIC DTC

OK: Go to next step

CHECK MAP LIGHT ASSEMBLY (RED LED OPERATION)
1. Temporarily replace the map light with a new or normally functioning one (see REMOVAL ).
2. Check that the system operates normally.
  OK: Red LED operates normally.
  
  NG: REPLACE MAYDAY ECU TOGETHER WITH MAYDAY BATTERY AND THEN PERFORM REGISTRATION
  
  OK: END (MAP LIGHT (RED LED) IS FAULTY; CLEAR HISTORIC DTC)