DTC 4-2: Green LED Error: Procedure

1. Disconnect the M16 ECU connector.
   Fig 1: Identifying Roof Console Box & Mayday ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the O2 roof console box connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance

   Tester Connection	Specified Condition
   M16-11 (IND2) - O2-8 (IND2)	Below 1 Ω
   M16-11 (IND2) or O2-8 (IND2) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Temporarily replace the roof console box assembly. Refer to REMOVAL with a new or normally functioning one.
2. Check that the system operates normally.

   OK

   Green LED operates normally.

   NOTE:

   If replacement of the ECU is necessary, replace the mayday battery (backup battery) together with the ECU. After the replacement, register the ECU. Refer to REGISTRATION .

NG → See step   3 

OK → END