DTC B1206: P/W Master Switch Communication Stop: Procedure

1. Remove the MPX-B fuse from the No. 1 engine room relay block.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   MPX-B fuse	Always	Below 1 Ω

NG → REPLACE FUSE (MPX-B) 

OK: Go to next step 

1. Disconnect the M18 connector.
   Fig 1: M18 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the engine switch on (IG).
3. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   M18-15 (CPUB) - Body ground	Always	11 to 14 V

   Standard Resistance

   Tester Connection	Condition	Specified Connection
   M18-12 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MULTIPLEX NETWORK MASTER SWITCH - BATTERY AND BODY GROUND) 

OK: Go to next step 

1. Disconnect the M18, Q3 and P33 connectors.
   Fig 2: M18, Q3 And P33 Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M18-3 (MPX1) - Q3-15 (MPX1)	Always	Below 1 Ω
   M18-2 (MPX2) - P33-28 (MPX2)	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4