DTC B1271: Combination Meter ECU Communication Stop: Procedure

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

   Standard Resistance

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

NG → REPLACE FUSE (DOME, MPX-B) 

OK: Go to next step 

1. Disconnect the J34 connector.
   Fig 1: Identifying J34 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage and resistance of the wire harness side connector.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   J34-23 (B) - Body ground	Always	11 to 14 V
   J34-24 (B) - Body ground	Always	11 to 14 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   J34-1 (E2) - Body ground	Always	Below 1 Ω
   J34-13 (ES) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Combination Meter Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - BATTERY AND BODY GROUND) 

OK: Go to next step 

1. Disconnect the J34, J49 and J58 connectors.*1
   Fig 2: J34, J49 And J58 Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the J34, J76 and J58 connectors.*2
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   J34-18 (MPX-) - J49-3 (MPX1)*1	Always	Below 1 Ω
   J34-18 (MPX-) - J76-4 (MPI1)*2	Always	Below 1 Ω
   J34-6 (MPX+) - J58-31 (MPX-)	Always	Below 1 Ω

   • *1: w/ Occupant Classification System
   • *2: w/o Occupant Classification System
   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Combination Meter)
   *2	Front view of wire harness connector (to Tire Pressure Warning ECU and Receiver)
   *3	Front view of wire harness connector (to A/C Amplifier)
   *4	Front view of wire harness connector (to Gateway ECU)
   *5	w/ Occupant Classification System
   *6	w/o Occupant Classification System

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4