DTC U1002: Lost Communication with Gateway Module (MS Bus); DTC U1114: Lost Communication with Main Switch Module [08/2014 - ]: Procedure

1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and branch wire.
   WARNING:

   Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected. Refer to INITIALIZATION [08/2014 - ] .

NEXT: Go to next step 

1. Disconnect the F10 main body ECU (multiplex network body ECU) connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   F10-9 (CANP) - F10-10 (CANN)	Ignition switch off	108 to 132 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

NG → See step   4 

OK: Go to next step 

1. Connect the cable to the negative (-) battery terminal.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

   *a

   Rear view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

   *b

   Front view of wire harness connector (to Main Body ECU [Multiplex Network Body ECU])

   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected. Refer to INITIALIZATION [08/2014 - ] .

2. Remove the main body ECU (multiplex network body ECU). Refer to REMOVAL [08/2014 - ] .
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F10-3 (GND2) - Body ground	Always	Below 1 Ω
   A-11 (GND1) - Body ground	Always	Below 1 Ω

4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A-31 (ALTB) - Body ground	Always	11 to 14 V
   A-30 (BECU) - Body ground	Always	11 to 14 V
   A-29 (ACC) - Body ground	Ignition switch ACC	11 to 14 V
   A-32 (IG) - Body ground	Ignition switch ON	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   7 

1. Reconnect the F10 main body ECU (multiplex network body ECU) connector.

NEXT: Go to next step 

1. Disconnect the U1 drive monitor switch connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   U1-1 (CANP) - U1-2 (CANN)	Ignition switch off	108 to 132 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Drive Monitor Switch)

NG → REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (MAIN BODY ECU - DRIVE MONITOR SWITCH) 

OK: Go to next step 

1. Connect the cable to the negative (-) battery terminal.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected. Refer to INITIALIZATION [08/2014 - ] .

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   U1-7 (GND) - Body ground	Always	Below 1 Ω

3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   U1-6 (+B) - Body ground	Always	11 to 14 V
   U1-12 (IG) - Body ground	Ignition switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Drive Monitor Switch)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   8