DTC U1100: Lost Communication with Seat Belt Control ECU [10/2014 - 10/2015]: Procedure

1. Reconfirm DTCs.

   HINT: 

   If DTC U1002 is output from PM1 Gateway of the power management control ECU, this indicates a sub bus 11 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 11.

   Result

   Result	Proceed to
   U1002 is not output from power management control ECU (Techstream display: PM1 Gateway)	A
   U1002 is output from power management control ECU (Techstream display: PM1 Gateway)	B

Result: 

B 

GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC 

(Refer to DTC U1002: Lost Communication with Gateway Module [10/2014 - 10/2015] )

Result: 

A 

See step  2

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the D27 seat belt control ECU connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D27-1 (CANH) - D27-2 (CANL)	Cable disconnected from negative (-) auxiliary battery terminal	54 to 69 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Seat Belt Control ECU)

Result: 

NG 

REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (SEAT BELT CONTROL ECU) 

Result: 

OK 

See step  3

1. Disconnect the D26 seat belt control ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D26-8 (PGND) - Body ground	Cable disconnected from negative (-) auxiliary battery terminal	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Seat Belt Control ECU)

3. Connect the cable to the negative (-) auxiliary battery terminal.
4. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   D26-7 (+B) - Body ground	Power switch off	11 to 14 V
   D27-8 (IG1) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Seat Belt Control ECU)

Result: 

OK 

REPLACE SEAT BELT CONTROL ECU 

(Refer to REMOVAL [10/2014 - 10/2015] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)