Inspection Procedure: Procedure

1. Check for DTCs.

   HINT: 

   If the CAN MS bus communication error DTC U1002 is output, troubleshoot for U1002 and check for malfunctions in the CAN MS main bus circuit. Refer to DTC U1002 (CAN MS BUS): Lost Communication with Gateway Module (Main body ECU) .

   Result

   Result	Proceed to
   U1002 is not output	A
   U1002 is output	B

B → See step   4 

A: Go to next step 

1. Turn the ignition switch off.
2. Disconnect the certification ECU connector from the certification ECU.
   Fig 1: Identifying E36 Certification 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	Switch Condition	Specified Condition
   E36-27 (CANH) - E36-28 (CANL)	Ignition switch off	54 to 69 Ω

NG → REPAIR OR REPLACE CAN MS BUS BRANCH WIRE OR CONNECTOR (CERTIFICATION ECU) 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 2: View Of Wire Harness Connector To Certification ECU

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E36-17 (E) - Body ground	Always	Below 1 Ω

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   E36-18 (IG) - Body ground	Ignition switch ON	10 to 14 V
   E36-1 (+B) - Body ground	Always	10 to 14 V
   E36-19 (ACC) - Body ground	Ignition switch ACC	10 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE CERTIFICATION ECU