Inspection Procedure
WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
- Turn the ignition switch OFF before measuring the resistances of the CAN main wire and the CAN branch wire.
- After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
- Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If doors need to be opened in order to check connectors, open the doors and leave them open.
HINT:
Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
- CHECK CAN BUS LINE FOR DISCONNECTION (MAIN BODY ECU BRANCH WIRE)
- Turn the ignition switch OFF.
- Disconnect the D33 main body ECU connector.
- Measure the resistance.
Standard resistance
RESISTANCE SPECIFICATION CONDITION CHARTTester Connection Condition Specified Condition D33-23 (CANH) - D33-22 (CANL) Ignition switch OFF 54 to 69 Ω
NG: REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (CAN-H, CAN-L)
OK: GO TO NEXT STEP
- CHECK HARNESS AND CONNECTOR (BECU, IG, GND1)
- Disconnect the 4B and 4E main body ECU connectors.
- Measure the resistance.
Standard resistance
RESISTANCE SPECIFICATION CONDITION CHARTTester Connection Condition Specified Condition 4E-17(GND1)-Body ground Always Below 1 Ω - Measure the voltage.
Standard voltage
TESTER CONNECTION SPECIFIED CONDITIONTester Connection Condition Specified Condition 4B-30 (BECU) - Body ground Always 11 to 14 V - Reconnect the main body ECU connectors.
- Measure the voltage.
Standard voltage
TESTER CONNECTION SPECIFIED CONDITIONTester Connection Condition Specified Condition 4B-24 (IG) - Body ground Ignition switch ON 11 to 14 V
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: REPLACE MAIN BODY ECU