Main Body ECU Communication Stop Mode [11/2022 - ]: Procedure
WARNING: This page is about a different car, the 2025 Toyota Corolla Cross, 2024 Toyota Corolla Cross, and 2023 Toyota Corolla Cross. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR OPEN IN CAN BUS LINES (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) MAIN LINE)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the main body ECU (multiplex network body ECU) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition I85-2 (CANH) - I85-1 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω *a Front view of wire harness connector
(to Main Body ECU (Multiplex Network Body ECU))Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (BECU SIGNAL CIRCUIT)
- Remove the main body ECU (multiplex network body ECU).
Refer to REMOVAL [11/2022 - ]
- Reconnect the cable to the negative (-) auxiliary battery terminal.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition MB-26 (BECU) - Body ground Ignition switch off 11 to 14 V *1 Power Distribution Box Assembly NOTE:Perform this inspection with the wire harness connected to the power distribution box assembly.
Result
Proceed to OK NG
Result:
OK
CHECK ECU POWER SOURCE CIRCUIT
Refer to IG Signal Circuit [11/2022 - ]
Result:
NG
See step 3
- Remove the main body ECU (multiplex network body ECU).
- CHECK HARNESS AND CONNECTOR (BECU SIGNAL CIRCUIT)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the power distribution box assembly connector.
- Reconnect the cable to the negative (-) auxiliary battery terminal.
- Measure the voltage according to the value(s) in the table below.
*a Front view of wire harness connector
(to Power Distribution Box Assembly)Standard Voltage
Tester Connection Switch Condition Specified Condition 8E-23 - Body ground Ignition switch off 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE POWER DISTRIBUTION BOX ASSEMBLY
Refer to REMOVAL [11/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (BECU SIGNAL CIRCUIT)