4WD Control ECU Communication Stop Mode [09/2022 - 11/2022]: Procedure
WARNING: This page is about a different car, the 2023 Toyota GR Corolla and 2023 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR OPEN IN CAN BUS LINES (4WD ECU ASSEMBLY BRANCH LINE)
- Disconnect the cable from the negative (-) battery terminal.
- Disconnect the O177 4WD ECU assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition O177-17 (CANH) - O177-26 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω *a Front view of wire harness connector
(to 4WD ECU Assembly)Result
Result OK NG
Result:
NG
REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (4WD ECU ASSEMBLY)
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
- Disconnect the O176 4WD ECU assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition O176-1 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω *a Front view of wire harness connector
(to 4WD ECU Assembly) - Reconnect the cable to the negative (-) battery terminal.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition O176-24 (IG1) - Body ground Ignition switch ON 11 to 14 V O176-2 (BSLC) - Body ground Always 11 to 14 V Result
Result OK NG
Result:
OK
REPLACE 4WD ECU ASSEMBLY
Refer to REMOVAL [09/2022 - 11/2022]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)