Brake Booster (Skid Control ECU) Communication Stop Mode [09/2023 - ]: Procedure
WARNING: This page is about a different car, the 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR OPEN IN CAN BUS LINES (NO. 1 SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY) BRANCH LINE)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the B35 No. 1 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B35-36 (CA1H) - B35-37 (CA1L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (NO. 1 SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY))
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition B35-21 (GND2) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω - 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 Condition Specified Condition B35-1 (BM) - Body ground Ignition switch off 11 to 14 V B35-30 (IGR) - Body ground Ignition switch ON 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE NO. 1 SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY). Refer to REMOVAL [09/2023 - 12/2023] , or refer to REMOVAL [12/2023 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
- Measure the resistance according to the value(s) in the table below.