Check Bus 1 Line for Short to GND [07/2022 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 2 CAN JUNCTION CONNECTOR)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the No. 2 CAN junction connector.
- Measure the resistance according to the value(s) in the table below.
*1 DLC3 - - *a Front view of wire harness connector
(to No. 2 CAN Junction Connector)*b to No. 8 CAN Junction Connector *c to Central Gateway ECU (Network Gateway ECU) *d to Clearance Warning ECU Assembly
(w/ Parking Support Alert System)*e to Forward Recognition Camera *f to Millimeter Wave Radar Sensor Assembly Standard Resistance
Tester Connection Condition Specified Condition Connected to F86-1 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 8 CAN Junction Connector F86-7 (CANL) - F58-4 (CG) F86-2 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central Gateway ECU (Network Gateway ECU) F86-8 (CANL) - F58-4 (CG) F86-3 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Clearance Warning ECU Assembly*1 F86-9 (CANL) - F58-4 (CG) F86-5 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Forward Recognition Camera F86-11 (CANL) - F58-4 (CG) F86-6 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Millimeter Wave Radar Sensor Assembly F86-12 (CANL) - F58-4 (CG) - *1: w/ Parking Support Alert System
Result
Result Proceed to OK A NG (Line to central gateway ECU (network gateway ECU)) B NG (Line to No. 8 CAN junction connector) C NG (Line to ECU or sensor) D
Result:
A
REPLACE NO. 2 CAN JUNCTION CONNECTOR
Result:
C
See step 3
Result:
D
See step 4
Result:
B
See step 2
- CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 2 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))
- Disconnect the F61 central gateway ECU (network gateway ECU) connector.
- Measure the resistance according to the value(s) in the table below.
*1 DLC3 - - *a Front view of wire harness connector
(to No. 2 CAN Junction Connector)*b to Central Gateway ECU (Network Gateway ECU) Standard Resistance
Tester Connection Condition Specified Condition F86-2 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher F86-8 (CANL) - F58-4 (CG) Result
Proceed to OK NG
Result:
OK
REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU). Refer to REMOVAL [07/2022 - ]
Result:
NG
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))
- CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 8 CAN JUNCTION CONNECTOR)
- Disconnect the No. 8 CAN junction connector.
- Measure the resistance according to the value(s) in the table below.
*1 DLC3 - - *a Front view of wire harness connector
(to No. 8 CAN Junction Connector)*b to Rear Television Camera Assembly *c to Blind Spot Monitor Sensor LH
(w/ Blind Spot Monitor System)*d to No. 2 CAN Junction Connector *e to No. 2 CAN Junction Terminal - - Standard Resistance
Tester Connection Condition Specified Condition Connected to N117-4 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear Television Camera Assembly N117-15 (CANL) - F58-4 (CG) N117-5 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Blind Spot Monitor Sensor LH*1 N117-16 (CANL) - F58-4 (CG) N117-7 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN Junction Connector N117-18 (CANL) - F58-4 (CG) N117-8 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher No. 2 CAN Junction Terminal N117-19 (CANL) - F58-4 (CG) - *1: w/ Blind Spot Monitor System
Result
Result Proceed to OK A NG (Line to No. 2 CAN junction connector) B NG (Line to ECU or sensor) C
Result:
A
REPLACE NO. 8 CAN JUNCTION CONNECTOR
Result:
B
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 8 CAN JUNCTION CONNECTOR)
Result:
C
See step 4
- CHECK FOR SHORT TO GND IN CAN BUS LINE (ECU OR SENSOR)
- Reconnect all wire harness connectors.
- Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the bus line shorted to GND is connected.
Refer to TERMINALS OF ECU [07/2022 - ]
- Measure the resistance according to the value(s) in the table below.
*1 DLC3 - - *a Component with harness connected
(Central Gateway ECU (Network Gateway ECU))- - Standard Resistance
Tester Connection Condition Specified Condition F61-23 (CA1H) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher F61-8 (CA1L) - F58-4 (CG) HINT:
- If the resistance changes to 200 Ω or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.
- If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short to ground in the wire harness and repair or replace the wire harness or connector if necessary.
Result
Proceed to OK NG
Result:
OK
REPLACE ECU OR SENSOR
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR