Check Bus 3 Lines for Short Circuit [10/2019 - 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 IN CAN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR)
- Disconnect the cable from the negative (-) auxiliary battery terminal.
- Disconnect the No. 5 CAN junction connector.
- Measure the resistance according to the value(s) in the table below.
*a Front view of wire harness connector
(to No. 5 CAN Junction Connector)*b to Central Gateway ECU (Network Gateway ECU) Standard Resistance
Tester Connection Condition Specified Condition Connected to F91-1 (CANH) - F91-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU) F91-2 (CANH) - F91-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU) Result
Proceed to OK NG
Result:
NG
See step 4
Result:
OK
See step 2
- CHECK FOR SHORT IN CAN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR)
- Disconnect the No. 5 CAN junction connector.
- Measure the resistance according to the value(s) in the table below.
*a Front view of wire harness connector
(to No. 5 CAN Junction Connector)*b to Radio Receiver Assembly *c to DCM (Telematics Transceiver)
(for Lexus Enform)*d to Stereo Component Equalizer Assembly
(w/ ASC System)Standard Resistance
Tester Connection Condition Specified Condition Connected to F92-8 (CANH) - F92-19 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Radio receiver assembly F92-9 (CANH) - F92-20 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher DCM (telematics transceiver)*1 F92-10 (CANH) - F92-21 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Stereo component equalizer assembly*2 - *1: w/ Telematics Transceiver
- *2: w/ ASC System
Result
Proceed to OK NG
Result:
OK
REPLACE NO. 5 CAN JUNCTION CONNECTOR
Result:
NG
See step 3
- CHECK FOR SHORT IN CAN BUS LINES (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 short circuited branch line is connected.
Refer to TERMINALS OF ECU [10/2019 - 08/2021] , or refer to TERMINALS OF ECU [08/2021 - 07/2022]
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition F61-6 (CA3H) - F61-21 (CA3L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω *a Component with harness connected
(Central Gateway ECU (Network Gateway ECU))HINT:
- If the resistance becomes normal (between 54 and 69 Ω) 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 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
- CHECK FOR SHORT IN CAN BUS LINES (NO. 5 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.
*a Front view of wire harness connector
(to No. 5 CAN Junction Connector)*b to Central Gateway ECU (Network Gateway ECU) Standard Resistance
Tester Connection Condition Specified Condition F91-1 (CANH) - F91-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher F91-2 (CANH) - F91-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU). Refer to REMOVAL [10/2018 - 07/2022]
Result:
NG
REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 5 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))