- Short in CAN main bus lines
- Short in CAN branch lines
- Central gateway ECU (network gateway ECU)
-
DCM (telematics transceiver)
(w/ Telematics Transceiver)
- Radio and display receiver assembly
- No. 4 CAN junction connector
| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM100000001CBOY |
| Model Year Start: 2019 | Model: GR Corolla | Prod Date Range: [06/2018 - 01/2019] |
| Title: NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): Check Bus 3 Lines for Short Circuit; 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019] | ||
|
Check Bus 3 Lines for Short Circuit |
DESCRIPTION
There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway ECU) is below 54 Ω.
|
Symptom |
Trouble Area |
|---|---|
|
Resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU (network gateway ECU) is below 54 Ω. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
NOTICE:
-
Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.
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![2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]; NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): HOW TO PROCEED WITH TROUBLESHOOTING](/t3Portal/stylegraphics/info.gif)
- Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 10 minutes or more before measuring the resistance.
-
After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
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-
After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the engine switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.
-
After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.
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-
Before replacing the DCM (telematics transceiver), refer to Registration.
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HINT:
- Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
- When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.
PROCEDURE
|
1. |
CHECK FOR SHORT IN CAN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR) |
(a) Disconnect the cable from the negative (-) battery terminal.
(b) Disconnect the I95 No. 4 CAN junction connector.
(c) Measure the resistance according to the value(s) in the table below.
|
*a |
Front view of wire harness connector (to No. 4 CAN Junction Connector) |
*b |
to Central Gateway ECU (Network Gateway ECU) |
|
*c |
to DCM (Telematics Transceiver) (w/ Telematics Transceiver) |
*d |
to Radio and Display Receiver Assembly |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
Connected to |
|---|---|---|---|
|
I95-1 (CANH) - I95-12 (CANL) |
Cable disconnected from negative (-) battery terminal |
108 to 132 Ω |
Central gateway ECU (network gateway ECU) |
|
I95-2 (CANH) - I95-13 (CANL) |
Cable disconnected from negative (-) battery terminal |
108 to 132 Ω |
Central gateway ECU (network gateway ECU) |
|
I95-3 (CANH) - I95-14 (CANL) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
DCM (telematics transceiver)* |
|
I95-4 (CANH) - I95-15 (CANL) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Radio and display receiver assembly |
- *: w/ Telematics Transceiver
|
Result |
Proceed to |
|---|---|
|
OK |
A |
|
NG (Line to central gateway ECU (network gateway ECU)) |
B |
|
NG (Line to ECU or sensor) |
C |
| A |
|
REPLACE NO. 4 CAN JUNCTION CONNECTOR |
| C |
|
|
|
2. |
CHECK FOR SHORT IN CAN BUS LINES (NO. 4 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
(a) Disconnect the I53 central gateway ECU (network gateway ECU) connector.
(b) Measure the resistance according to the value(s) in the table below.
|
*a |
Front view of wire harness connector (to No. 4 CAN Junction Connector) |
*b |
to Central Gateway ECU (Network Gateway ECU) |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I95-1 (CANH) - I95-12 (CANL) |
Cable disconnected from negative (-) battery terminal |
1 MΩ or higher |
|
I95-2 (CANH) - I95-13 (CANL) |
Cable disconnected from negative (-) battery terminal |
1 MΩ or higher |
| OK |
|
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 4 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
|
3. |
CHECK FOR SHORT IN CAN BUS LINES (ECU OR SENSOR) |
(a) Reconnect all wire harness connectors.
(b) Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited branch line is connected.
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|
(c) Measure the resistance according to the value(s) in the table below. Standard Resistance:
HINT:
|
|
| OK |
|
REPLACE ECU OR SENSOR |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|