- Short to ground in CAN main bus line
- Short to ground in CAN branch line
- Central gateway ECU (network gateway ECU)
- Air conditioning amplifier assembly
- Certification ECU (smart key ECU assembly)
- Main body ECU (multiplex network body ECU)
- Combination meter assembly
-
Meter mirror sub-assembly
(w/ Headup Display System)
-
Headlight ECU sub-assembly RH
(w/ AFS)
-
Headlight ECU sub-assembly LH
(w/ AFS)
- No. 3 CAN junction connector
| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001CBPA |
| Model Year Start: 2019 | Model: GR Corolla | Prod Date Range: [06/2018 - 01/2019] |
| Title: NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): Check Bus 5 Line for Short to GND; 2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019] | ||
|
Check Bus 5 Line for Short to GND |
DESCRIPTION
There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 15 (CA5H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 16 (CA5L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3.
|
Symptom |
Trouble Area |
|---|---|
|
There is no resistance between terminal 15 (CA5H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 16 (CA5L) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3. |
|
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 1 minute 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 main body ECU (multiplex network body ECU) or certification ECU (smart key ECU assembly), 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 TO GND IN CAN BUS LINE (NO. 3 CAN JUNCTION CONNECTOR) |
(a) Disconnect the cable from the negative (-) battery terminal.
(b) Disconnect the I94 No. 3 CAN junction connector.
(c) Measure the resistance according to the value(s) in the table below.
|
*1 |
DLC3 |
- |
- |
|
*a |
Front view of wire harness connector (to No. 3 CAN Junction Connector) |
*b |
to Combination Meter Assembly |
|
*c |
to Main Body ECU (Multiplex Network Body ECU) |
*d |
to Meter Mirror Sub-assembly (w/ Headup Display System) |
|
*e |
to Air Conditioning Amplifier Assembly |
*f |
to Certification ECU (Smart Key ECU Assembly) |
|
*g |
to Central gateway ECU (Network Gateway ECU) |
*h |
to Headlight ECU Sub-assembly RH (w/ AFS) |
|
*i |
to Headlight ECU Sub-assembly LH (w/ AFS) |
- |
- |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
Connected to |
|---|---|---|---|
|
I94-1 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Combination meter assembly |
|
I94-11 (CANL) - I26-4 (CG) |
|||
|
I94-2 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Main body ECU (multiplex network body ECU) |
|
I94-12 (CANL) - I26-4 (CG) |
|||
|
I94-3 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Meter mirror sub-assembly*1 |
|
I94-13 (CANL) - I26-4 (CG) |
|||
|
I94-4 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Air conditioning amplifier assembly |
|
I94-14 (CANL) - I26-4 (CG) |
|||
|
I94-5 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Certification ECU (smart key ECU assembly) |
|
I94-15 (CANL) - I26-4 (CG) |
|||
|
I94-6 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Central gateway ECU (network gateway ECU) |
|
I94-16 (CANL) - I26-4 (CG) |
|||
|
I94-7 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Headlight ECU sub-assembly RH*2 |
|
I94-17 (CANL) - I26-4 (CG) |
|||
|
I94-8 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
Headlight ECU sub-assembly LH*2 |
|
I94-18 (CANL) - I26-4 (CG) |
- *1: w/ Headup Display System
- *2: w/ AFS
|
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. 3 CAN JUNCTION CONNECTOR |
| C |
|
|
|
2. |
CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 3 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.
|
*1 |
DLC3 |
- |
- |
|
*a |
Front view of wire harness connector (to No. 3 CAN Junction Connector) |
*b |
to Central Gateway ECU (Network Gateway ECU) |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I94-6 (CANH) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
|
I94-16 (CANL) - I26-4 (CG) |
| OK |
|
| NG |
|
REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 3 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) |
|
3. |
CHECK FOR SHORT TO GND IN CAN BUS LINE (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 bus line shorted to GND is connected.
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(c) 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 |
|---|---|---|
|
I53-15 (CA5H) - I26-4 (CG) |
Cable disconnected from negative (-) battery terminal |
200 Ω or higher |
|
I53-16 (CA5L) - I26-4 (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.
| OK |
|
REPLACE ECU OR SENSOR |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|