NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): U115C87; Lost Communication with ECM/PCM "A" (ch5) Missing Message; 2023 MY Corolla Corolla Hatchback GR Corolla [11/2022 - 03/2023]

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM1000000028ABE
Model Year Start: 2023	Model: GR Corolla	Prod Date Range: [11/2022 - 03/2023]
Title: NETWORKING: CAN COMMUNICATION SYSTEM (for Gasoline Model): U115C87; Lost Communication with ECM/PCM "A" (ch5) Missing Message; 2023 MY Corolla Corolla Hatchback GR Corolla [11/2022 - 03/2023]

DTC

U115C87

Lost Communication with ECM/PCM "A" (ch5) Missing Message

DESCRIPTION

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
U115C87	Lost Communication with ECM/PCM "A" (ch5) Missing Message	Communication stops between the brake actuator assembly and the ECM.	CAN main bus lines or connector ECM Brake actuator assembly No. 11 can junction connector	DTC Output from ECM Brake actuator assembly

WIRING DIAGRAM

except G16E-GTS

for G16E-GTS

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.
Click here
Before measuring the resistance of the CAN bus, turn the ignition 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 the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) battery terminal.
Click here
When disconnecting and reconnecting the battery.
HINT:

When disconnecting and reconnecting the battery, there is an automatic learning function that completes learning when the respective system is used.

Click here
Some parts must be initialized and set when replacing or removing and installing parts.
Click here
After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the ignition switch to ON 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.
Click here

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 VEHICLE TYPE

(a) Check vehicle type.

Result	Proceed to
except G16E-GTS	A
for G16E-GTS	B

B

A

2.	CHECK FOR OPEN IN CAN MAIN BUS LINES

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Measure the resistance according to the value(s) in the table below.

*a

Component with harness connected

(No. 11 CAN Junction Connector)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - A147-13 (CANL)	Cable disconnected from negative (-) battery terminal	Below 70 Ω

NG

OK

3.	CHECK FOR SHORT IN CAN BUS LINES

(a) Measure the resistance according to the value(s) in the table below.

*a

Component with harness connected

(No. 11 CAN Junction Connector)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - A147-13 (CANL)	Cable disconnected from negative (-) battery terminal	54 Ω or higher

NG

OK

4.	CHECK FOR SHORT TO +B IN CAN BUS LINE

(a) Measure the resistance according to the value(s) in the table below.

*1

DLC3

-

-

*a

Component with harness connected

(No. 11 CAN Junction Connector)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A147-13 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

NG

OK

5.	CHECK FOR SHORT TO GND IN CAN BUS LINE

(a) Measure the resistance according to the value(s) in the table below.

*1

DLC3

-

-

*a

Component with harness connected

(No. 11 CAN Junction Connector)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - I26-4 (CG)	Cable disconnected from negative (-)battery terminal	200 Ω or higher
A147-13 (CANL) - I26-4 (CG)	Cable disconnected from negative (-)battery terminal	200 Ω or higher

OK

INSPECT FOR INTERMITTENT PROBLEMS

NG

6.	CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A147 No. 11 CAN junction 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. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
A147-13 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

NG

OK

7.	CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Measure the resistance according to the value(s) in the table below.

*1

DLC3

-

-

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
A147-12 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

OK

REPLACE NO. 11 CAN JUNCTION CONNECTOR

NG

8.	CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A51 brake actuator assembly 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. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
A147-13 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

9.	CHECK FOR SHORT TO GND IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Disconnect the A47 ECM 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. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
A147-12 (CANL) - I26-4 (CG)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - ECM)

10.	CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A147 No. 11 CAN junction 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. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A147-13 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

NG

OK

11.	CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Measure the resistance according to the value(s) in the table below.

*1

DLC3

-

-

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A147-12 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

OK

REPLACE NO. 11 CAN JUNCTION CONNECTOR

NG

12.	CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A51 brake actuator assembly 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. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A147-13 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

13.	CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Disconnect the A47 ECM 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. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A147-12 (CANL) - I26-16 (BAT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - ECM)

14.	CHECK FOR SHORT IN CAN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A147 No. 11 CAN junction connector.

(b) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - A147-13 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

NG

OK

15.	CHECK FOR SHORT IN CAN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - A147-12 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

OK

REPLACE NO. 11 CAN JUNCTION CONNECTOR

NG

16.	CHECK FOR SHORT IN CAN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A51 brake actuator assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - A147-13 (CANL)	Cable disconnected from negative (-) battery terminal	1 MΩ or higher

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

17.	CHECK FOR SHORT IN CAN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Disconnect the A47 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - A147-12 (CANL)	Cable disconnected from negative (-) battery terminal	1 MΩ or higher

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - ECM)

18.	CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR)

(a) Disconnect the A147 No. 11 CAN junction connector.

(b) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to Brake Actuator Assembly

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-2 (CANH) - A147-13 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

NG

OK

19.	CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to No. 11 CAN Junction Connector)

*b

to ECM

Standard Resistance:

Tester Connection	Condition	Specified Condition
A147-1 (CANH) - A147-12 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

OK

REPLACE NO. 11 CAN JUNCTION CONNECTOR

NG

20.	CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

(a) Reconnect the A147 No. 11 CAN junction connector.

(b) Disconnect the A51 brake actuator assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A51-11 (CA2H) - A51-25 (CA2L)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

*a	Front view of wire harness connector (to Brake Actuator Assembly)

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - BRAKE ACTUATOR ASSEMBLY)

21.	CHECK FOR OPEN IN CAN MAIN BUS LINES (NO. 11 CAN JUNCTION CONNECTOR - ECM)

(a) Reconnect the A147 No. 11 CAN junction connector.

(b) Disconnect the A47 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A47-7 (CAN+) - A47-17 (CAN-)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

*a	Front view of wire harness connector (to ECM)

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 11 CAN JUNCTION CONNECTOR - ECM)

22.	CHECK FOR OPEN IN CAN MAIN BUS LINES

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the A140 brake actuator assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-17 (CA2L)	Cable disconnected from negative (-) battery terminal	Below 133 Ω

*a	Front view of wire harness connector (to Brake Actuator Assembly)

NG

OK

23.	CHECK FOR SHORT IN CAN BUS LINES

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-17 (CA2L)	Cable disconnected from negative (-) battery terminal	108 Ω or higher

*a	Front view of wire harness connector (to Brake Actuator Assembly)

NG

OK

24.	CHECK FOR SHORT TO +B IN CAN BUS LINE

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-14 (+BS)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A140-17 (CA2L) - A140-14 (+BS)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

*a	Front view of wire harness connector (to Brake Actuator Assembly)

NG

OK

25.	CHECK FOR SHORT TO GND IN CAN BUS LINE

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-1 (GND1)	Cable disconnected from negative (-)battery terminal	200 Ω or higher
A140-17 (CA2L) - A140-1 (GND1)	Cable disconnected from negative (-)battery terminal	200 Ω or higher

*a	Front view of wire harness connector (to Brake Actuator Assembly)

NG

OK

26.	CHECK FOR OPEN IN CAN MAIN BUS LINES (ECM)

(a) Reconnect the A140 brake actuator assembly connector.

(b) Disconnect the A139 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to ECM)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A139-25 (CANU) - A139-26 (CAND)	Cable disconnected from negative (-) battery terminal	Below 133 Ω

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

OK

27.	CHECK FOR SHORT IN CAN BUS LINES (ECM - BRAKE ACTUATOR ASSEMBLY)

(a) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to ECM)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A139-25 (CANU) - A139-26 (CAND)	Cable disconnected from negative (-) battery terminal	108 Ω or higher

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

OK

28.	CHECK FOR SHORT TO +B IN CAN BUS LINE (ECM - BRAKE ACTUATOR ASSEMBLY)

(a) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to ECM)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A139-25 (CANU) - A139-1 (BATT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A139-26 (CAND) - A139-1 (BATT)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

OK

29.	CHECK FOR SHORT TO GND IN CAN BUS LINE (BRAKE ACTUATOR ASSEMBLY - ECM)

(a) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to ECM)

-

-

Standard Resistance:

Tester Connection	Condition	Specified Condition
A139-25 (CANU) - A139-10 (E1)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
A139-26 (CAND) - A139-10 (E1)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

OK

INSPECT FOR INTERMITTENT PROBLEMS

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

30.	CHECK FOR SHORT TO GND IN CAN BUS LINE (BRAKE ACTUATOR ASSEMBLY - ECM)

(a) Disconnect the A139 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-1 (GND1)	Cable disconnected from negative (-) battery terminal	200 Ω or higher
A140-17 (CA2L) - A140-1 (GND1)	Cable disconnected from negative (-) battery terminal	200 Ω or higher

*a	Front view of wire harness connector (to Brake Actuator Assembly)

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - ECM)

31.	CHECK FOR SHORT TO +B IN CAN BUS LINE (BRAKE ACTUATOR ASSEMBLY - ECM)

(a) Disconnect the A139 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-14 (+BS)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher
A140-17 (CA2L) - A140-14 (+BS)	Cable disconnected from negative (-) battery terminal	6 kΩ or higher

*a	Front view of wire harness connector (to Brake Actuator Assembly)

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - ECM)

32.	CHECK FOR SHORT IN CAN BUS LINES (BRAKE ACTUATOR ASSEMBLY - ECM)

(a) Disconnect the A139 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A140-17 (CA2L)	Cable disconnected from negative (-) battery terminal	1 MΩ or higher

*a	Front view of wire harness connector (to Brake Actuator Assembly)

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - ECM)

33.	CHECK FOR OPEN IN CAN MAIN BUS LINES (BRAKE ACTUATOR ASSEMBLY)

(a) Disconnect the A139 ECM connector.

(b) Measure the resistance according to the value(s) in the table below.

*a

Front view of wire harness connector

(to Brake Actuator Assembly)

*b

Front view of wire harness connector

(to ECM)

Standard Resistance:

Tester Connection	Condition	Specified Condition
A140-16 (CA2H) - A139-25 (CANU)	Cable disconnected from negative (-) battery terminal	Below 1 Ω
A140-17 (CA2L) - A139-26 (CAND)	Cable disconnected from negative (-) battery terminal	Below 1 Ω

OK

NG

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (ECM - BRAKE ACTUATOR ASSEMBLY)