BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1203; ECM Communication Circuit; 2019 - 2024 MY Camry HV [09/2018

Last Modified: 11-20-2023	6.11:8.1.0	Doc ID: RM100000001E82H
Model Year Start: 2019	Model: Camry HV	Prod Date Range: [09/2018 - ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1203; ECM Communication Circuit; 2019 - 2024 MY Camry HV [09/2018 - ]

DTC

C1203

ECM Communication Circuit

DESCRIPTION

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	MIL	Note
C1203	ECM Communication Circuit	1161	Either of the following is detected: Identification information sent from other ECUs does not match with the value stored when shipped from the factory. Identification information sent from other ECUs is not stored when shipped from the factory.	Other ECUs are not installed correctly Skid control ECU (brake booster with master cylinder assembly)	Comes on	INF Code 1161: SAE Code C124A Electronically controlled brake system DTC HINT: DTC C1203 (INF code 1161) is cleared when the conditions return to normal. This DTC is stored when incorrect identification information is detected and is not due to an ECM communication error.

NOTICE:

DTC C1203 is output when an incorrect ECU is installed. If initialization is performed and learning occurs with an incorrect ECU installed, operations and functions will differ from those stored when the vehicle was shipped from the factory. Therefore, make sure that learning occurs properly.

MONITOR DESCRIPTION

When the vehicle is being driven, if the vehicle information, drive type or steering wheel position cannot be confirmed, the memorized data does not match or other related information cannot be stored such as when the ECU that was installed when the vehicle left the factory is changed or the EEPROM is malfunctioning, the skid control ECU (brake booster with master cylinder assembly) illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs	C124A: CAN communication identification signal
Required Sensors/Components(Main)	Skid control ECU (brake booster with master cylinder assembly)
Required Sensors/Components(Related)	Skid control ECU (brake booster with master cylinder assembly) Speed sensor
Frequency of Operation	Continuous
Duration	-
MIL Operation	Immediately
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored	None
All of the following conditions are met	-
EEPROM read-in	Complete
IG1	On
Vehicle speed	40 km/h (25 mph) or more

TYPICAL MALFUNCTION THRESHOLDS

Both of the following conditions are met	A and B
A. Test Mode	Off
B. One of the following conditions is met	-
Grade info	Undetermined or different from a storage memory
Drive train info	Undetermined or different from a storage memory
Steering info	Undetermined or different from a storage memory
Car spec info	There is no write-in

COMPONENT OPERATING RANGE

All of the following conditions are met	-
EEPROM read-in	Complete
IG1	On
Test Mode	Off
Grade info	Decision and concordance from a storage memory
Drive train info	Decision and concordance from a storage memory
Steering info	Decision and concordance from a storage memory
Car spec info	There is write-in

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off.
Turn the power switch on (READY).
Turn the Techstream on.
Confirm that the vehicle is not in Test Mode and drive the vehicle at a speed of 40 km/h (25 mph) or more for 1 minute.
Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.
Read the DTCs.
HINT:
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
If the DTCs are not output, perform a universal trip and check for permanent DTCs.
Click here
HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTCs are output, the system is normal.

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

Click here

PROCEDURE

1.	CHECK PART NUMBER

(a) Check that the proper hybrid vehicle control ECU assembly and main body ECU (multiplex network body ECU) are installed.

OK:

Proper ECUs are installed.

(b) Check if the hybrid vehicle control ECU assembly and main body ECU (multiplex network body ECU) were replaced before the DTC was recorded.

OK:

ECUs were not replaced.

Result	Proceed to
OK	A
NG (A proper hybrid vehicle control ECU assembly is not installed and/or the hybrid vehicle control ECU assembly was replaced.)	B
NG (A proper main body ECU (multiplex network body ECU) is not installed and/or the main body ECU (multiplex network body ECU) was replaced.)	C

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

2.	PERFORM INITIALIZATION

(a) Perform linear solenoid valve offset learning, ABS holding solenoid valve learning and system information memorization.

Click here

Chassis > ABS/VSC/TRAC > Utility

Tester Display
ECB Utility

(b) Perform yaw rate and acceleration sensor zero point calibration.

Click here

Chassis > ABS/VSC/TRAC > Utility

Tester Display
Test Mode

HINT:

After installing a new skid control ECU (brake booster with master cylinder assembly), before performing linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization, DTC C1203 will be output.
If linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization are not performed, DTC C1203 will be output after the data stored in the skid control ECU (brake booster with master cylinder assembly) is cleared by performing "Reset Memory" using Techstream.

3.	RECONFIRM DTC

(a) Clear the DTCs.

Chassis > ABS/VSC/TRAC > Clear DTCs

(b) Turn the power switch off.

(d) Check if the same DTC is output.

Chassis > ABS/VSC/TRAC > Trouble Codes

Result	Proceed to
DTC C1203 is output.	A
DTC C1203 is not output.	B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

END