Toyota CH-R Service Manual: Lost Communication with Gateway Module (U1002)

Toyota CH-R Service Manual / Pre-collision / Pre-collision System / Lost Communication with Gateway Module (U1002)

DESCRIPTION

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U1002	Lost Communication with Gateway Module	When the ignition switch is ON, a communication error between the forward recognition camera and millimeter wave radar sensor assembly is detected for approximately 0.3 seconds.	CAN bus sub line or connector Forward recognition camera system Forward recognition camera Millimeter wave radar sensor assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.
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 turning the ignition 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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If the forward recognition camera has been replaced with a new one, be sure to perform forward recognition axis adjustment.
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When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed.

HINT:

Operating the ignition switch, any other switches or a door triggers related ECUs and sensors to communicate using the CAN communication system. This communication will cause the resistance value to change.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the connectors of ECUs or wire harnesses while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

1.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Check for DTCs.

Click here

Body Electrical > Pre-Collision 2 > Trouble Codes

Result	Proceed to
DTC U023A and/or U1002 and other DTCs are output	A
Only DTC U023A and/or U1002 is output	B

GO TO DIAGNOSTIC TROUBLE CODE CHART

2.	CHECK FOR OPEN IN CAN BUS SUB LINES (FORWARD RECOGNITION CAMERA)

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

(b) Disconnect the forward recognition camera connector.

*a	Front view of wire harness connector (to Forward Recognition Camera)

Standard Resistance:

Tester Connection	Condition	Specified Condition
R5-6 (CANH) - R5-12 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

(d) Connect the forward recognition camera connector.

REPAIR OR REPLACE CAN BUS SUB LINE OR CONNECTOR (FORWARD RECOGNITION CAMERA - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

3.	CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE (FORWARD RECOGNITION CAMERA))

(a) Disconnect the forward recognition camera connector.

*a	Front view of wire harness connector (to Forward Recognition Camera)

(b) Connect the cable to the negative (-) battery terminal.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
R5-7 (IGB) - Body ground	Ignition switch ON	11 to 14 V

(d) Connect the forward recognition camera connector.

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

4.	CHECK HARNESS AND CONNECTOR (FORWARD RECOGNITION CAMERA - BODY GROUND)

(a) Disconnect the forward recognition camera connector.

*a	Front view of wire harness connector (to Forward Recognition Camera)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
R5-10 (GND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY))

(a) Disconnect the millimeter wave radar sensor assembly connector.

*a	Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A2-8 (IGB) - Body ground	Ignition switch ON	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

6.	CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - BODY GROUND)

(a) Disconnect the millimeter wave radar sensor assembly connector.

*a	Front view of wire harness connector (to Millimeter Wave Radar Sensor Assembly)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A2-1 (SGND) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	REPLACE FORWARD RECOGNITION CAMERA

(a) Replace the forward recognition camera.

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(b) Perform forward recognition axis adjustment.

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8.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

Click here

Body Electrical > Pre-Collision 2 > Clear DTCs

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

Click here

Body Electrical > Pre-Collision 2 > Trouble Codes

Result	Proceed to
DTC U023A is not output	A
DTC U023A is output	B

END (FORWARD RECOGNITION CAMERA WAS DEFECTIVE)

9.	REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

(a) Replace the millimeter wave radar sensor assembly.

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(b) Adjust the millimeter wave radar sensor assembly.

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10.	CLEAR DTC (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

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Body Electrical > Pre-Collision 2 > Clear DTCs

END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

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