U1102

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: U1102: Lost Communication with Radar Sensor
U1102 - Lost Communication with Radar Sensor

DESCRIPTION

The millimeter wave radar sensor and driving support ECU transmit the data for general vehicle control and diagnosis function along the communication line. The driving support ECU determines the curve radius information based on signals from the steering wheel and yaw rate and acceleration sensor. The driving support ECU transmits the current vehicle speed and curve radius information to the millimeter wave radar sensor.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When the millimeter wave radar sensor is replaced with a new one, adjustment of the radar sensor beam axis must be performed Adjustments.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - MILLIMETER WAVE RADAR SENSOR)

(a) Disconnect the driving support ECU and millimeter wave radar sensor connectors.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR POWER SOURCE CIRCUIT)

(a) Disconnect the millimeter wave radar sensor connector.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

(a) Disconnect the millimeter wave radar sensor connector.





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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK MILLIMETER WAVE RADAR SENSOR

(a) Disconnect the driving support ECU connector.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





Text in Illustration





NG -- REPLACE MILLIMETER WAVE RADAR SENSOR Removal
OK -- Continue to next step.

5. REPLACE DRIVING SUPPORT ECU

(a) Replace the driving support ECU Removal.

NEXT -- Continue to next step.

6. CHECK DTC OUTPUT

(a) Clear the DTCs Dynamic Radar Cruise Control System.

(b) Perform the following to make sure that the DTC detection conditions are met.

HINT
If the detection conditions are not met, the malfunction cannot be detected.

(1) Drive the vehicle at a speed of 50 km/h (30 mph) or more.

(2) Turn the cruise control main switch on.

(c) Check for DTCs Dynamic Radar Cruise Control System.

Result





B -- REPLACE MILLIMETER WAVE RADAR SENSOR Removal

A -- END