Pre-Collision System

PRE-COLLISION: PRE-COLLISION SYSTEM: U0235: Lost Communication with Cruise Control Front Distance Range Sensor
U0235 - Lost Communication with Cruise Control Front Distance Range Sensor

DESCRIPTION

The driving support ECU assembly sends information on steering angle and steering direction to the millimeter wave radar sensor. The millimeter wave radar sensor then sends information on the presence, distance, and relative speed of objects ahead to the driving support ECU assembly. The driving support ECU assembly sends this information to the power management control ECU and performs cruise control.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the millimeter wave radar sensor with a new one, make sure to perform Adjust Millimeter Wave Radar Sensor Assembly Adjustments.
* Confirm that the connector is securely connected, as a partially connected connector is suspected for the cause of this DTC.

PROCEDURE

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

(a) Disconnect the L60 driving support ECU assembly connector.

(b) Disconnect the A2 millimeter wave radar sensor connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU - MILLIMETER WAVE RADAR SENSOR)
OK -- Continue to next step.

2. CHECK DRIVING SUPPORT ECU ASSEMBLY (B CIRCUIT)

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





Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (B CIRCUIT)
OK -- Continue to next step.

3. CHECK MILLIMETER WAVE RADAR SENSOR (IGB CIRCUIT)

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





Standard Voltage:





Text in Illustration





(b) Reconnect the A2 millimeter wave radar sensor connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IGB CIRCUIT)
OK -- Continue to next step.

4. CHECK DRIVING SUPPORT ECU ASSEMBLY (LRDD OUTPUT VOLTAGE)

(a) 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 assembly Removal.

NEXT -- Continue to next step.

6. CHECK DTC OUTPUT

(a) Clear the DTCs Pre-Collision System.

(b) Turn the cruise control main switch on.

(c) Check if the same DTC is output Pre-Collision System.

Result:





B -- REPLACE MILLIMETER WAVE RADAR SENSOR Removal

A -- END (DRIVING SUPPORT ECU ASSEMBLY WAS DEFECTIVE)