Pre-Collision System

PRE-COLLISION SYSTEM:

DTC U1102 - Lost Communication with Radar Sensor

DESCRIPTION

The millimeter wave radar sensor and distance control ECU transmit the data for general vehicle control and diagnosis function along the communication line.






INSPECTION PROCEDURE

NOTICE:
- When the distance control ECU and/or ECM are replaced with a new one, initialization must be performed Installation.
- When the millimeter wave radar sensor is replaced with a new one, adjustment of the radar sensor beam axis must be performed Adjustments.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - MILLIMETER WAVE RADAR SENSOR)





(a) Disconnect the distance control 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 DISTANCE CONTROL ECU





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






NG -- REPLACE DISTANCE CONTROL ECU
OK -- Continue to next step.
3. CHECK MILLIMETER WAVE RADAR SENSOR





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










(b) Check the signal waveform.






OK:
A waveform similar to that in the illustration on the left is output.
NG -- REPLACE MILLIMETER WAVE RADAR SENSOR
OK -- END (INTERMITTENT PROBLEM IS PRESENT)