U1102

CRUISE CONTROL: DYNAMIC LASER CRUISE CONTROL SYSTEM: U1102: Lost Communication with Radar Sensor

DTC U1102 - Lost Communication with Radar Sensor

DESCRIPTION

The laser sensor and distance control ECU (cruise control ECU) transmit the data for general vehicle control and diagnosis function along the communication line. The distance control ECU (cruise control ECU) determines the curve radius information based on signals from the steering wheel and yaw rate sensor. The distance control ECU (cruise control ECU) transmits the current vehicle speed and curve radius information to the laser sensor.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- When the distance control ECU is replaced with a new one, initialization must be performed. Adjustments
- When the laser sensor is replaced with a new one, adjustment of the laser sensor beam axis must be performed. Adjustments

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - LASER SENSOR)





(a) Disconnect the distance control ECU connector and laser sensor connector.
(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) Reconnect the distance control ECU connector.





(b) 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 LASER SENSOR





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










(b) Check the signal waveform between terminal LRRD (B9-4) of the laser sensor and body ground.
OK:
A waveform similar to that in the illustration on the left is output.
- Gauge set: 2 V/DIV., 5 ms./DIV.
- Condition: Ignition switch on

NG -- REPLACE LASER SENSOR
OK -- END (INTERMITTENT PROBLEM IS PRESENT)