Dynamic Radar Cruise Control System

CRUISE CONTROL: DYNAMIC RADAR CRUISE CONTROL SYSTEM: U0235-737: Communication Error from Radar Sensor to Distance Control ECU

DTC U0235-737 - Communication Error from Radar Sensor to Distance Control ECU

DESCRIPTION

The millimeter wave radar sensor and distance control ECU transmit the data for general vehicle control and diagnosis function along the communication line. The distance control ECU determines the presumed R information based on the signal from the steering wheel and yaw rate sensor. The distance control ECU transmits the current vehicle speed and presumed R information to the millimeter wave radar sensor.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- When the distance control ECU is 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 WIRE HARNESS (DISTANCE CONTROL ECU - MILLIMETER WAVE RADAR
SENSOR)




(a) Disconnect the K13 ECU connector.
(b) Disconnect the B8 sensor connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2.
CHECK DISTANCE CONTROL ECU




(a) Measure the voltage of the connector.
Standard voltage :






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




(a) Check the signal waveform between terminals LRDD (K13-22) and SGND (K13-10) of the distance control ECU connector.
OK:
A waveform similar to that in the illustration on the left is output.
- Gauge set: 2 V/DIV., 10 msec./DIV.
- Condition: Power switch on (IG)

NG -- REPLACE MILLIMETER WAVE RADAR SENSOR
OK -- REPLACE DISTANCE CONTROL ECU
4. REPLACE MILLIMETER WAVE RADAR SENSOR
(a) Replace the millimeter wave radar sensor.
(b) Adjust the millimeter wave radar sensor Adjustments.
NEXT -- Continue to next step.
5. CHECK DTC OUTPUT
(a) Clear the DTC.
(b) Turn the cruise control main switch on.
(c) Drive the vehicle at the required speed (40 km/h (25 mph) or higher).
(d) Check if the same DTC is recorded.
Result:






B -- REPLACE DISTANCE CONTROL ECU
A -- END (INTERMITTENT PROBLEM IS PRESENT)