Check UART Communication Line Circuit

AUTOMATIC DRIVE POSITIONER


Check UART Communication Line Circuit

1.CHECK UART LINE HARNESS
1. Turn ignition switch OFF.





2. Disconnect driver seat control unit and automatic drive positioner control unit connector.
3. Check continuity between driver seat control unit connector and automatic drive positioner connector.





4. Check continuity between driver seat control unit connector and ground.





OK or NG
OK - GO TO 2.
NG - Repair or replace harness.
2.CHECK UART LINE INPUT/OUTPUT SIGNAL 1
1. Connect driver seat control unit and automatic drive positioner control unit connector.
2. Turn ignition switch ON.





3. Check signal between driver seat control unit connector and ground, with oscilloscope.





OK or NG
OK - GO TO 3.
NG - Check the following.
- When voltage wave form does not appear with a constant voltage (approx. 5V), replace driver seat control unit.
- When voltage wave form does not appear with a constant voltage (approx. 0V), replace automatic drive positioner control unit.
3.CHECK UART LINE INPUT/OUTPUT SIGNAL 2





Check signal between automatic drive positioner control unit connector and ground, with oscilloscope.





OK or NG
OK - GO TO 4.
NG - Check the following.
- When voltage wave form does not appear with a constant voltage (approx. 5V), replace automatic drive positioner control unit.
- When voltage wave form does not appear with a constant voltage (approx. 0V), replace driver seat control unit.
4.CHECK DRIVER SEAT CONTROL UNIT
Does the automatic drive positioner operate when the driver seat control unit is exchanged?
OK or NG
OK - Replace driver seat control unit.
NG - Replace automatic drive positioner control unit.