Code No.21 Height Sensor Abnormality (Rear)


caution Before replacing the ECU, ensure that the communication circuit is normal.












TROUBLE JUDGMENT



COMMENTS ON TROUBLE SYMPTOM



PROBABLE CAUSES



  • Malfunction of the rear height sensor
  • Malfunction of the headlamp automatic levelling ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE


STEP 1. Connector check: D-117 rear height sensor connector


Q. Is the check result normal?





STEP 2. Rear height sensor check



Q. Is the check result normal?





STEP 3. Connector check: C-112 headlamp automatic levelling ECU connector


Q. Is the check result normal?





STEP 4. Wiring harness check between the D-117 rear height sensor connector terminal No. 1/2/3 and the C-112 headlamp automatic levelling ECU connector terminal No. 16/18/20.



  • Check the power supply lines, earth lines and communication lines for open circuit.
note Before the wiring harness check, check the intermediate connectors C-131 and D-116, and then repair that if necessary.

Q. Is the check result normal?





STEP 5. Check whether the diagnosis code is reset.


Q. Is diagnosis code No.21 set?