Inspection Procedure P-20: No photo sensor signal is received.


caution Whenever the ECU is replaced, ensure that the input signal circuit is normal.


COMMENTS ON TROUBLE SYMPTOM
Input signal from the photo sensor is used to operate the auto lamp function. If the signal is abnormal, the auto lamp function will not work normally.

POSSIBLE CAUSES

  • Malfunction of photo sensor
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Connector check: C-03 photo sensor connector and C-220 ETACS-ECU connector.


Q. Is the check result normal?

Go to Step 2.

Repair the defective connector.

Step 2. Check the wiring harness from C-03 photo sensor connector terminal No.3, 4, 5 to C-220 ETACS-ECU connector terminal No.27, 28, 26.



  • Check the sensor line for open circuit.

Q. Is the check result normal?

Go to Step 3.

Repair the wiring harness.

Step 3. ETACS ANALOG data by using the SWS monitor.

  • Vary the illumination intensity of the photo sensor.
Item No.
 Item name
 Normal condition
Item 01
 PHTO SNR VOLT
 The voltage changes within a range of 0.68 to 3.8 V.
OK: Normal condition is displayed.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 4.

Step 4. Replacing the photo sensor
(1)Replace the photo sensor (Refer to Group 55 - Photo sensor and inter temperature sensor ).
(2)Check that the signals from the photo sensor are received.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.