Inspection Procedure P-19: The hood switch signal is not received.


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


COMMENTS ON TROUBLE SYMPTOM
Input signal from the hood switch is used to operate the security alarm. If the signal is abnormal, the security alarm will not work.

POSSIBLE CAUSES

  • Malfunction of the hood switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Connector check: A-42 hood switch connector.

Q. Is the check result normal?

Go to Step 2.

Repair the defective connector.

Step 2. Check the hood switch
Refer to GROUP 42 - Body .

Q. Is the check result normal?
Go to Step 3.
Replace the hood switch.

STEP 3. Resistance measurement at the A-42 hood switch connector.

(1)Disconnect the connector, and measure at the wiring harness side.

(2)Resistance between A-42 hood switch connector terminal No.2 and body earth
OK: 2 Ω or less

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

Step 4. Check the wiring harness between A-42 hood switch connector terminal No.2 to body earth.


  • Check the earth wires for open circuit.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

Step 5. Connector check: C-219 ETACS-ECU connector

Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

Step 6. Check the wiring harness from A-42 hood switch terminal No.1 to C-219 ETACS-ECUconnector terminal No.21.



note Prior to the wiring harness inspection, check intermediate connector C-134, and repair if necessary.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.

Step 7. Retest the system.
Check that the hood switch signal is received normally.

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.