Inspection Procedure H-1: The front fog lamps do not illuminate normally.


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.


OPERATION


The ETACS-ECU operates this function in accordance with the input signals below.

If the front fog lamps (both right and left) do not illuminate, these input signal circuit(s) or the ETACS-ECU may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code.
Check that ETACS-ECU sets a diagnosis code.

Q. Is the diagnosis code set?
Refer to diagnosis code chart .
Go to Step 2.

STEP 2. Check that the tail lamps and headlamps operate.
Check that the tail lamps and headlamps illuminate normally.

Q. Is the check result normal?
Go to Step 3.
Check the tail lamps and the headlamps (Refer to trouble symptom chart ).

STEP 3. M.U.T.-III data list
Check the input signals below, which are related to the front fog lamps.
(1)Turn the ignition switch to the "ON" position.
(2)Operate the front fog lamp switch.
Item No.
 Item name
 Normal condition
23
 Front fog lamp switch
 ON
30
 Ignition switch (IG1)
 ON
OK: Normal conditions are displayed for all the items.

Q. Is the check result normal?
YES <All the signals are received normally.> : Go to Step 4.
NO <The ignition switch (IG1) signal is not received.> : Refer to inspection procedure J-3 "The ignition switch (IG1) signal is not received ."
NO <The front fog lamp switch signal is not received.> : Refer to inspection procedure J-5 "The front fog lamp switch signal is not received ."

STEP 4. M.U.T.-III actuator test
Perform the actuator test for the ETACS-ECU, and check that the front fog lamps illuminate normally.

  • Item 33: Front fog lamp: OFF
  • Item 34: Front fog lamp: ON

Q. Is the check result normal?
Go to Step 11.
Go to Step 5.

STEP 5. Connector check: B-215 front fog lamp relay connector.


Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Check the front fog lamp relay.
Refer to GROUP 54A - Front fog lamp .

Q. Is the check result normal?
Go to Step 7.
Replace the front fog lamp relay.

STEP 7. Voltage measurement at the B-215 front fog lamp relay connector.


(1)Remove the front fog lamp relay, and measure at the relay box side.

(2)Check the voltage between the front fog lamp relay connector and body earth.

  • Voltage between B-215 front fog lamp relay connector terminal No.1 and body earth
  • Voltage between B-215 front fog lamp relay connector terminal No.3 and body earth
OK: System voltage

Q. Is the check result normal?

Go to Step 9.

Go to Step 8.

STEP 8. Check the wiring harness from B-215 front fog lamp relay connector terminal Nos. 1 and 2 to the fusible link (6).



note Prior to the wiring harness inspection, check the junction block connector B-208, and repair if necessary.

  • Check the power supply line from the fusible link (6) for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

STEP 9. Connector check: B-233 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 10.

Repair the defective connector.

STEP 10. Check the wiring harness between B-215 front fog lamp relay connector terminal No.2 and B-233 ETACS-ECU connector terminal No.67.




note Prior to the wiring harness inspection, check the junction block connector B-231, and repair if necessary.

  • Check the output lines for open circuit and short circuit.

Q. Is the check result normal?

Go to Step 11.

Repair the wiring harness.

STEP 11. Retest the system.
Check that the front fog lamps illuminate normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU. Then perform the variant coding and write the VIN data (Refer to GROUP 00, Precautions Before Service - How to Perform Variant Coding ).