Inspection Procedure O-5

Fog Light Switch Input Circuit:

CIRCUIT OPERATION
The ETACS-ECU operates the fog lights according to the input signal from the fog light switch.

TECHNICAL DESCRIPTION (COMMENT)
The fog lights will not work normally if the fog light switch input signal is an error.

TROUBLESHOOTING HINTS
- Malfunction of the fog light switch
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS
Required Special Tools:
MB991223: Test Harness Set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness







STEP 1. Check the fog light switch.
If the hazard warning light switch is damaged, repair it. The fog light switch input signal should be able to be checked and the fog lights should work normally.
If the fog light switch is in good condition, go to Step 2.




STEP 2. Check the fog light switch ground circuit at the fog light switch connector C-76.
1. Disconnect the fog light switch connector C-76 and measure at the harness side.
2. Resistance between terminal 7 and ground.
- Should be less than 2 Ohms.
If open circuit, go to Step 3.
If less than 2 Ohms. go to Step 5.




STEP 3. Check the fog light switch connector C-76 for damage.
If the fog light switch connector C-76 is damaged, repair or replace it. Refer to Harness Connector Inspection.
The fog light switch input signal should be able to be checked and the fog light should work normally.
If the connector is in good condition, go to Step 4.




STEP 4. Check the harness wires between fog light switch connector C-76 and ground.

NOTE: After checking joint connector C-78, check the wires. If joint connector C-78 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between fog light switch connector C-76 and ground are damaged, repair them.
The fog light switch input signal should be able to be checked and the fog lights should work normally.







STEP 5. Check the fog light switch connector C-76 and ETACS-ECU connector C-111 for damage.
If the fog light switch connector C-76 and ETACS-ECU connector C-111 are damaged, repair or replace them. Refer to Harness Connector Inspection. The fog light switch input signal should be able to be checked and the fog lights should work normally.
If the connectors are in good condition, go to Step 6.







STEP 6. Check the harness wire between fog light switch connector C-76 and ETACS-ECU connector C-111.
If the harness wire between fog light switch connector C-76 and ETACS-ECU connector C-111 is damaged, repair it. The fog light switch input signal should be able to be checked and the fog lights should work normally.
If the harness wire is in good condition, replace the ETACS-ECU.
The fog light switch input signal should be able to be checked and the fog lights should work normally.