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Home >> Mitsubishi >> 2004 >> Eclipse L4-2.4L SOHC >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Symptom Diagnostic Procedures >> L - Charts >> Inspection Procedure L-1

Inspection Procedure L-1

Fog Light: Fog Lights do not Illuminate when the Fog Light Switch is Turned On.

NOTE: This troubleshooting requires use of scan tool MB991958 and SWS monitor kit MB991862. For details of how to use the SWS monitor, refer to "How to use SWS monitor." How To Use SWS Monitor

Fog Lights Circuit Part 1:




Fog Lights Circuit Part 2:






CIRCUIT OPERATION
- The ETACS-ECU sends a fog light illumination request signal ("LIGHT ON" signal) to the front-ECU when the fog light switch is turned on while the headlights are illuminating at low beam.
- Then the front-ECU switches on its relay to illuminate the fog lights.

TECHNICAL DESCRIPTION (COMMENT)
If the headlights illuminate at low beam, the fog light relay, the fog light switch, the front-ECU or the ETACS-ECU may be defective.

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

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface
- MB991827: MUT-III USB cable
- MB991911: MUT-III Main harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness

STEP 1. Check the headlight (low beam) operation.

Q: Do the headlights illuminate at low beam normally?

YES: Go to Step 2.

NO: Refer to Inspection Procedure J-2 "Headlights (low-beam) do not illuminate normally."

STEP 2. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.
Set each switch to the following condition before checking input signal from the fog light switch:
- Ignition switch: ON
- Fog light switch: ON

NOTE: Turn the ignition switch to the "ON" position in order to disable the headlight automatic shutdown function.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. Connect special tool MB991911 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.







1. Connect the special tool. Refer to "How to connect SWS monitor." How to Connect SWS Monitor
2. Operate scan tool MB991958 according to the procedure below to display "F.FOG."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Function Diag."
f. Select "LIGHTING."
g. Select "F.FOG."




3. Check that normal conditions are displayed on the items described in the given table.

Q: Does the scan tool display the items "IG SW (IG1)" and "F.FOG LIGHT" as normal condition?

Normal conditions are displayed for all the items: Go to Step 3.

The scan tool does not show the respective normal condition for item "IG SW (IG1)": Refer to Inspection Procedure O-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."

The scan tool does not show the respective normal condition for item "F. FOG LIGHT": Refer to Inspection Procedure O-3 "ETACS-ECU does not receive a signal from the fog light switch."







STEP 3. Check the fog light relay.

Q: Is the fog light relay in good condition?

YES: Go to Step 4.

NO: Replace the fog light relay. Check that the fog lights illuminate normally.

STEP 4. Measure at fog light relay connector A-04X in order to the battery power supply to the fog light relay.




1. Disconnect fog light relay connector A-04X, and measure at the relay box side.




2. Measure the voltage between terminal 1, 2 and ground.
- The measured value should be approximately 12 volts (battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES: Go to Step 7.

NO: Go to Step 5.




STEP 5. Check fog light relay connector A-04X for damage.

Q: Are fog light relay connector A-04X in good condition?

YES: Go to Step 6.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the fog lights illuminate normally.




STEP 6. Check the wiring harness between fog light relay connector A-04X (terminals 1 and 2) and the battery.

Q: Is the wiring harness between fog light relay connector A-04X (terminals 1 and 2) and the battery in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. Check that the fog lights illuminate normally.




STEP 7. Check fog light relay connector A-04X and front-ECU connector A-10X for damage.

Q: Are fog light relay connector A-04X and front-ECU connector A-10X in good condition?

YES: Go to Step 8.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the fog lights illuminate normally.




STEP 8. Check the wiring harness between fog light relay connector A-04X (terminal 3) and front-ECU connector A-10X (terminal 1).

Q: Is the wiring harness between fog light relay connector A-04X (terminal 3) and front-ECU connector A-10X (terminal 1) in good condition?

YES: Go to Step 9.

NO: Repair the wiring harness. Check that the fog lights illuminate normally.













STEP 9. Check fog light relay connector A-04X, fog light connectors A-28, A-31 and combination meter connector C-43 for damage.

Q: Are fog light relay connector A-04X, fog light connectors A-28, A-31 and combination meter connector C-43 in good condition?

YES: Go to Step 10.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the fog lights illuminate normally.



















STEP 10. Check the wiring harnesses among fog light relay connector A-04X (terminal 4), fog light connectors A-28 (terminal 1), A-31 (terminal 1) and combination meter connector C-43 (terminal 13).

NOTE: Also check intermediate connectors C-06 and C-89. If intermediate connectors C-06 or C-89 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Are the wiring harnesses among fog light relay connector A-04X (terminal 4), fog light connectors A-28 (terminal 1), A-31 (terminal 1) and combination meter connector C-43 (terminal 13) in good condition?

YES: Go to Step 11.

NO: Repair the wiring harness. Check that the fog lights illuminate normally.

STEP 11. Replacement of ECU

1. Replace the front-ECU.
2. The fog lights should illuminate normally.

Q: Do the fog lights illuminate normally?

YES: There is no action to be taken.

NO: Replace the ETACS-ECU. The fog light should illuminate normally.
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