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Home >> Mitsubishi >> 2005 >> 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.

Fog Lights Circuit Part 1:




Fog Lights Circuit Part 2:






NOTE: This troubleshooting procedure requires the use of scan tool MB991958 and SWS monitor kit MB991813. For details on how to use the SWS monitor, refer to "How to use SWS monitor." How To Use SWS Monitor

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
- The fog light relay may be defective.
- The fog light switch may be defective.
- The front-ECU may be defective.
- The ETACS-ECU may be defective.
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector.

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles communication interface (V.C.I.)
- 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. Verify 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 MB991910 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 table.

Q: Does the scan tool MB991958 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.
Normal condition is not displayed for "IG SW (IG1)": Refer to Inspection Procedure O-2 "ETACS-ECU does not receive a signal from the ignition switch (IG1)."
Normal condition is not displayed for "F.FOG LIGHT": Refer to Inspection Procedure O-3 "ETACS-ECU does not receive a signal from the fog light switch."




STEP 3. Check fog light relay connector A-04X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

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

YES: Go to Step 4.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify that the fog lights illuminate normally.







STEP 4. Check the fog light relay.

Q: Is the fog light relay in good condition?

YES: Go to Step 5.

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

STEP 5. Check the battery power supply circuit to the fog light relay. Measure the voltage at fog light relay connector A-04X.




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




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

Q: Is the measured voltage approximately 12 volts (battery positive voltage)?

YES: Go to Step 7.

NO: Go to Step 6.




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 is necessary and testing is complete.

NO: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the fog lights illuminate normally.




STEP 7. Check front-ECU connector A-10X for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is front-ECU connector A-10X in good condition?

YES: Go to Step 8.

NO: Repair or replace the damaged component(s). Refer to Harness Connector Inspection. Verify 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: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the fog lights illuminate normally.










STEP 9. Check fog light connectors A-28, A-31 and combination meter connector C-43 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are 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 damaged component(s). Refer to Harness Connector Inspection. Verify 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 A-06 and C-89 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connectors A-06 or C-89 are damaged, repair or replace the damaged component(s) 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: The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. Verify that the fog lights illuminate normally.

STEP 11. Replacement of ECU

1. Replace the front-ECU.
2. Verify that the fog lights illuminate normally.

Q: Do the fog lights illuminate normally?

YES: No action is necessary and testing is complete.

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