Inspection Procedure H-2: The rear fog lamps do not illuminate normally. <COLT>


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.

  • Tail lamp switch
  • Headlamp switch
  • Rear fog lamp switch
If the rear fog lamps (both right and left) do not illuminate, these input signal circuit(s) or the ETACS-ECU may be defective.

PROBABLE CAUSES

  • Malfunction of the column switch
  • Malfunction of the rear fog lamp switch
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

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 rear fog lamps.

  • Ignition switch: ON
  • Rear fog lamp switch: ON
Item No.
 System switch
 Check condition
24
 Rear fog lamp switch
 ON
30
 Ignition switch (IG1)
 ON
OK: Normal conditions are displayed for all the items.

Q. Is the check result normal?
All the signals are received normally. : Go to Step 4.
The ignition switch (IG1) signal is not received. : Refer to inspection procedure J-3 "The ignition switch (IG1) signal is not received ."
The rear fog lamp switch signal is not received. : Refer to inspection procedure J-6 "The rear 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 rear fog lamps illuminate normally.

  • Item 35: Rear fog lamp: OFF
  • Item 36: Rear fog lamp: ON

Q. Is the check result normal?
Go to Step 16.
Go to Step 5.

STEP 5. Connector check: B-204 rear fog lamp relay connector.


Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

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

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

STEP 7. Voltage measurement at the B-204 rear fog lamp relay connector.


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

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

  • Voltage between B-204 rear fog lamp relay connector terminal No.1 and body earth
  • Voltage between B-204 rear 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-204 rear 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: E-01 rear fog lamp connector <LH drive vehicles> or E-04 rear fog lamp connector <RH drive vehicles>

Q. Is the check result normal?

Go to Step 10.

Repair the defective connector.

STEP 10. Check the bulbs of the rear fog lamps.
Check the bulb(s) of the defective lamp.

Q. Is the check result normal?
Go to Step 11.
Replace the bulb(s) of the defective lamp.

STEP 11. Resistance measurement at the E-01 rear fog lamp connector <LH drive vehicles> or E-04 rear fog lamp connector <RH drive vehicles>.

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


(2)Check the resistance between E-01 rear fog lamp relay connector <LH drive vehicles> terminal No.4 or E-04 rear fog lamp relay connector <RH drive vehicles> connector terminal No.2 and body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 13.

Go to Step 12.

STEP 12. Check the wiring harness from E-01 rear fog lamp connector <LH drive vehicles> terminal No.6 or E-04 rear fog lamp connector <RH drive vehicles> terminal No.1 to body earth.


  • Check the earth wires 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 13. Check the wiring harness from E-01 rear fog lamp connector <LH drive vehicles> terminal No.4 or E-04 rear fog lamp connector <RH drive vehicles> terminal No.3 to B-204 rear fog lamp relay connector terminal No.4.





note Prior to the wiring harness inspection, check junction block connector B-228, and repair if necessary.

  • Check the output lines for open circuit.

Q. Is the check result normal?

Go to Step 14.

Repair the wiring harness.

STEP 14. Connector check: B-232 ETACS-ECU connector


Q. Is the check result normal?

Go to Step 15.

Repair the defective connector.

STEP 15. Check the wiring harness between B-204 rear fog lamp relay connector terminal No.2 and B-232 ETACS-ECU connector terminal No.33.




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.

Q. Is the check result normal?

Go to Step 16.

Repair the wiring harness.

STEP 16. Retest the system.
Check that the rear 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 ).