Inspection Procedure 1: The daytime running lamps do not illuminate normally.


caution Whenever the ECU is replaced, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

COMMENTS ON TROUBLE SYMPTOM


If the daytime running lamp function is not operating normally, the ETACS-ECU power circuit may be defective, daytime running lamp relay may be defective or the ETACS-ECU may be defective.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III diagnosis code.


When the ignition switch is turned to the "LOCK" (OFF) position, check that the ETACS-ECU does not set the diagnosis code.

Q. Is the diagnosis code set?

Refer to diagnosis code chart .

Go to Step 2.

STEP 2. M.U.T.-III data list


Check the input signals below, which are related to the daytime running lamp function.

Item No.
 Item name
 Normal condition
Item 254
 IG voltage
 System voltage
OK: Normal condition is displayed.

Q. Is the check result normal?

Go to Step 3.

Refer to inspection procedure 2 "The ignition switch (IG1) signal is not received ."

STEP 3. Check the daytime running lamp relay


Q. Is the check result normal?

Go to Step 4.

Replace the daytime running lamp relay.

STEP 4. Voltage measurement at daytime running lamp relay connector (power supply terminals).


(1)Remove the daytime running lamp relay, and measure at the relay box side.
(2)Check the voltage between the daytime running lamp relay connector (power supply terminals) and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 6.

Go to Step 5.

STEP 5. Check of open circuit in power supply lines between the daytime running lamp relay connector and fusible link.


Q. Is the check result normal?

Go to Step 9.

Repair the connector(s) or wiring harness.

STEP 6. Check of open circuit in IDRL line between the daytime running lamp relay connector and ETACS-ECU connector.


Q. Is the check result normal?

Go to Step 7.

Repair the connector(s) or wiring harness.

STEP 7. Check of open circuit in output line between the daytime running lamp relay connector and daytime running lamp (LH), daytime running lamp (RH) connector.


Q. Is the check result normal?

Go to Step 8.

Repair the connector(s) or wiring harness.

STEP 8. Check of open circuit in earth line between the daytime running lamp (LH), daytime running lamp (RH) connector and body earth.


Q. Is the check result normal?

Go to Step 9.

Repair the connector(s) or wiring harness.

STEP 9. Retest the system.


Check that the daytime running lamp function works 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.