Inspection Procedure 7: Daytime Running Lamp Function does not Work Normally. <Using SWS Monitor>


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.






COMMENTS ON TROUBLE SYMPTOM
If the daytime running lamp function is not operating normally the ETACS-ECU power circuit may be defective or the ETACS-ECU may be defective.

PROBABLE CAUSES

  • The ETACS-ECU may be defective
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Check that the headlamps operate.
Do the low-beam headlamps illuminate when the lighting switch is turned to the HEAD position?

Q. Is the check result normal?
Go to Step 2.
First, repair the headlamps. Refer to Inspection Procedure 1 "The low-beam headlamps do not illuminate normally ."

STEP 2. SWS monitor data list.
Check the input signals below, which are related to the interior lamp automatic-shutdown function.
<Selected item> ETACS ECU
  • Ignition switch: ON
Item No.
 Item name
 Normal condition
Item 30
 IG SW(IG1)
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?
Go to Step 3.
Refer to ETACS - Input Signal Chart .

STEP 3. ECU check by using the SWS monitor.
Check that the power supply and earth lines to the ETACS-ECU and the SWS communication lines are normal.

  • Ignition switch: OFF
ECUS TO BE CHECKED
  • ETACS ECU
OK: "OK" is displayed on the "ETACS ECU" menu.

Q. Is the check result normal?
Go to Step 4.
Refer to GROUP 54C - Trouble Symptom Chart .

STEP 4. ETACS switch data by using the SWS monitor
Check the ETACS-ECU signal related to the daytime running lamp operation.
Item No.
 Item name
 Normal condition
Item 35
 Daytime running lamp switch
 ON
OK: Normal condition is displayed.

Q. Is the check result normal?
Replace the ETACS-ECU.
Go to Step 5.

STEP 5. Connector check: D-420 ETACS-ECU connector.

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector.

STEP 6. Resistance measurement at the D-420 ETACS-ECU connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Check the resistance between the ETACS-ECU connector and body earth.

  • Resistance between D-420 ETACS-ECU connector terminal No.64 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Replace the ETACS-ECU.
Go to Step 7.

STEP 7. Check the wiring harness from D-420 ETACS-ECU connector terminal No.64 to body earth.
note Prior to the wiring harness inspection, check jumper connector D-01, and repair if necessary.

  • Check the earth wires for open circuit.

Q. Is the check result normal?
Replace the ETACS-ECU.
Repair the wiring harness.