Symptom Procedure

Daytime running light function does not illuminate.

Daytime Running Light Circuit:

Connectors:

CIRCUIT OPERATION
Turn the ignition switch to the ON" position, and battery positive voltage will be applied from the daytime running light-ECU to headlight (high beam)

TECHNICAL DESCRIPTION (COMMENT)
The cause may be a faulty daytime running light circuit or a faulty daytime running light- ECU.

TROUBLESHOOTING HINTS
- Malfunction of the daytime running light-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set

STEP 1. Check the daytime running light-ECU power supply (battery) circuit at the daytime running light-ECU A-26.
1. Disconnect the daytime running light connector A-26.




2. Measure the voltage between terminal 1 and ground.

Q: Is the voltage 12 volts (battery positive voltage) between terminal 1 and ground?

YES: Go to Step 5.
NO: Go to Step 2.




STEP 2. Check the daytime running light-ECU connector A-26 for damage.

Q: Is daytime running light-ECU connector A-26 in good condition?

YES: Go to Step 3
NO: Repair or replace it. Refer to Harness Connector Inspection. The speedometer should work normally.




STEP 3. Check the harness wires between daytime running light-ECU connector A-26 and battery.

Q: Are the harness wires between daytime running light-ECU connector A-26 and battery in good condition?

YES: Go to step 4.
NO: Repair or replace it. Refer to Harness Connector Inspection.

STEP 4. Check the daytime running light-ECU power supply circuit (IG2) at the daytime running light-ECU A-26.
1. Disconnect the daytime running light-ECU.
2. Turn the ignition switch "ON" position.




3. Measure the resistance between terminal 2 and ground.

Q: Is the voltage 12 volts (battery positive voltage) between terminal 2 and ground?

YES: Go to Step 7.
NO: Go to Step 5.




STEP 5. Check the connector between daytime running light-ECU connector A-26 and ignition switch for damage.

Q: Are connector between daytime running light-ECU connector A-26 and ignition switch in good condition?

YES: Go to Step 6.
NO: Repair or replace it. Refer to Harness Connector Inspection.













STEP 6. Check the harness wire between daytime running light-ECU connector A-26 and ignition switch.

NOTE: After checking intermediate connector C-209 and junction block connector C-301 and C-310, check the wires. If intermediate connector C-209 and junction block connector C-301 and C-310 are damaged, repair or replace them. Refer to Harness Connector Inspection.

Q: Are the harness wire between daytime running light- ECU connector A-26 and ignition switch in good condition?

YES: Go to Step 7.
NO: Repair or replace it. Refer to Harness Connector Inspection.




STEP 7. Check the daytime running light ground circuit at the daytime running light connector A-26.
1. Disconnect the daytime running light connector A-26.




2. Measure the resistance between terminal 6 and ground.

Q: Is the resistance less than 2 ohms?

YES: Go to Step 9.
NO: Go to Step 8.




STEP 8. Check the harness wire between daytime running light-ECU connector A-26 and ground.

Q: Are harness wire between daytime running light-ECU connector A-26 and ground in good condition?

YES: Go to Step 9.
NO: Repair or replace it. Refer to Harness Connector Inspection.







STEP 9. Check the connector between daytime running light-ECU connector A-26 and headlight (RH) connector A-34 for damage.

NOTE: After checking intermediate connector C-05, check the wires. If intermediate connector C-05 is damaged, repair or replace it. Refer to Harness Connector Inspection.

Q: Are connector between daytime running light-ECU connector A-26 and headlight (RH) connector A-34 in good condition?

YES: Go to Step 10.
NO: Repair or replace it. Refer to Harness Connector Inspection.







STEP 10. Check the harness wire between daytime running light-ECU connector A-26 and headlight (RH) connector A-34.

NOTE: After checking intermediate connector C-05, check the wires. If intermediate connector C-05 is damaged, repair or replace it. Refer to Harness Connector Inspection.

Q: Are harness wire between daytime running light-ECU connector A-26 and headlight (RH) connector A-34 in good condition?

YES: Go to Step 11
NO: repair or replace it. Refer to Harness Connector Inspection.




STEP 11. Check the connector between daytime running light-ECU connector A-26 and headlight (LH) connector A-24 for damage.

Q: Are connector between daytime running light-ECU connector A-26 and headlight (LH) connector A-24 in good condition?

YES: Go to Step 12.
NO: Repair or replace it. Refer to Harness Connector Inspection.




STEP 12. Check the harness wire between daytime running light-ECU connector A-26 and headlight (LH) connector A-24.

Q: Are harness wire between daytime running light-ECU connector A-26 and headlight (LH) connector A-24 in good condition?

YES: Replace the daytime running light-ECU.
NO: repair or replace it. Refer to Harness Connector Inspection.