INSPECTION PROCEDURE L-5: The headlamp automatic shutdown function does not work normally. <Except vehicles for Australia>

CAUTION

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

COMMENTS ON TROUBLE SYMPTOM

The ETACS-ECU operates this function in accordance with the input signals below.

Ignition switch (IG1)

Driver's door switch

Tail lamp switch

Headlamp switch

If this function does not work normally, these input signal circuit(s), the front-ECU or the ETACS-ECU may be defective. Note that this function can be disabled/enabled by the adjustment function (default setting; enabled).

POSSIBLE CAUSES

Malfunction of the driver's door switch

Malfunction of the front-ECU

Malfunction of the column switch

Malfunction of the ETACS-ECU

Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

Step 1. Check the adjustment function.

Check that the headlamp automatic shutdown function has been enabled by using the adjustment function.

Q: Is the check result normal?

YES: Go to Step 2

.
NO: Enable the headlamp automatic shutdown function by using the adjustment function. Refer to

Step 2. Check that the headlamps operate.

Check that the low-beam and high-beam headlamps work normally.

Q: Is the check result normal?

YES: Go to Step 3

.
NO: Repair the headlamps. Refer to trouble symptom chart

Step 3. Pulse check

Check the input signals below, which are related to the headlamp automatic shutdown function.

System switch	Check condition
Ignition switch (IG1)	When turned from ACC to ON
Driver's door switch	When the driver's door is opened
Tail lamp switch	When the lighting switch is turned to the TAIL position

OK: The MUT-II/III sounds or the voltmeter needle fluctuates.

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 P-2 "The ignition switch (IG1) signal is not received

."
The driver's door switch signal is not received.: Refer to Inspection Procedure P-4 "The driver's door switch signal is not received <LH drive vehicles>

." Refer to Inspection Procedure P-4 "The driver's door switch signal is not received <RH drive vehicles>

."
The tail lamp switch signal is not received.: Refer to Inspection Procedure P-5 "The column switch (lighting and turn-signal lamp switch) signal is not received

Step 4. Retest the system.

Replace the ETACS-ECU, and then check that the headlamp automatic shutdown function works normally.

Replace the ETACS-ECU.

Check that the headlamp automatic shutdown function works normally.

Q: Is the check result normal?

YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

).
NO: Replace the front-ECU.