Mazda 3 Service Manual: Discharge Headlight System Inspection

STEP

INSPECTION

ACTION

1

• Disconnect the negative battery cable..

• Disconnect the discharge headlight control module connector.

• Connect the negative battery cable..

• Turn the light switch to the HEAD position.

• Measure the voltage at discharge headlight control module connector (harness-side) terminal A.

• Is the voltage approx. 12 V

  ?

Yes

Go to Step 6.

No

Go to the next step.

2

• Turn the light switch to the OFF position.

• Remove the H/L LO RH 15 A fuse or H/L LO LH 15 A fuse.

• Inspect the fuses.

• Are the fuses normal?

Yes

Go to the next step.

No

Replace the fuse.

3

• Remove the headlight relay (LO)..

• Inspect the headlight relay (LO)..

• Is the headlight relay (LO) normal?

Yes

Go to the next step.

No

Replace the headlight relay (LO)..

4

• Inspect the light switch..

• Is the light switch normal?

Yes

Go to the next step.

No

Replace the light switch..

5

• Disconnect the negative battery cable..

• Inspect for continuity between the following terminals:

• Positive battery—headlight relay (LO) terminal D

• H/L LO RH 15 A fuse—discharge headlight control module terminal A

• H/L LO LH 15 A fuse—discharge headlight control module terminal A

• Are the wiring harnesses normal?

Yes

Go to the next step.

No

Replace the related wiring harness.

6

• Inspect the wiring harness between the discharge headlight control module terminal B and ground for the following:

• Short to power supply

• Open circuit

• Is the wiring harness normal?

Yes

Go to the next step.

No

Replace the related wiring harness.

7

• Install any other discharge headlight bulb..

• Connect the discharge headlight control module connector.

• Turn the light switch to the HEAD position.

• Does the headlight (low-beam) illuminate?

Yes

Replace the discharge headlight bulb..

No

Replace the discharge headlight control module..