Did you perform the Headlight System Check?

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Go to Step 2

Go to Headlight System Check

Use the scan tool in order to read the current body control module (BCM) diagnostic trouble codes (DTCs).

Is DTC B2575, B2577, or B600 set as a current code?

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Go to Diagnostic System Check - Body Control System in Body Control System

Go to Step 3

1. Place the headlamp switch in the HEAD position.
2. Place the multifunction switch in the LOW BEAM position.
3. Use a test lamp in order to backprobe between the following components:

•	Connector C211 terminal E12

•

Ground

Does the test lamp light?

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Go to Step 5

Go to Step 4

Locate and repair an open in CKT 525 (YEL) between the following components:

Is the repair complete?

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Go to Headlight System Check

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Replace the multifunction switch.

Is the repair complete?

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Go to Headlight System Check

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Did you perform the Headlight System Check?

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Go to Step 2

Go to Headlight System Check

1. Disconnect the low beam relay.
2. Connect a J 39200 digital multimeter (DMM) between cavity 30 at the low beam relay and ground.

Does the voltage equal the specified value?

B+

Go to Step 3

Go to Step 20

1. Connect a test lamp between low beam relay cavity 85 and ground.
2. Turn the headlamp switch to the HEAD position.

Does the test lamp light?

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Go to Step 4

Go to Step 10

1. Temporarily remove the RT HI fuse.
2. Remove the low beam relay.
3. Connect a J 39200 DMM from UBEC cavity 86 to ground.
4. Test for continuity.

Is the resistance less than the specified value?

1 ohms

Go to Step 5

Go to Step 9

1. Re-install the low beam relay.
2. Re-install the RT HI fuse.
3. Turn the headlamp switch to the HEAD position.
4. Connect a test lamp between the following components:

•

Ground

•	Each exposed test point on the back of both the RT LOW and LT LOW fuses

Does the test lamp light on at least one test point on each fuse?

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Go to Step 26

Go to Step 6

1. Disconnect the low beam relay.
2. Connect a J 39200 DMM between the following components:

•

Cavity 87

•	Each exposed test point on the back of both the RT LOW and LT LOW fuses

Is the resistance less than or equal to the specified value at each fuse?

1 ohms

Go to Step 7

Go to Step 8

Replace the low beam relay.

Is the repair complete?

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Go to Headlight System Check

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Replace the underhood bussed electrical center (UBEC).

Is the repair complete?

--

Go to Headlight System Check

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Locate and repair the open in CKT 350 (BLK), in the terminals or in the UBEC.

Is the repair complete?

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Go to Headlight System Check

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Connect a test lamp between the following components:

Does the test lamp light at both test points?

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Go to Step 14

Go to Step 11

Does the test lamp light at either test point?

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Go to Step 12

Go to Step 13

1. Locate and repair the short to ground in the circuit between the following components:

•	The HDLP SW fuse

•	The low beam relay

2. Replace the HDLP SW fuse.

Is the repair complete?

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Go to Headlight System Check

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Locate and repair the open in power feed to HDLP SW fuse. Refer to Power Distribution Schematics in Wiring Systems.

Is the repair complete?

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Go to Headlight System Check

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1. Disconnect the headlamp switch.
2. Connect a fused jumper between the following components:

•	CKT 1940 (ORN) cavity D

•	CKT 103 (WHT) cavity C at the headlamp switch connector

Do the headlamps turn ON?

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Go to Step 15

Go to Step 16

Replace the headlamp switch.

Is the repair complete?

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Go to Headlight System Check

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Connect a test lamp between ground and CKT 1940 (ORN) for cavity D at the headlamp switch connector.

Does the test lamp light?

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Go to Step 17

Go to Step 19

Test CKT 103 (WHT) for an open circuit.

Is there an open present in CKT 103 (WHT)?

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Go to Step 18

Go to Step 9

Locate and repair the open in CKT 103 (WHT).

Is the repair complete?

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Go to Headlight System Check

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Locate and repair the open in CKT 1940.

Is the repair complete?

--

Go to Headlight System Check

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Inspect the charging system. Refer to Charging System Check in Engine Electrical.

Is the charging system functioning properly?

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Go to Step 22

Go to Step 21

Repair the charging system.

Is the repair complete?

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Go to Headlight System Check

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1. Connect test leads and test lead adapters to the J 39200 .
2. Record this value and subtract it from all resistance readings. If the meter you are using has a zeroing function, zero the meter.
3. Disconnect the battery positive cable.
4. Connect a J 39200 between the following components:

•	The battery positive cable

•	Cavity 30 at the low beam relay.

Is the resistance less than or equal to the specified value?

1 ohms

Go to Step 24

Go to Step 23

1. Locate and repair high resistance between the following components:

•	The battery positive cable

•	The low beam relay

2. If all connections are clean and tight, replace the underhood bussed electrical center (UBEC).

Is the repair complete?

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Go to Headlight System Check

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1. Reconnect the battery positive cable.
2. Reconnect the low beam relay.
3. Turn the headlamp switch to the HEAD position.

Do the HID headlamps illuminate?

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Go to Headlight System Check

Go to Step 25

1. Remove the underhood bussed electrical center (UBEC) and hold down the bolts.
2. Flip the UBEC over.
3. Disconnect connector C4.
4. Inspect the cavities and terminals for damaged or corroded connections.

Are the connections OK?

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Go to Step 26

Go to Step 27

Repair the poor connection(s) in connector C4.

Is the repair complete?

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Go to Headlight System Check

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1. Remove the cover from connector C4.
2. Reconnect the connector C4 to UBEC.
3. Connect a J 39200 between the following components:

•	Cavity 87 at the low beam relay socket

•	Terminal B2 on the underside of the UBEC at connector C4.

Does the resistance equal the specified value?

1.0 ohms (or negligible)

Go to Step 31

Go to Step 28

Inspect for a high resistance in the UBEC connection.

Is the connection OK?

--

Go to Step 30

Go to Step 29

Repair the high resistance in the UBEC connection.

Is the repair complete?

--

Go to Headlight System Check

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Replace the UBEC.

Is the repair complete?

--

Go to Headlight System Check

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Connect a J 39200 DMM between the following components:

Does the resistance equal the specified value?

1.0 ohms (or negligible)

Go to Step 35

Go to Step 32

Inspect for a high resistance in the UBEC connection.

Is the connection OK?

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Go to Step 34

Go to Step 33

Repair the high resistance in the UBEC connection.

Is the repair complete?

--

Go to Headlight System Check

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Replace the UBEC.

Is the repair complete?

--

Go to Headlight System Check

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1. Replace the low beam relay.
2. Turn the headlamp switch to the HEAD position.

Do the HID headlamps illuminate?

--

Go to Headlight System Check

Go to Step 36

At this point, you have inspected every component and wiring path that is common to both HID headlamps.

You have inspected the system for an open or high resistance in the following components:

Since this symptom is for both HID, inoperative, it is unlikely that both of each of the following components is defective:

This possibility does exist, however.

Is all of the above statement true?

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Go to Headlamps Inoperative - One Lamp

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