Replacing headlamp What are the steps to replace a headlamp that's out? The driver's side headlamp in front of the battery.

Did you think of taking to a qualified repair shop ? The headlamp switch is a input to the BCM - body control module , the BCM then energizes the low beam relay . Could have DTC'S - diagnostic trouble code's stored . Also with scanner can view input data from the switch to the BCM an control circuit from BCM to the low beam relay . You people an just replacing parts . lol Your not seeing the whole picture .Your best bet , take it to a qualified repair shop .

For low beam operation, battery positive voltage is applied at all times to the coil and switch side of the low beam relay in the underhood fuse block. Ground is applied at all times from G202 to the headlamp switch. When the headlamp switch is placed in the HEAD position, ground is applied to the headlamps ON signal circuit to the body control module (BCM). When either the headlamp switch is placed in the HEAD position or ALC is enabled, the BCM applies a ground to the low beam relay control circuit. This energizes the relay and applies battery positive voltage to the LEFT and RIGHT low beam fuses in the underhood fuse block. Battery positive voltage is then applied from the fuses through the headlamp supply voltage circuit to the headlamps. Ground is applied at all times to the left headlamp from G101 and to the right headlamp from G100.

Headlamps Inoperative - Low Beams
Step
Action
Yes
No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference: Master Electrical Component Listin Wiring Systems.
1
Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
Turn ON the headlamps.
Ensure that the headlamp dimmer switch is in the LOW position.
Do both low beam headlamps illuminate?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3
3
Is only one low beam headlamp inoperative?
Go to Step 12
Go to Step 4
4
Disconnect the body control module (BCM) connector C1.
Connect a jumper between the headlamp low beam relay control circuit and ground.
Do the low beam headlamps illuminate?
Go to Step 5
Go to Step 7
5
Reconnect the BCM connector C1.
Disconnect the multifunction switch.
Install a jumper between the headlamp switch headlamps ON signal circuit and ground.
Do the low beam headlamps illuminate?
Go to Step 9
Go to Step 6
6
Test for a poor connection , open or short to battery voltage, in the headlamp switch headlamps ON signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 18
Go to Step 13
7
Remove the low beam headlamp relay.
Install a fused jumper between the battery positive voltage supply circuit and the switched low beam voltage supply circuit.
Do the low beam headlamps illuminate?
Go to Step 8
Go to Step 11
8
Test for a poor connection, open or a short to battery positive voltage in the low beam relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 19
Go to Step 10
9
Inspect for a poor connection at the harness connector of the headlamp dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 19
Go to Step 14
10
Inspect for a poor connection at the low beam relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 19
Go to Step 15
11
Inspect for a poor connection at the harness connector of the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 19
Go to Step 17
12
Inspect the inoperative low beam headlamp voltage supply and ground circuit for a high resistance, short to ground, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 19
Go to Step 16
13
Test for a short to ground or a short to battery positive voltage in the exterior lamps OFF input circuit. Refer to Circuit Testingand Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 19
Go to Step 18
14
Replace the multifunction turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.
Did you complete the replacement?
Go to Step 19
--
15
Replace the low beam relay. Refer to Relay Replacement in Wiring Systems.
Did you complete the replacement?
Go to Step 19
--
16
Replace the inoperative low beam headlamp. Refer to Headlamp Assembly or Headlamp Bulb Replacement .
Did you complete the replacement?
Go to Step 19
--
17
Replace the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Did you complete the replacement?
Go to Step 19
--
18
Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?
Go to Step 19
--
19
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3

Your best bet , take your vehicle to a qualified repair shop . Before you want to replace the BCM . . Professional tech would check for DTC'S - diagnostic trouble code's in the BCM before replacing part's that are not needed .

No signal at signal wire on relay ???? Which circuit wire mite that be ? Hooking up a factory or professional scan tool to view input data from the switch would also be a good step .

Headlamps
The headlamps may be turned ON 2 different ways. First, when the driver places the headlamp switch in the HEADLAMP position, for normal operation. Second, with the headlamp switch placed in the AUTO position, for automatic lamp control (ALC). During ALC, the headlamps will be OFF in daylight conditions, or low beam operation in low light conditions. Battery positive voltage is supplied to the low beam relay and the high beam relay in the underhood fuse block. When low beam headlamps are requested, the body control module (BCM) supplies ground to the coil side of the low beam relay. This activates the relay and the relay supplies voltage to the left hand low beam headlamp through the LH LOW BEAM fuse and to the right hand low beam headlamp through the RH LOW BEAM fuse. Ground for the left hand low beam headlamp is provided at G101. Ground for the right hand low beam headlamp is provided at G102. When high beam headlamps are requested, the body control module (BCM) supplies ground to the coil side of the high beam relay. This activates the relay and the relay supplies voltage to the left hand high beam headlamp through the LH HIGH BEAM fuse and to the right hand high beam headlamp through the RH HIGH BEAM fuse. Ground for the left hand high beam headlamp is provided at G101. Ground for the right hand high beam headlamp is provided at G102.

Headlamps Inoperative - Low Beams
Step
Action
Yes
No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference: Master Electrical Component List
1
Did you perform the Diagnostic System Check - Vehicle?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Vehicle
2
Place the headlamp switch in the HEADLAMP position.
Place the headlamp dimmer switch in the LOW position.
Do the low beam headlamps illuminate?
YES - Go to Testing for Intermittent Conditions and Poor Connections
NO - Go to Step 3
3
Disconnect the turn/headlamp switch connector C2.
Connect a 15-amp fused jumper between the headlamp low beam signal circuit and a good ground.
Do the low beam headlamps illuminate?
YES - Go to Step 4
NO - Go to Step 5
4
Inspect for poor connections at the harness connector of the turn/headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
YES - Go to Step 7
NO - Go to Step 6
5
Repair an open or high resistance in the headlamp low beam signal circuit. Refer to Circuit Testing and Wiring Repairs .
YES - Did you complete the repair?
NO - Go to Step 7
--
6
Replace the turn/headlamp switch. Refer to Turn Signal Multifunction Switch Replacement .
YES - Did you complete the replacement?
NO - Go to Step 7
--
7
Operate the system in order to verify the repair.
Did you correct the condition?
YES - System OK
No - Go to Step 2

It's more then likely the dimmer switch .

DTC B2575
Circuit Description
The body control module (BCM) turns on the LOW BEAM relay when the ambient light sensor senses a dark condition or the low beam headlamps are requested ON. Battery positive voltage is supplied to the LOW BEAM relay at all times. The BCM grounds the LOW BEAM relay control circuit in order to activate the relay.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2575 Headlamp Control Circuit

B2575.01
Will set if there is a short to voltage in the low beam relay control circuit.
B2575.06
Will set if there is an open or short to ground in the low beam relay control circuit.

Headlamps
The headlamps are operated when the driver places the headlamp switch in the HEADLAMP position. The LT HDLP and RT HDLP fuse in the IP fuse block, supply battery positive voltage to both the left and right headlamps. The low beam and high beam circuits continue to the headlamp switch. Depending on the position of the dimmer switch, either the low or high beam circuit will now have a path to ground. Ground is provided at G204. The low beam and high beam circuits also provide the body control module (BCM) with both low and high beam inputs. The headlamp switch includes the dimmer and the flash-to-pass switch.
If the headlight switch is left in the HEADLAMP position, the headlights will remain on until turned off or the battery runs dead.

The ground under the battery has nothing to do with the headlamps . G-204
G204
On the steering column support bracket

Just the low beams not working ??????
Headlamps Inoperative - Low Beams
Step
Action
Yes
No
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics
1
Did you perform the Lighting System Diagnostic System Check?
YES - Go to Step 2
NO - Go to Diagnostic System Check - Lighting Systems
2
Place the headlamp switch in the HEADLAMP position.
Place the headlamp dimmer switch in the LOW position.
Do the low beam headlamps illuminate?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Inspect for poor connections at the harness connector of the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
YES - Go to Step 5
NO - Go to Step 4
4
Replace the headlamp switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column.
YES - Did you complete the replacement?
NO - Go to Step 5
--
5
Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3

Basic Electricity for Service Techs Ohm law Current Flow Opens Shorts
Electric Testing Techniques You Need to Know

Learn how to test the electrical circuit's properly . Using a DVOM - digital volt ohm meter . An get yourself good factory service repair manual ,don't guess an think you know how to fix it.

Headlamp Low or High Beams Always On

1

Was the Lighting System Diagnostic System check performed?
Go to Step 2
Go to Diagnostic System Check - Lighting Systems

2

1. Turn the ignition switch to the OFF position.
2. Turn the headlamp switch to the OFF position.

Are any of the headlamps on?
Go to Step 3
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

Disconnect the headlamp switch.
Are the headlamps on?
Go to Step 4
Go to Step 8

4

Disconnect the multifunction turn signal switch.
Are the headlamps on?
Go to Step 6
Go to Step 5

5

Test for a short to battery positive voltage in the headlamp switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES Go to Step 10
NO Go to Step 7

6

Test for a short to battery positive voltage in the headlamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
YES Go to Step 10
NO Go to Step 9

7

Replace the multifunction turn signal switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.
Did you complete the replacement?
YES Go to Step 10

8

Replace the headlamp switch. Refer to Headlamp Switch Replacement .
Did you complete the replacement?
Go to Step 10

9

Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
Did you complete the replacement?
Go to Step 10
--

10

Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2

Did you check the high/ low beam headlamp relay ? Stuck contacts in side relay .Plus headlamp relay an DRL relay .All are located in the underhood relay center .
The headlamps are controlled by the body control module (PZM). The battery positive voltage (B+) is applied at all times through the HDLPS fuse at the switch side of the headlamp relay via CKT 340 (ORN).
Battery positive voltage (B+) is also applied at all times through the RADIO/PHONE fuse to the coil side of the high/low beam headlight relay via CKT 40 (ORN/BLK). Both relays are controlled by the PZM at separate output cavities.

When the headlamp switch is in the HEAD position, the instrument cluster headlamp switch input is grounded through CKT 10 (YEL) and the headlamp switch. The instrument cluster sends a request through the Class 2 serial data line to the BCM in order to active the low beam headlamps. The BCM supplies positive battery voltage (B +) to the coil side of the headlamp relay via CKT 352 (WHT). The coil receives ground through the headlamp switch via CKT 10 (YEL). The coil of the headlamp relay is then energized, closing the switch contacts. Battery positive voltage (B +) is then applied through the high/low beam headlamp relay via CKT 1346 (LT BLU) and the L HDLP LO fuse and R HDLP LO fuse via CKT 12 (TAN) to the left and the right low beam headlamps respectively.
This may sound pretty complex .
1
Was the Headlights System Check performed?
--
YES - Go to Step 2
NO - Go to Headlight System Check
2
Are the park lamps also on?
--
YES - Go to Step 3
NO - Go to Step 13
3
Connect a Scan Tool to the data link connector (DLC).
Inspect the IPC headlamp switch input.
Does the headlamp switch operate properly?
--
YES - Go to Step 4
NO - Go to Step 10
4
Disconnect the instrument cluster (IPC) connector C3.
Do the headlamps and park lamps turn off?
--
YES - Go to Step 5
NO - Go to Step 6
5
Replace the instrument cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
Is the repair complete?
--
Go to Headlight System Check
Is the repair complete?

6
Disconnect the body control module (PZM) connector C2.
Do the headlamps and park lamps turn off?
--
Go to Step 7
Go to Step 8
7
Replace the body control module (PZM). Refer to Body Control Module Replacement in Body Control System.
Is the repair complete?
--
Go to Headlight System Check
--

Your best bet is to take it to the dealer .

Park lamp fuse 20amp located in the under hood fuse box .DRL control module
Daytime Running Lamps (DRL) Control Module
Right of the steering column, behind the IP
Park, Sidemarker, Tail and License Lamps
Voltage is applied continuously to the PARK fuse to the headlamp and the instrument panel (IP) lamp dimmer switch through CKT 1340.
When the headlamp and the (IP) lamp dimmer switch is in the PARK or HEAD position, voltage is applied to CKT 9 thus activating the following lamps:
• The park lamps
• The side marker lamps
• The tail lamps
• The license lamps
The park/turn lamps are the only lamps that do not activate yet receive a current from CKT 9. The park/turn lamps do not activate because the voltage drop across the front side marker lamps is much higher than that across the turn lamp filaments Step
Action
Normal Result(s)
Abnormal Result(s)*

1
Turn the headlamp/instrument panel (IP) lamp dimmer switch to the PARK position.
The following lamps light:
• The license plate lamps
• The taillight lamps
• The front side marker lamps (Domestic)
• The front parking lamps (Domestic)
The headlamp position lamps (Export)
Refer to Park Lamps Inoperative
Park Lamps Inoperative
Step
Action
Value(s)
Yes
No

1
Inspect the PARK LP fuse.
Is the fuse open?
--
YES - Go to Step 2
NO - Go to Step 3

2
Repair a short to ground in CKT 1340.
Is the repair complete?
--
Go to Exterior Lights System Check
--

3
Turn the headlamp/instrument panel (IP) lamp dimmer switch to the PARK position.
Use a test light in order to backprobe the headlamp/IP lamp dimmer switch harness connector between terminal R and ground.
Did the test lamp light?
--
Go to Step 7
Go to Step 4

4
Use a test light in order to backprobe the headlamp/IP lamp dimmer switch harness connector between terminal O and ground.
Did the test lamp light?
--
Go to Step 5
Go to Step 6

5
Replace the headlamp/IP lamp dimmer switch. Refer to Headlamp Switch Replacement .
Is the repair complete?
--
Go to Exterior Lights System Check
--

6
Repair the following conditions in CKT 1340 between the PARK LP fuse and the headlamp and the IP lamp dimmer switch harness connector terminal O:
• A faulty connection
• An open circuit
Is the repair complete?
--
Go to Exterior Lights System Check
--

7
Repair the following conditions in CKT 9 between the headlamp and the IP lamp dimmer switch harness connector terminal R and S204:
• A faulty connection
• An open circuit
Is the repair complete?
--
Go to Exterior Lights System Check

Two fuses HDLP L fuse #36 15amp & HDLP R fuse #32 15amp ,located in the under hood fuse / relay box. One is for Left - low an high beams an the other is for right side low an high beams . What's wrong , no high beams ?
Headlamps Inoperative - High Beams

1

Did you perform the Lighting System Diagnostic System Check?
Go to Step 2
Go to Diagnostic System Check - Lighting Systems

2

1. Turn the ignition to the OFF position.
2. Turn the headlamp switch to the HEAD position.
3. Place the headlamp dimmer switch in the high beam position.

Are the high beam headlamps operating properly?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
yes Go to Step 3


Is only one high beam headlamp inoperative?
yes Go to Step 7
Go to Step 4

4

Place the headlamp dimmer switch in the flash to pass position.
Do the high beam headlamps operate in the flash to pass position?
Go to Step 13 yes
Go to Step 5 no

5

Place the headlamp dimmer switch in the high beam position.
Does the high beam indicator illuminate?
Go to Step 12
Go to Step 6

6

Test for a high resistance, an open or a short to battery positive voltage in the high beam signal circuit of the headlamp dimmer switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 17
Go to Step 13

7

1. Disconnect the inoperative headlamp.
2. Using a test lamp connected to ground, probe the battery positive voltage circuit of the inoperative high beam headlamp.

Does the test lamp illuminate?
Go to Step 8
Go to Step 9

8

Connect a test lamp between the headlamp high beam signal circuit and the battery positive voltage circuit of the inoperative high beam headlamp.
Does the test lamp illuminate?
Go to Step 11
Go to Step 10

9

Test for a high resistance or an open in the battery positive voltage circuit of the inoperative headlamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 17
Go to Step 12

10

Test for a high resistance or an open in the headlamp high beam signal circuit of the inoperative high beam headlamp. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 17
Go to Step 12

11

Inspect for poor connections at the harness connector of the inoperative headlamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 17
Go to Step 14

12

Inspect for poor connections at the harness connector of the fuse block - underhood. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 17
Go to Step 15

13

Inspect for poor connections at the harness connector of the headlamp dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 17
Go to Step 16

14

Replace the inoperative headlamp. Refer to Headlamp Assembly or Headlamp Bulb and/or Cornering, Sidemarker, Park, Turn Signal Bulb Replacement .
Did you complete the repair?
Go to Step 17
--

15

Replace the fuse block - underhood. Refer to Underhood Electrical Center or Junction Block Replacement in Wiring Systems.
Did you complete the repair?
Go to Step 17
--

16

Replace the headlamp dimmer switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column.
Did you complete the repair?
Go to Step 17
--

17

Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 2

Drivers side is the easier side, if your arms are small enough, can reach in, in front of battery, take the dust cover off and replace. OR, if you have monster forearms, remove the battery, then it's cake.

Interesting question. Bulbs do burn out, but premature failure is often caused by overvoltage from the alternator. Have your dealer check the alternator for correct voltage AND waveforms. You can check it yourself with a multimeter. If the battery voltage is more than about 14.5Vdc, eg 15+, the alternator has to be replaced.

To Remove:

1. Ensure that the lighting switch is in the OFF position.
2. Disconnect negative battery cable.
3. Remove or disconnect the following:

• Front Fascia
• Headlamp mounting bolts.
• Headlamp by sliding it foward.
• Headlamp connectors.

To Install:

1. Install or connect the following.

• Headlamp connectors.
• Headlamp and mounting bolts.
• Front fascia.
• Negative battery cable.