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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 Headlamps Inoperative - Low Beams

Headlamps Inoperative - Low Beams Standard

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

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 switch to the ON position.
  2. Turn the headlamp switch to the HEAD position.
  3. Determine if the low beam headlamps are inoperative.

Are the low beam headlamps operating properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Are both low beam headlamps inoperative?

Go to Step 4

Go to Step 10

4
  1. Disconnect the low beam relay K131 connector.
  2. Probe the switch side feed circuit (A814) of the low beam relay K130 connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 18

5

Connect a fused jumper between the switch side feed (A814) and the low beam supply voltage circuit (B50) of the low beam relay K131 connector.

Do the low beam headlamps turn ON?

Go to Step 6

Go to Step 17

6
  1. Turn the headlamp switch to the HEAD position.
  2. Probe the control circuit (XA810) of the low beam relay K130 connector with a test lamp that is connected B+.

Does the test lamp illuminate?

Go to Step 23

Go to Step 7

7
  1. Disconnect the BCM connector C2.
  2. Turn the headlamp switch to the HEAD position.
  3. Probe the low beam On/Off circuit (B899) of the BCM connector C2 with a test lamp that is connected B+.

Does the test lamp illuminate?

Go to Step 25

Go to Step 8

8

Test for an open or high resistance in the low beam On/Off circuit (B899, B60) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 9

9

Test for an open or high resistance in the headlamp switch ground circuit (F18) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 24

10

Is the LH low beam headlamp inoperative?

Go to Step 11

Go to Step 14

11

Check the LO BEAM LH Fuse for an open.

Is the LO BEAM LH Fuse open?

Go to Step 20

Go to Step 12

12

Test for an open or high resistance in the LH low beam supply voltage circuit (B4 ,B11, B1) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 13

13

Test for an open or high resistance in the LH low beam ground circuit (F840) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 21

14

Check the LO BEAM RH Fuse for an open.

Is the LO BEAM RH Fuse open?

Go to Step 19

Go to Step 15

15

Test for an open or high resistance in the RH low beam supply voltage circuit (B5,B45,B3,B22) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 16

16

Test for an open or high resistance in the RH low beam ground circuit (F11) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 26

Go to Step 22

17

Repair an open or high resistance in the low beam supply voltage circuit (B50) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 26

--

18

Repair an open or high resistance in the switch side feed circuit (A814) of the low beam relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 26

--

19

Repair a short to ground in the RH low beam supply voltage circuit (B45,B22,B3,B800,B905) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 26

--

20

Repair a short to ground in the LH low beam supply voltage circuit (B1,B11,B55) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 26

--

21

Replace the LH headlamp. Refer to Headlamp Capsule Replacement .

Does the LH low beam operate properly?

Go to Step 26

--

22

Replace the RH headlamp. Refer to Headlamp Capsule Replacement .

Does the RH low beam operate properly?

Go to Step 26

--

23

Replace the low beam relay K131.

Is the replacement complete?

Go to Step 26

--

24

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the replacement complete?

Go to Step 26

--

25

Test for a poor connection at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Is the repair complete?

Go to Step 26

--

26
  1. Connect all of the connectors and components that were disconnected.
  2. Verify that the low beam headlamps operate properly.

Do the low beam headlamps operate properly?

System OK

Go to Step 2

Headlamps Inoperative - Low Beams High Intensity Discharge (HID)

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

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 switch to the ON position.
  2. Turn the headlamp switch to the HEAD position.
  3. Determine if the low beam headlamps are inoperative.

Are the low beam headlamps operating properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Are both low beam headlamps inoperative?

Go to Step 4

Go to Step 10

4
  1. Disconnect the low beam relay K131 connector.
  2. Probe the switch side feed circuit (A814) of the low beam relay K130 connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 22

5

Connect a fused jumper between the switch side feed (A814) and the low beam supply voltage circuit (B50) of the low beam relay K131 connector.

Do the low beam headlamps turn ON?

Go to Step 6

Go to Step 21

6
  1. Turn the headlamp switch to the HEAD position.
  2. Probe the control circuit (XA810) of the low beam relay K130 connector with a test lamp that is connected B+.

Does the test lamp illuminate?

Go to Step 25

Go to Step 7

7
  1. Disconnect the BCM connector C2.
  2. Turn the headlamp switch to the HEAD position.
  3. Probe the low beam On/Off circuit (B899) of the BCM connector C2 with a test lamp that is connected B+.

Does the test lamp illuminate?

Go to Step 27

Go to Step 8

8

Test for an open or high resistance in the low beam On/Off circuit (B899, B60) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 9

9

Test for an open or high resistance in the headlamp switch ground circuit (F18) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 26

10

Is the LH low beam inoperative?

Go to Step 11

Go to Step 16

11

Check the LO BEAM LH Fuse for an open.

Is the LO BEAM LH Fuse open?

Go to Step 24

Go to Step 12

12

Test for an open or high resistance in the LH low beam supply voltage circuit (B4, B11) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 13

13

Test for an open or high resistance in the LH low beam ground circuit (F14) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 14

14

Install a known good ballast. Refer to High Intensity Discharge Headlamp Ballast Replacement .

Does the lamp operate properly?

Go to Step 28

Go to Step 15

15

Replace the arc tube assembly for the left headlamp. Refer to HID Headlamp Starter/Arc Tube Replacement (Delphi) .

Is the repair complete?

Go to Step 28

--

16

Check the LO BEAM RH Fuse for an open.

Is the LO BEAM RH Fuse open?

Go to Step 23

Go to Step 17

17

Test for an open or high resistance in the RH low beam supply voltage circuit (B5, B45, B30) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 18

18

Test for an open or high resistance in the RH low beam ground circuit (F13) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 19

19

Install a known good ballast. Refer to High Intensity Discharge Headlamp Ballast Replacement .

Does the lamp operate properly?

Go to Step 28

Go to Step 20

20

Replace the arc tube assembly for the left headlamp. Refer to HID Headlamp Starter/Arc Tube Replacement (Delphi) .

Is the repair complete?

Go to Step 28

--

21

Repair an open or high resistance in the low beam supply voltage circuit (B50) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 28

--

22

Repair an open or high resistance in the switch side feed circuit (A814) of the low beam relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 28

--

23

Repair a short to ground in the RH low beam supply voltage circuit (B45,B22,B30,B800,B905). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 28

--

24

Repair a short to ground in the LH low beam supply voltage circuit (B11, B55) . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 28

--

25

Replace the low beam relay K131.

Is the replacement complete?

Go to Step 28

--

26

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the replacement complete?

Go to Step 28

--

27

Test for a poor connection at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Is the repair complete?

Go to Step 28

--

28
  1. Connect all of the connectors and components that were disconnected.
  2. Verify that the low beam headlamps operate properly.

Do the low beam headlamps operate properly?

System OK

Go to Step 2