LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1657 (Lighting Systems) >> Diagnostic Information and Procedures >> Headlamps Inoperative - Low Beams

Headlamps Inoperative - Low Beams

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Headlamps Inoperative - Low Beams

Step Action Yes No
Schematic Reference:  Headlights/Daytime Running Lights (DRL) Schematics  
1 Did you perform the Lighting Systems Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Lighting Systems 
2 Verify that the low beam headlamps are inoperative.
Do the low beam headlamps operate normally?		 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 4  Go to Step 5 
4
  1. Inspect the inoperative bulb for an open filament and connector for poor terminal contact and replace/repair as necessary. Refer to Headlamp Bulb Replacement  or WIRING REPAIRS in Wiring Systems
  2. If no problem is found, repair the open, high resistance or short to ground in the low beam headlamp supply voltage circuit or ground circuit to the inoperative lamp. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Did you complete the repair?		 Go to Step 19  -
5 Does the wiper activated headlamp (WAH) function of the wiper system operate normally? Go to Step 8  Go to Step 6 
6
  1. Block the wheels.
  2. Place the ignition switch in the RUN position with the engine OFF.
  3. Place the gearshift lever in DRIVE.
  4. Place the wiper switch in the LO speed position.
  5. Use the scan tool to monitor the Front Wipers Active input to the BCM.
Does the scan tool display Yes after approximately 3 cycles of the wiper blades?		 Go to Step 14  Go to Step 7 
7 Test the windshield wiper switch signal 2 circuit for an open, high resistance, or short to voltage. Refer toCIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Did you find and correct a condition?		 Go to Step 19  Go to Step 13 
8 Test the headlamp switch signal and ground circuits for an open or high resistance. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Did you find and correct a condition?		 Go to Step 19  Go to Step 9 
9
  1. Place the headlamp switch in the HEAD position.
  2. Connect a fused jumper from ground to the headlamp switch signal terminal of the headlamp switch connector.
Do the low beam headlamps illuminate?		 Go to Step 12  Go to Step 10 
10 Connect a fused jumper from ground to the headlamp driver module control circuit terminal at the headlamp driver module (HDM) in the underhood fuse block.
Do the low beam headlamps illuminate?		 Go to Step 14  Go to Step 11 
11 Test the headlamp driver module ground circuit for an open or high resistance. Refer toCIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Did you find and correct a condition?		 Go to Step 19  Go to Step 17 
12 Inspect for poor connections at the harness connector of the headlamp switch. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Did you find and correct the condition?		 Go to Step 19  Go to Step 18 
13 Inspect for poor connections at the harness connector of the wiper motor cover. Refer to CIRCUIT TESTING and WIRING REPAIRS in Wiring Systems.
Did you find and correct the condition?		 Go to Step 19  Go to Step 15 
14 Inspect for poor connections at the harness connector of the Body Control Module (BCM). 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 
15 Replace the wiper motor cover. Refer to WIPER MOTOR COVER REPLACEMENT in Wipers/Washers Systems.
Did you complete the repair?		 Go to Step 19  -
16
IMPORTANT: Perform the setup procedure for the BCM.
Replace the body control module (BCM). Refer to BODY CONTROL MODULE REPLACEMENT in Body Control System.Did you complete the replacement?		 Go to Step 19  -
17 Replace the headlamp driver module (HDM). Refer to Headlamp Driver Module (HDM) Relay Replacement .
Did you complete the repair?		 Go to Step 19  -
18 Replace the headlamp switch. Refer to Headlamp Switch Replacement .
Did you complete the repair?		 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 
scientia non olet · About LEMON Manuals