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 1393 (Door System, Mirror System & Window System) >> Diagnostic Information and Procedures >> Power Door Locks Inoperative (Rear Door(s))

Power Door Locks Inoperative (Rear Door(s))

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.
Power Door Locks Inoperative (Rear Door(s))

Step Action Yes No
Schematic Reference:  Door Lock/Indicator Schematics  
1 Did you perform the Door Systems Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Door Systems 
2 Activate the door lock switches to the lock and unlock positions.
Do both rear passenger doors lock and unlock?		 Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3 Is there only one door lock actuator that is inoperative? Go to Step 6  Go to Step 4 
4 Are the rear door lock actuators inoperative for both lock and unlock? Go to Step 8  Go to Step 5 
5 Do the rear door lock actuators lock? Go to Step 15  Go to Step 10 
6
  1. Disconnect the inoperative door lock actuator.
  2. With a test lamp connected to a good ground, probe the door lock actuator lock circuit at the door lock actuator harness connector.
  3. Activate a door lock switch to lock position.
Does the test lamp illuminate?		 Go to Step 7  Go to Step 25 
7
  1. With a test lamp connected to a good ground, probe the door lock actuator unlock circuit at the door lock actuator harness connector.
  2. Activate a door lock switch to unlock position.
Does the test lamp illuminate?		 Go to Step 24  Go to Step 26 
8
  1. Remove the rear door unlock relay.
  2. Connect a test lamp to battery positive voltage.
  3. Probe the door actuator unlock control circuit cavity in the rear fuse block.
Does the test lamp illuminate?		 Go to Step 21  Go to Step 9 
9
  1. Install the rear door unlock relay.
  2. Remove the rear door lock relay.
  3. Connect a test lamp to battery positive voltage.
  4. Probe the door lock actuator lock control circuit cavity in the rear fuse block.
Does the test lamp illuminate?		 Go to Step 20  Go to Step 22 
10
  1. Remove the rear door lock relay.
  2. Connect a test lamp to a good ground.
  3. Probe the battery positive voltage circuit (high current) cavity in the fuse block.
Does the test lamp illuminate?		 Go to Step 11  Go to Step 22 
11 With the test lamp connected to a good ground, probe the lock relay control circuit cavity in the fuse block.
Does the test lamp illuminate?		 Go to Step 22  Go to Step 12 
12
  1. Connect a test lamp to battery positive voltage.
  2. Probe the lock relay control circuit cavity in the rear fuse block.
  3. Activate a door lock switch to the lock position.
Does the test lamp illuminate?		 Go to Step 13  Go to Step 23 
13 With the test lamp connected to battery positive voltage, probe the door lock actuator lock control circuit cavity in the rear fuse block.
Does the test lamp illuminate?		 Go to Step 20  Go to Step 14 
14
  1. Remove the rear door unlock relay.
  2. With the test lamp connected to battery positive voltage, probe the unlock relay ground circuit cavity in the rear fuse block.
Does the test lamp illuminate?		 Go to Step 21  Go to Step 22 
15
  1. Remove the rear door unlock relay.
  2. Connect a test lamp to a good ground.
  3. Probe the battery positive voltage circuit (high current) cavity in the fuse block.
Does the test lamp illuminate?		 Go to Step 16  Go to Step 22 
16 With the test lamp connected to a good ground, probe the unlock relay control circuit cavity in the fuse block.
Does the test lamp illuminate?		 Go to Step 22  Go to Step 17 
17
  1. Connect a test lamp to battery positive voltage.
  2. Probe the unlock relay control circuit cavity in the rear fuse block.
  3. Activate a door lock switch to the unlock position.
Does the test lamp illuminate?		 Go to Step 18  Go to Step 23 
18 With the test lamp connected to battery positive voltage, probe the door lock actuator unlock control circuit cavity in the rear fuse block.
Does the test lamp illuminate?		 Go to Step 21  Go to Step 19 
19
  1. Remove the rear door lock relay.
  2. With the test lamp connected to battery positive voltage, probe the lock relay ground circuit cavity in the rear fuse block.
Does the test lamp illuminate?		 Go to Step 20  Go to Step 22 
20 Inspect for poor connections at the rear door lock 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 32  Go to Step 27 
21 Inspect for poor connections at the rear door unlock 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 32  Go to Step 28 
22 Inspect for poor connections at the rear 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 32  Go to Step 29 
23 Inspect for poor connections at the harness connector of the body control module. 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 32  Go to Step 30 
24 Inspect for poor connections at the harness connector of the door lock actuator. 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 32  Go to Step 31 
25 Repair the open the door lock actuator lock circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 32  -
26 Repair the open in the door lock actuator unlock circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 32  -
27 Replace the rear door lock relay.
Did you complete the repair?		 Go to Step 32  -
28 Replace the rear door unlock relay.
Did you complete the repair?		 Go to Step 32  -
29 Replace the rear fuse block. Refer to Rear Electrical Center or Junction Block Replacement.
Did you complete the repair?		 Go to Step 32  -
30 Replace the BCM. Refer to Body Control Module Replacement in Body Control System.
Did you complete the repair?		 Go to Step 32  -
31 Replace the appropriate rear door lock actuator. Refer to Lock Actuator Replacement - Rear Door .
Did you complete the repair?		 Go to Step 32  -
32 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 2 
scientia non olet · About LEMON Manuals