GM Service Manual Online
For 1990-2009 cars only

Seat Belt Tower Inoperative W/A45

Step

Action

Yes

No

Schematic Reference: Memory Seats Schematics

1

Did you perform the Diagnostic System Check - Power Seats Systems?

Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

Verify that the Seat Belt Tower Inoperative complaint is present.

Does the power seat belt tower operate as described in the system description and operation?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Belt Tower UP parameter in the Memory Seat Module data list.
  4. Operate the Belt Tower UP switch.

Does the Belt Tower UP parameter change state?

Go to Step 4

Go to Step 6

4

  1. With a scan tool, observe the Belt Tower DOWN parameter.
  2. Operate the Belt Tower DOWN switch.

Does the Belt Tower DOWN parameter change state?

Go to Step 5

Go to Step 7

5

  1. Disconnect the belt tower motor harness connector.
  2. Connect a test lamp between the belt tower motor up control circuit and the belt tower motor down control circuit of the harness connector.
  3. Operate the belt tower switch in the UP and DOWN directions.

Does the test lamp illuminate in both directions?

Go to Step 14

Go to Step 8

6

  1. Disconnect the power seat switch harness connector.
  2. Connect a 3 amp fused jumper wire from battery positive voltage (B+) to the belt tower up switch signal circuit of the harness connector.
  3. With a scan tool, observe the Belt Tower UP parameter.

Does the Belt Tower UP parameter change state?

Go to Step 13

Go to Step 10

7

  1. Disconnect the power seat switch harness connector.
  2. Connect a 3 amp fused jumper wire from battery positive voltage (B+) to the belt tower down switch signal circuit of the harness connector.
  3. With a scan tool, observe the Belt Tower DOWN parameter.

Does the Belt Tower DOWN parameter change state?

Go to Step 13

Go to Step 11

8

Test the belt tower motor up control circuit between the memory seat module and the belt tower motor for a 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 18

Go to Step 9

9

Test the belt tower motor down control circuit between the memory seat module and the belt tower motor for a 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 18

Go to Step 12

10

Test the belt tower up switch signal circuit between the power seat switch and the memory seat module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 12

11

Test the belt tower down switch signal circuit between the power seat switch and the memory seat module for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 12

12

Inspect for poor connections at the harness connector of the memory seat 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 18

Go to Step 15

13

Inspect for poor connections at the harness connector of the power seat 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 18

Go to Step 16

14

Inspect for poor connections at the harness connector of the belt tower. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 17

15

Replace the memory seat module (MSM). Refer to Memory Seat Control Module Replacement in Seats.

Did you complete the replacement?

Go to Step 18

--

16

Replace the power seat switch. Refer to Power Seat Switch Replacement in Seats.

Did you complete the replacement?

Go to Step 18

--

17

Replace the shoulder belt tower. Refer to Shoulder Belt Tower Replacement in Seats.

Did you complete the replacement?

Go to Step 18

--

18

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Seat Belt Tower Inoperative WO/A45

Step

Action

Yes

No

Schematic Reference: Power Seats Schematics

1

Did you review the power seat system operation and perform the necessary inspection?

Go to Step 2

Go to Symptoms - Seats

2

Verify that the Seat Belt Tower Inoperative complaint is present.

Does the belt tower system operate as described in the system description and operation?

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

Go to Step 3

3

  1. Probe the belt tower motor up control circuit of the power seat switch with a test lamp that is connected to a good ground.
  2. Operate the belt tower UP switch.

Does the test lamp illuminate?

Go to Step  4

Go to Step 6

4

  1. Probe the belt tower motor down control circuit of the power seat switch with a test lamp that is connected to a good ground.
  2. Operate the belt tower DOWN switch.

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

5

  1. Disconnect the belt tower motor harness connector.
  2. Connect a test lamp between the belt tower motor up control circuit and the belt tower motor down control circuit of the harness connector.
  3. Operate the belt tower switch in the UP and DOWN directions.

Does the test lamp illuminate in both directions?

Go to Step 7

Go to Step 8

6

Inspect for poor connections at the harness connector of the power seat 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 11

Go to Step 9

7

Inspect for poor connections at the harness connector of the belt tower motor. 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 11

Go to Step 10

8

Test and repair the open in the up or down control circuit of the belt tower motor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

--

9

Replace the power seat switch. Refer to Power Seat Switch Replacement in Seats.

Did you complete the replacement?

Go to Step 11

--

10

Replace the shoulder belt tower. Refer to Shoulder Belt Tower Replacement in Seats.

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2