GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the DLC System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Data Link Communications

2

May the scan tool be powered up?

--

Go to Step 3

Go to Scan Tool Inoperative

3

  1. Turn the ignition switch to the RUN position.
  2. Use the scan tool in order to attempt to establish communication with the SIR module.

Can communication be established?

--

System OK.

Go to Step 4

4

  1. Turn the ignition switch to the OFF position.
  2. Inspect for proper connection of the scan tool to the DLC at terminal 5.

Inspect with known good male terminal from repair kit J-38125.

Is the connection good?

--

Go to Step 6

Go to Step 5

5

Repair the connection as needed.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

Go to Step 3

6

Using a DMM J 39200 , measure the voltage from terminal 16 to terminal 5 of the DLC.

Is the voltage within the specified value?

9.0 to 16.0 v

Go to Step 7

Go to Step 20

7

Check for proper connection of the scan tool to the data link connector at terminal 9.

Inspect with known good male terminal from repair kit J-38125.

Is the connection good?

--

Go to Step 8

Go to Step 5

8

  1. Turn the ignition switch to the RUN position.
  2. Using a DMM J 39200 , measure the voltage on the DLC from terminal 9 to terminal 4.

Is the voltage within the specified value?

0.2 to 2.0 V

Go to Step 13

Go to Step 9

9

Is the voltage above the specified value?

2.0 V

Go to Step 10

Go to Step 11

10

Repair the short to battery in the UART 800 circuit.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

11

  1. Turn the ignition switch to the OFF position.
  2. Using a DMM J 39200 , measure the resistance from terminal 9 of the DLC to ground.

Is the resistance within the specified value?

OL (Infinite)

Go to Step 13

Go to Step 12

12

Repair the short to ground in the UART 800 circuit.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

13

  1. Disconnect the SIR module.
  2. Using a DMM J 39200 , measure the resistance between the SIR module cavity 5 and the DLC cavity 9.

Is the resistance within the specified value?

0 to 5.0 ohms

Go to Step 15

Go to Step 14

14

Repair the open in circuit 800 between the SIR module and the DLC.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

15

Using a DMM J 39200 , measure the resistance between the ground terminal between cavity 6 of the SIR module and ground.

Is the resistance within the specified value?

0 to 5.0 ohms

Go to Step 17

Go to Step 16

16

Repair the open in circuit 1751 between the SIR module cavity 6 and G300.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

17

Ensure the ignition is in the RUN position.

Using a DMM J 39200 , measure the voltage between the ignition terminal cavity 10 at the SIR module and ground.

Is the voltage within the specified value?

9.0 to 16.0 v

Go to Step 19

Go to Step 18

18

Repair the open in the ignition circuit to the SIR module cavity 10.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

19

Replace the SIR module.

Refer to the appropriate on-vehicle service procedures for the SIR module replacement in order to ensure a complete repair.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

20

Locate and repair the open in CKT 840 (ORN) and CKT 550 (BLK) to Splice S117.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--