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

  1. Disconnect the scan tool from the data link connector.
  2. Inspect for proper connection of the scan tool to the data link at terminal 4 and terminal 16.

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

Is the connection good?

--

Go to Step 3

Go to Step 5

3

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

Is the voltage within the specified value?

9.0 to 16.0 v

Go to Step 4

Go to Step 7

4

Using a DMM J 39200 ,measure the resistance from terminal 4 of the DLC to ground.

Is the resistance within the specified value?

0-5 ohms

Go to Step 6

Go to Step 8

5

Repair the connection as needed.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

Go to Step 2

6

Inspect the scan tool for a malfunction. Refer to the Scan Tool instruction manual.

Has a properly operating scan tool been obtained?

--

Go to Step 1

--

7

Repair an open in CKT 840 (ORN).

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

8

Repair open in CKT 750.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

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