GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Data Link Communications Systems Check?

--

Go to Step 2

Go to Data Link Communications System Check

2

  1. Inspect the data link connector (DLC). Repair any damaged terminals if required.
  2. Verify that the Scan Tool is firmly connected to the DLC.
  3. Turn the ignition switch to the RUN position.
  4. Attempt scan tool communications with the transmission control module (TCM).

Can communications be established?

--

System OK

Go to Step 3

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the TCM.
  3. Use a J 39200 DMM in order to measure the resistance on the DLC from terminal 6 to terminal 5.

Is the resistance greater than the specified value?

10M ohms

Go to Step 5

Go to Step 4

4

Locate and repair the short to ground in CKT 448 (WHT/BLK).

Did you complete the repair?

--

System OK

--

5

Use a J 39200 DMM in order to measure the resistance on the DLC from terminal 9 to terminal 5.

Is the resistance greater than the specified value?

10M ohms

Go to Step 7

Go to Step 6

6

Locate and repair the short to ground in CKT 800 (TAN).

Did you complete the repair?

--

System OK

--

7

Use a J 39200 DMM in order to measure the resistance from the DLC terminal 6 to terminal 9.

Is the resistance greater than the specified value?

10M ohms

Go to Step 9

Go to Step 8

8

Locate and repair the short between CKT 448 (WHT/BLK) and CKT 800 (TAN).

Did you complete the repair?

--

System OK

--

9

Use a J 39200 DMM in order to measure the voltage from the DLC terminal 6 to terminal 5.

Is the voltage greater than the specified value?

1.0 V

Go to Step 10

Go to Step 11

10

Locate and repair the short to B+ in CKT 448 (BLK/WHT).

Did you complete the repair?

--

System OK

--

11

Use a J 39200 DMM in order to measure the voltage from the DLC terminal 9 to terminal 5.

Is the voltage greater than the specified value?

1.0 V

Go to Step 12

Go to Step 13

12

Locate and repair the short to B+ in CKT 800 (TAN).

Did you complete the repair?

--

System OK

--

13

Use a J 39200 DMM in order to measure the resistance from the DLC terminal 6 to the TCM connector C2, cavity A8.

Is the resistance greater than the specified value?

1.0 ohms

Go to Step 14

Go to Step 15

14

Locate and repair the open in CKT 448 (BLK/WHT).

Did you complete the repair?

--

System OK

--

15

Use a J 39200 DMM in order to measure the resistance from the DLC terminal 9 to the TCM connector C2, cavity B10.

Is the resistance greater than the specified value?

1.0 ohms

Go to Step 16

Go to Step 17

16

Locate and repair the open in CKT 800 (TAN).

Did you complete the repair?

--

System OK

--

17

  1. Connect the TCM.
  2. Turn the ignition switch to the RUN position.
  3. Install the scan tool.
  4. Attempt to establish communications with the TCM.

Can communications be established?

--

System OK

Go to Step 1