GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Bonneville 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Scan Tool Does Not Communicate with Class 2 Data Line

Step

Action

Value(s)

Yes

No

1

Was the Data Link Connector System Check performed?

--

Go to Step  2

Go to Data Link Communications System Check

2
  1. Connect the scan tool to another vehicle of the same model year in order to ensure proper operation of the scan tool.
  2. Turn the ignition switch to RUN.
  3. Attempt to establish communication with the vehicle.

Does the scan tool communicate with the vehicle?

--

Go to Step  4

Go to Step  3

3

The scan tool may be malfunctioning. Refer to the scan tool instruction manual. Ensure that the scan tool is functioning.

Does the scan tool operate properly?

--

Go to Data Link Communications System Check

--

4
  1. Turn the ignition switch OFF.
  2. Connect the scan tool to the original vehicle.
  3. Verify that the scan tool connections are clean and tight.

Is the terminal contact between the DLC and the scan tool OK?

--

Go to Step  6

Go to Step  5

5

Repair the terminal contact at the DLC.

Is the repair complete?

--

Go to Data Link Communications System Check

--

6

Turn the ignition switch to RUN with the engine OFF.

Does the scan tool turn ON?

--

Go to Step  12

Go to Step  7

7

Using a DMM, measure the voltage between DLC terminal 16 and the chassis ground.

Is the voltage within the specified range?

10-15 V

Go to Step  9

Go to Step  8

8

Repair the open or the short to ground in CKT 40 (ORN).

Is the repair complete?

--

Go to Data Link Communications System Check

--

9

Measure voltage from DLC terminal 16 to terminal 5.

Is the voltage within the specified range?

10-15 V

Go to Step  11

Go to Step  10

10

Repair the open in CKT 451 (BLK/WHT).

Is the repair complete?

--

Go to Data Link Communications System Check

--

11

Repair the open in CKT 1250 (BLK).

Is the repair complete?

--

Go to Data Link Communications System Check

--

12

Measure the voltage from DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step  15

Go to Step  13

13

Using a DMM, measure the resistance from DLC terminal 2 to ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step  20

Go to Step  14

14

Repair the open in CKT 1807 (PPL) between DLC terminal 2 and S278.

Is the repair complete?

--

Go to Data Link Communications System Check

--

15
  1. Disconnect the PCM.
  2. Measure the voltage from DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step  17

Go to Step  16

16

Replace the PCM.

Is the repair complete?

--

Go to Data Link Communications System Check

--

17
  1. Disconnect the RFA.
  2. Measure the voltage from DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step  19

Go to Step  18

18

Replace the RFA.

Is the repair complete?

--

Go to Data Link Communications System Check

--

19

Repair the short to battery positive voltage (B+) in CKT 1807 (PPL).

Is the repair complete?

--

Go to Data Link Communications System Check

--

20
  1. Disconnect the PCM.
  2. Measure the resistance from DLC terminal 2 to ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step  21

Go to Step  22

21

Replace the PCM.

Is the repair complete?

--

Go to Data Link Communications System Check

--

22
  1. Disconnect the RFA.
  2. Measure the resistance from DLC terminal 2 to ground.

Is the resistance within the specified range?

0-5 ohms

Go to Step  23

Go to Step  24

23

Replace the RFA.

Is the repair complete?

--

Go to Data Link Communications System Check

--

24

Repair the short to ground in CKT 1807 (PPL).

Is the repair complete?

--

Go to Data Link Communications System Check

--