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

Step

Action

Value(s)

Yes

No

1

Did you perform the Data Link Communications Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Data Link Communications

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?

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Go to Step 4

Go to Step 3

3

The scan tool may be malfunctioning. Refer to the scan tool instruction manual in order to ensure that the scan tool is functioning.

Does the scan tool operate properly?

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Go to Step  33

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4
  1. Connect the scan tool to the original vehicle.
  2. 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 Step  33

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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

Measure the voltage between DLC terminal 16 and 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 short to ground in CKT 1140 (ORN).

Is the repair complete?

--

Go to Step  33

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9

Measure the voltage from the 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 351 (BLK/WHT).

Is the repair complete?

--

Go to Step  33

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11

Repair the open in CKT 350 (BLK).

Is the repair complete?

--

Go to Step  33

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12

Measure the voltage from the DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 15

Go to Step 13

13

Measure the resistance from the DLC terminal 2 to ground.

Is the resistance within the specified value?

0-5 ohms

Go to Step 24

Go to Step 14

14

Repair the open in CKT 1807 (PPL) between DLC terminal 2 and C200 terminal A.

Is the repair complete?

--

Go to Step  33

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15
  1. Disconnect C206.
  2. Measure the voltage from the DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 17

Go to Step 16

16

Repair the short to battery positive voltage (B+) in CKT 1807 (PPL) between C206 terminal B5 and B6.

Is the repair complete?

--

Go to Step  33

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17
  1. Disconnect C310.
  2. Measure the voltage from the DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 19

Go to Step 18

18

Repair the short to battery positive voltage (B+) in CKT 1807 (PPL) between C206 terminal B5 and C310 terminal A3.

Is the voltage within the specified range?

10-15 V

Go to Step  33

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19
  1. Reconnect C310.
  2. Disconnect C4 of the IP junction block.
  3. Measure the voltage from the DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 21

Go to Step 20

20

Repair the short to battery positive voltage (B+) in CKT 1807 (PPL) between the IP junction block connector C4 terminal F1 and C310 terminal A3.

Is the repair complete?

--

Go to Step  33

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21
  1. Reconnect C206.
  2. Measure the voltage from the DLC terminal 2 to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 22

Go to Step 23

22

Repair the short to battery positive voltage (B+) in CKT 1807 (PPL) between C206 terminal B6 and the IP junction block connector C1 terminal D12. If OK, replace the IP junction block.

Is the repair complete?

--

Go to Step  33

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23

Repair the short to battery positive voltage (B+) in CKT 1807 (PPL) between IP junction block connector C4 terminal D1 and E1.

Is the repair complete?

--

Go to Step  33

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24
  1. Disconnect C206.
  2. Measure the resistance from the DLC terminal 2 to ground.

Is the resistance within the specified value?

0-5 ohms

Go to Step 26

Go to Step 25

25

Repair the short to ground in CKT 1807 (PPL) between C206 terminal B5 and B6.

Is the repair complete?

--

Go to Step 33

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26
  1. Disconnect C310.
  2. Measure the resistance from the DLC terminal 2 to ground.

Is the resistance within the specified value?

0-5 ohms

Go to Step 28

Go to Step 27

27

Repair the short to ground in CKT 1807 (PPL) between C206 terminal B5 and C310 terminal A3.

Is the repair complete?

--

Go to Step  33

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28
  1. Reconnect C310.
  2. Disconnect C4 of the IP junction block.
  3. Measure the resistance from the DLC terminal 2 to ground.

Is the resistance within the specified value?

0-5 ohms

Go to Step 30

Go to Step 29

29

Repair the short to ground in CKT 1807 (PPL) between IP junction block connector C4 terminal F1 and C310 terminal A3.

Is the repair complete?

--

Go to Step  33

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30
  1. Reconnect C206.
  2. Measure the resistance from the DLC terminal 2 to ground.

Is the resistance within the specified value?

0-5 ohms

Go to Step 31

Go to Step 32

31

Repair the short to ground in CKT 1807 (PPL) between C206 terminal B6 and IP junction block connector C1 terminal D12. If OK, replace the IP block.

Is the repair complete?

--

Go to Step  33

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32

Repair the short to ground in CKT 1807 (PPL) between IP junction block connector C4 terminal D1.

Is the repair complete?

--

Go to Step  33

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33
  1. Turn the ignition switch to OFF.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn the ignition switch to ON.
  4. Clear any DTCs.

Are all of the DTCs cleared?

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Go to Diagnostic System Check - Data Link Communications

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