GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1999 🢒 Regal (China) (CNG) 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Scan Tool Does Not Communicate with Class 2 Data Line

Step

Action

Value(s)

Yes

No

1

Was the Data Link Connector (DLC) Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Data Link Communications

2

Is the scan tool properly configured to interface with this vehicle?

--

Go to Step 3

Go to Step 28

3
  1. Connect scan tool on a known good vehicle.
  2. Perform the DLC Diagnostic System Check on known good vehicle.

Does the scan tool communicate with the good known vehicle?

--

Go to Step 4

Go to Step 28

4
  1. Turn the ignition switch off.
  2. Disconnect the Splice Pack SP205 electrical connector.
  3. Using a DMM, measure the resistance between the DLC terminal 2 and ground.

Is the resistance within the specified range?

∞

Go to Step 5

Go to Step 29

5
  1. Turn the ignition switch on.
  2. Using a DMM, measure the voltage between the DLC terminal 2 and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 6

Go to Step 30

6

Using a DMM, measure the resistance between the DLC terminal 2 and the SP205 harness connector terminal A.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 7

Go to Step 31

7
  1. Turn the ignition switch off.
  2. Disconnect the battery negative terminal.
  3. Reconnect the Splice Pack SP205.

Using a DMM, measure the resistance by backprobing between the SP205 terminal A and each of the SP205 terminals B, E, F, G, L, and M (one pair of terminals at a time).

Is the resistance within the specified range?

Less than 2ohms

Go to Step 8

Go to Step 32

8
  1. Disconnect the Splice Pack SP205 again.
  2. Disconnect the Powertrain Control Module (PCM) connector C1.
  3. Using a DMM, measure the resistance between the SP205 harness connector terminal B and ground.

Is the resistance within the specified range?

∞

Go to Step 9

Go to Step 33

9
  1. Reconnect the battery negative terminal.
  2. Turn the ignition switch on.
  3. Using a DMM, measure the voltage between the SP205 harness connector terminal B and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 10

Go to Step 34

10

Using a DMM, measure the resistance between the SP205 harness connector terminal B and the PCM harness connector C1 terminal 58.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 11

Go to Step 35

11
  1. Turn the ignition switch off.
  2. Disconnect the Electronic Brake Traction Control (EBTCM) connector.
  3. Using a DMM, measure the resistance between the SP205 harness connector terminal E and ground.

Is the resistance within the specified range?

∞

Go to Step 12

Go to Step 36

12
  1. Turn the ignition switch on.
  2. Using a DMM, measure the voltage between the SP205 harness connector terminal E and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 13

Go to Step 37

13

Using a DMM, measure the resistance between the SP205 harness connector terminal E and the EBTCM harness connector terminal B7.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 14

Go to Step 38

14
  1. Turn the ignition switch off.
  2. Disconnect the instrument cluster electrical connector.
  3. Using a DMM, measure the resistance between the SP205 harness connector terminal G and ground.

Is the resistance within the specified range?

∞

Go to Step 15

Go to Step 39

15
  1. Turn the ignition switch on.
  2. Using a DMM, measure the voltage between the SP205 harness connector terminal G and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 16

Go to Step 40

16

Using a DMM, measure the resistance between the SP205 harness connector terminal G and the instrument cluster harness connector terminal B2.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 17

Go to Step 41

17
  1. If vehicle is not equipped with auto climate control (RPO CJ2), skip to Step 20 .
  2. Turn the ignition switch off.
  3. Disconnect the heater-AC control electrical connector.
  4. Using a DMM, measure the resistance between the SP205 harness connector terminal L and ground.

Is the resistance within the specified range?

∞

Go to Step 18

Go to Step 42

18
  1. Turn the ignition switch on.
  2. Using a DMM, measure the voltage between the SP205 harness connector terminal L and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 19

Go to Step 43

19

Using a DMM, measure the resistance between the SP205 harness connector terminal L and the heater-AC control harness connector terminal D12.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 20

Go to Step 44

20
  1. Turn the ignition switch off.
  2. Disconnect the Body Control Module (BCM) connector C2.
  3. Using a DMM, measure the resistance between the SP205 harness connector terminal M and ground.

Is the resistance within the specified range?

∞

Go to Step 21

Go to Step 45

21
  1. Turn the ignition switch on.
  2. Using a DMM, measure the voltage between the SP205 harness connector terminal M and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 22

Go to Step 46

22

Using a DMM, measure the resistance between the SP205 harness connector terminal M and the BCM harness connector C2 terminal B5.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 49

Go to Step 47

23
  1. Turn the ignition switch off.
  2. Reconnect the PCM connector C1 (leave other modules disconnected).
  3. Reconnect Splice Pack SP 205.
  4. Turn the ignition switch on.
  5. Using scan tool, attempt to communicate with the PCM.

Does scan tool communicate with PCM?

--

Go to Step 24

Go to DTC U1016 Loss of Communications with PCM VIN K , 1) in Engine Controls

24
  1. Turn the ignition switch off.
  2. Reconnect the EBTCM connector.
  3. Turn the ignition switch on.
  4. Using scan tool, attempt to communicate with the EBTCM.

Does scan tool communicate with EBTCM?

--

Go to Step 25

Go to Scan Tool Diagnostics in Antilock Brake System

25
  1. Turn the ignition switch off.
  2. Reconnect the instrument cluster electrical connector.
  3. Turn the ignition switch on.
  4. Using scan tool, attempt to communicate with the instrument cluster.

Does scan tool communicate with the instrument cluster?

--

Go to Step 26

Go to Instrument Cluster Diagnostic System Check in Instrument Panel, Gauges and Console

26
  1. If vehicle is not equipped with auto climate control, skip to Step 27 .
  2. Turn the ignition switch off.
  3. Reconnect the heater-AC control electrical connector.
  4. Turn the ignition switch on.
  5. Using scan tool, attempt to communicate with the heater-AC control.

Does scan tool communicate with the heater-AC control?

--

Go to Step 27

Go to A Diagnostic System Check in HVAC Systems with A/C - Automatic

27
  1. Turn the ignition switch off.
  2. Reconnect the BCM connector C2.
  3. Turn the ignition switch on.
  4. Using scan tool, attempt to communicate with the BCM.

Does scan tool communicate with the BCM?

--

Go to Step 55

Go to Scan Tool Diagnostics in Body Control System

28

Refer to the scan tool manufacturer and/or scan tool user's manual for correct operation of the scan tool.

Is the action complete?

--

Go to Diagnostic System Check - Data Link Communications

--

29

Repair short to ground in circuit 1132.

Is the repair complete?

--

Go to Step 48

--

30

Repair short to B+ in circuit 1132.

Is the repair complete?

--

Go to Step 48

--

31

Repair poor connection or open in circuit 1132.

Is the repair complete?

--

Go to Step 48

--

32

Replace the Splice Pack SP205.

Is the repair complete?

--

Go to Step 48

--

33

Repair short to ground in circuit 1049.

Is the repair complete?

--

Go to Step 48

--

34

Repair short to B+ in circuit 1049.

Is the repair complete?

--

Go to Step 48

--

35

Repair poor connection or open in circuit 1049.

Is the repair complete?

--

Go to Step 48

--

36

Repair short to ground in circuit 1122.

Is the repair complete?

--

Go to Step 48

--

37

Repair short to B+ in circuit 1122.

Is the repair complete?

--

Go to Step 48

--

38

Repair poor connection or open in circuit 1122.

Is the repair complete?

--

Go to Step 48

--

39

Repair short to ground in circuit 1036.

Is the repair complete?

--

Go to Step 48

--

40

Repair short to B+ in circuit 1036.

Is the repair complete?

--

Go to Step 48

--

41

Repair poor connection or open in circuit 1036.

Is the repair complete?

--

Go to Step 48

--

42

Repair short to ground in circuit 1038.

Is the repair complete?

--

Go to Step 48

--

43

Repair short to B+ in circuit 1038.

Is the repair complete?

--

Go to Step 48

--

44

Repair poor connection or open in circuit 1038.

Is the repair complete?

--

Go to Step 48

--

45

Repair short to ground in circuit 1037.

Is the repair complete?

--

Go to Step 48

--

46

Repair short to B+ in circuit 1037.

Is the repair complete?

--

Go to Step 48

--

47

Repair open or poor connection in circuit 1037.

Is the repair complete?

--

Go to Step 48

--

48
  1. Turn the ignition switch off.
  2. Reinstall connectors/components removed.

Is the action complete?

--

Go to Diagnostic System Check - Data Link Communications

--

49
  1. Turn the ignition switch off.
  2. Disconnect the inflatable restraint sensing and diagnostic Module (SDM) harness connector.
  3. Using a DMM, measure the resistance between the SP205 harness connector terminal F and ground.

Is the resistance within the specified range?

∞

Go to Step 50

Go to Step 52

50
  1. Turn the ignition switch on.
  2. Using a DMM, measure the voltage between the SP205 harness connector terminal F and ground.

Is the voltage within the specified range?

Less than 2V

Go to Step 51

Go to Step 53

51

Using a DMM, measure the resistance between the SP205 harness connector terminal F and the SDM harness connector terminal A5.

Is the resistance within the specified range?

Less than 2ohms

Go to Step 23

Go to Step 54

52

Repair short to ground in circuit 1128.

Is the repair complete?

--

Go to Step 48

--

53

Repair short to B+ in circuit 1128.

Is the repair complete?

--

Go to Step 48

--

54

Repair poor connection or open in circuit 1128.

Is the repair complete?

--

Go to Step 48

--

55
  1. Turn the ignition switch off.
  2. Reconnect the SDM connector.
  3. Turn the ignition switch on.
  4. Using scan tool, attempt to communicate with the SDM.

Does scan tool communicate with the SDM?

--

System OK

Go to SIR Diagnostic System Check in Restraints