GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 Body and Accessories 🢒 Seats 🢒 Scan Tool Does Not Communicate with Class 2 Data Line

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic 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 (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 in order to ensure that the scan tool is functioning.

Does the scan tool operate properly?

--

Go to Data Link Communications System Check

--

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 71

--

6

Turn the ignition switch to RUN.

Does the scan tool turn on?

--

Go to Step 12

Go to Step 7

7

Measure the voltage between the 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 3640 (ORN).

Is the repair complete?

--

Go to Step 71

--

9

Measure the voltage from the DLC terminal 16 to terminal 5.

Is the voltage within 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 71

--

11

Check for voltage from DLC terminal 16 to terminal 4.

Is the voltage within specified range?

10-15 V

Go to Step 13

Go to Step 12

12

Repair the open in CKT 450 (BLK).

Is the circuit repair complete?

--

Go to Step 71

--

13
  1. Disconnect the Powertrain Control Module (PCM).
  2. Attempt to establish communications with the Dash Integration Module (DIM).

Does the scan tool communicate with the vehicle?

--

Go to Step 14

Go to Step 15

14

Replace the PCM.

Is the repair complete?

--

Go to Step 71

--

15
  1. Disconnect the Electronic Brake and Traction Control Module (EBCTM).
  2. Attempt to establish communication with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 16

Go to Step 18

16

Inspect CKT 1807 (PPL) between the EBTCM terminal 10 and the PCM C1 terminal 59 for a short to ground or battery positive voltage (B+).

Was a short found?

--

Go to Step 70

Go to Step 17

17

Replace the EBTCM.

Is the repair complete?

--

Go to Step 71

--

18

Is the vehicle equipped with A45?

--

Go to Step 19

Go to Step 21

19
  1. Disconnect the Memory Seat Module (MSM).
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 20

Go to Step 21

20

Replace the MSM.

Is the repair complete?

--

Go to Step 71

--

21

Is the vehicle equipped with a cellular telephone module?

--

Go to Step 22

Go to Step 24

22
  1. Disconnect the cellular telephone module.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 23

Go to Step 24

23

Replace the cellular telephone module.

Is the repair complete?

--

Go to Step 71

--

24
  1. Disconnect the instrument cluster (IPC).
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 25

Go to Step 27

25

Inspect CKT 1807 (PPL) between the IPC C2 terminal B8 and the EBTCM terminal 26 for a short to ground or battery positive voltage (B+).

Was a short found?

--

Go to Step 70

Go to Step 26

26

Replace the IPC.

Is the repair complete?

--

Go to Step 71

 

27
  1. Disconnect the Pass-Key III Theft Deterrent Module.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 28

Go to Step 30

28

Inspect CKT 1807 (PPL) between the Pass-Key III Theft Deterrent Module terminal E and the IPC C1 terminal B8 for a short to ground or battery positive voltage (B+).

Was a short found?

--

Go to Step 70

Go to Step 29

29

Replace the Pass-Key III Theft Deterrent Module.

Is the repair complete?

--

Go to Step 71

--

30

Is the vehicle equipped with N37?

--

Go to Step 31

Go to Step 33

31
  1. Disconnect the steering column tilt/telescoping module.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 32

Go to Step 33

32

Replace the steering column tilt/telescoping module.

Is the repair complete?

--

Go to Step 71

--

33

Is the vehicle equipped with UY4?

--

Go to Step 37

Go to Step 34

34
  1. Disconnect the radio.
  2. Attempt to establish communication with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 35

Go to Step 37

35

Inspect CKT 1807 (PPL) between the radio terminal E6 and the Pass-Key II Theft Deterrent Module terminal E for a short to ground or battery positive voltage (B+).

Was a short found?

--

Go to Step 70

Go to Step 36

36

Replace the radio.

Is the repair complete?

--

Go to Step 71

--

37
  1. Disconnect the Instrument Panel Integration Module (IPM).
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 38

Go to Step 40

38

Inspect CKT 1807 (PPL) for a short to ground or a battery positive voltage (B+) between the IPM C1 terminal C7 and one of the following components:

    • Radio terminal F6 (W/O UY4).
    • Pass-Key III Theft Deterrent Module Terminal E (W/ UY4).

Was a short found?

--

Go to Step 70

Go to Step 39

39

Replace the IPM.

Is the repair complete?

--

Go to Step 71

--

40
  1. Disconnect the Left Front Door Module (LFDM).
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 41

Go to Step 42

41

Replace the LFDM.

Is the repair complete?

--

Go to Step 71

--

42
  1. Disconnect the Remote Keyless Entry Module (RKE).
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 43

Go to Step 44

43

Replace the RKE module.

Is the repair complete?

--

Go to Step 71

--

44

Is the vehicle equipped with U84?

--

Go to Step 47

Go to Step 45

45
  1. Disconnect the radio amplifier.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 46

Go to Step 56

46

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the radio amplifier C1 terminal B11 (W/U48), C3 terminal 5 (W/U49) and one of the following components:

    • RKE module terminals 3 and 4.
    • MSM C2 terminals D14 and D15.
    • LFDM C1 terminal 13.
    • PCM C1 terminal 58.

Was a short found?

--

Go to Step 70

Go to Step 55

47
  1. Disconnect the radio.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 48

Go to Step 50

48

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the radio C1 terminal F6 and the RKE module terminal 3.

Was a short found?

--

Go to Step 70

Go to Step 49

49

Replace the radio.

Is the repair complete?

--

Go to Step 71

--

50
  1. Disconnect the navigation data processor.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 51

Go to Step 53

51

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the radio C1 terminal E6 and the navigation data processor C1 terminal 2.

Was a short found?

--

Go to Step 70

Go to Step 52

52

Replace the navigation data processor.

Is the repair complete?

--

Go to Step 71

--

53
  1. Disconnect the radio amplifier.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 54

Go to Step 56

54

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the radio amplifier C1 terminal B11 (W/U48), C3 terminal 5 (W/U49) and the navigation data processor C1 terminal 3.

Was a short found?

--

Go to Step 70

Go to Step 55

55

Replace the radio amplifier.

Is the repair complete?

--

Go to Step 71

--

56

Is the vehicle equipped with F45?

--

Go to Step 57

Go to Step 60

57
  1. Disconnect the CVRSS module.
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 58

Go to Step 60

58

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the CVRSS module C1 terminal D4 and the radio amplifier.

Was a short found?

--

Go to Step 70

Go to Step 59

59

Replace the CVRSS module.

Is the repair complete?

--

Go to Step 70

--

60
  1. Disconnect the Rear Integration Module (RIM).
  2. Attempt to establish communication with the DIM.

Does the vehicle communicate with the vehicle?

--

Go to Step 61

Go to Step 63

61

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the RIM C2 terminal B3 and the CVRSS module (W/F45), or the radio amplifier (W/O F45).

Was a short found?

--

Go to Step 70

Go to Step 62

62

Replace the RIM.

Is the repair complete?

--

Go to Step 71

--

63
  1. Disconnect the inflatable restraint sensing and diagnostic module (SDM).
  2. Attempt to establish communications with the DIM.

Does the scan tool communicate with the vehicle?

--

Go to Step 64

Go to Step 66

64

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the SDM terminal 5 and the following components:

    • RIM C2 terminal B4.
    • Cellular telephone module terminal 9.

Was a short found?

--

Go to Step 70

Go to Step 65

65

Replace the SDM.

Is the repair complete?

--

Go to Step 71

--

66
  1. Reconnect the IPM.
  2. Disconnect the DIM.
  3. Attempt to establish communications with the IPM.

Does the scan tool communicate with the vehicle?

--

Go to Step 67

Go to Step 69

67

Inspect CKT 1807 (PPL) for a short to ground or battery positive voltage (B+) between the DIM C2 terminal A11 and the SDM terminal 17.

Was a short found?

--

Go to Step 70

Go to Step 68

68

Replace the DIM.

Is the repair complete?

--

Go to Step 71

--

69

Repair an open or short to ground or battery positive voltage (B+) in CKT 1807 (PPL) between the DLC terminal 2 and one of the following components:

    • IPM C1 terminal C8.
    • DIM C2 terminal A12.

Is the repair complete?

--

Go to Step 71

--

70

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

Is the repair complete?

--

Go to Step 71

--

71
  1. Reconnect or reinstall any connectors or components that were disconnected or removed.
  2. Clear all of the DTC's.

Are all of the DTC's cleared?

--

Go to Data Link Communications System Check

--