GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Catera 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Diagnostic System Check - Data Link Communications

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

With scan tool connected make contact with any of the modules applicable to the vehicle

Scan Tools main menu.
    • Blank Screen
    • No power to the scan tool

Refer to Scan Tool Inoperative .

2
  1. Establish communication with the engine control module (ECM) found in POWERTRAIN.
  2. Access DTC's using the scan tool.

No DTC's found.
    • No communication with the vehicle or the diagnostic link connector. Refer to Scan Tool Does Not Communicate with EngineControl Module
    • DTC's are present. Refer to applicable DTC list.

3
  1. Establish communication with the transmission control module (TCM) found in POWERTRAIN.
  2. Access DTC's using the scan tool.

No DTC's found.
    • No communication with the vehicle or the diagnostic link connector. Refer to Scan Tool Does Not Communicate with Transmission Control Module
    • DTC's are present. Refer to applicable DTC list.

4
  1. Select BODY DIAGNOSTICS from the scan tools menu.
  2. Select BODY CONTROL MODULE.
  3. Select DIAGNOSTIC TROUBLE CODES (DTC)
  4. Access DTC's using the scan tool.
  5. Record current and history DTC's.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or the data link connector. Refer to Scan Tool Does Not Communicate with Class 2 Data Line

5
  1. Select INSTRUMENT PANEL CLUSTER Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with Instrument Cluster .

6
  1. Select HEATING AND AIR CONDITIONING Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with Heater and Air Conditioning (A/C) Control .

7
  1. Select SUPPLEMENTAL INFLATABLE RESTRAINT Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with SDM .

8
  1. Select MEMORY SEAT MODULE Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with MSM .

9
  1. Select IMMOBILIZER Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with TDM (Immobilizer) .

10
  1. Select LEVELING SENSOR Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with Automatic Level Control Sensor .

11
  1. Select POWER ROOF Data Line information.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with Sunroof Actuator .

12
  1. Establish communication with the electronic brake traction control module (EBTCM) found in CHASSIS.
  2. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic link connector. Refer to Scan Tool Does Not Communicate with Electronic Brake and Traction Control Module .

13
  1. Select VARIABLE EFFORT STEERING.
  2. Establish communication with the power steering control module (PSCM).
  3. Access DTC's using the scan tool.

No DTC's found.
    • DTC's are present. Refer to applicable DTC list.
    • No communication with the vehicle or with the diagnostic data link connector.

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.