GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy C Pickup - 2WD 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Scan Tool Does Not Communicate with Vehicle Control Module/Powertrain Control Module

Scan Tool Does Not Communicate with Vehicle Control Module/Powertrain Control Module Vehicle Control Module

Step

Action

Value(s)

Yes

No

1

Did you perform the Data Link Communications Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Data Link Communications

2

Turn the Ignition Switch to the RUN position.

Does the Malfunction Indicator Lamp (MIL) illuminate?

--

Go to Step 3

Go to Powertrain On Board Diagnostic (OBD) System Check (5.0L/5.7L) or Powertrain On Board Diagnostic (OBD) System Check (7.4L) in Engine Controls

3
  1. From the scan tool's main menu, select Powertrain Diagnostics.
  2. Establish communications with the Vehicle Control Module (VCM).

Does the scan tool indicate "No Data Communication with Vehicle"?

--

Go to Step 4

Go to Diagnostic System Check - Data Link Communications

4
  1. From the scan tool's main menu, select Chassis Diagnostics.
  2. Establish communications with the Electronic Brake Control Module (EBCM).

Is the scan tool able to communicate with the EBCM?

--

Go to Step 5

Go to Diagnostic System Check - Data Link Communications

5
  1. Turn the Ignition Switch to the OFF position.
  2. Disconnect connector C4 from the VCM
  3. Connect a J 39200 DMM between terminal 11 of connector C4 of the VCM and splice S150.

Is continuity present?

--

Go to Step 7

Go to Step 6

6

Locate and repair the open or cause of resistance in CKT 1807 (PPL) between splice S150 and terminal 11, connector C4 of the VCM. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

7

Replace the VCM. Refer to VCM Replacement/Programming (5.0L/5.7L); VCM Replacement/Programming (7.4L) in Engine Controls.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

Scan Tool Does Not Communicate with Vehicle Control Module/Powertrain Control Module Powertrain Control Module

Step

Action

Value(s)

Yes

No

1

Did you perform the Data Link Communications Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Data Link Communications

2

Turn the Ignition Switch to the RUN postion.

Does the ABS Indicator Lamp illuminate?

--

Go to Step 3

Go to Diagnostic System Check - ABS

3
  1. From the scan tool's main menu, select the Chassis Diagnostics.
  2. Establish communication with the Electronic Brake Control Module (EBCM).

Does the scan tool inidicate "No Communication with Vehicle"?

--

Go to Diagnostic System Check - Data Link Communications

Go to Step 4

4
  1. From the scan tool's main menu, select Powertrain Diagnostics.
  2. Establish communication with the Powertrain Control Module (PCM).

Is the scan tool able to communicate with the VCM?

--

Go to Diagnostic System Check - Data Link Communications

Go to Step 5

5
  1. Turn the Ignition Switch to the OFF position.
  2. Disconnect connector C3 from the PCM.
  3. Connect a J 39200 DMM between cavity C8 of connector C3 of the PCM and splice S150.

Is continuity present?

--

Go to Step 6

Go to Step 7

6

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--

7

Locate and repair the open or cause of resistance in CKT 1807 (PPL) between splice S107 and the EBCM. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - Data Link Communications

--