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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Escalade 🢒 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 Gas

Step

Action

Value(s)

Yes

No

1

Turn the ignition switch to the RUN position.

Does the malfunction indicator lamp (MIL) illuminate?

--

Go to Step 2

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

2
  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 3

Go to Scan Tool Does Not Communicate with Class 2 Device

3
  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 4

Go to Diagnostic System Check in Antilock Brake System

4
  1. Turn the ignition switch to the OFF position.
  2. Disconnect connector C4 from the VCM.
  3. Connect a DMM between terminal 11 of connector C4 of the VCM and splice S150.

Is continuity present?

--

Go to Step 6

Go to Step 5

5

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

Go to Step 1

6

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

Is the repair complete?

--

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

Go to Step 1

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

Step

Action

Value(s)

Yes

No

1

Turn the ignition switch to the RUN position.

Does the ABS indicator lamp illuminate?

--

Go to Step 2

Go to Diagnostic System Check in Antilock Brake System

2
  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 indicate No Communication with Vehicle?

--

Go to Scan Tool Does Not Communicate with Class 2 Device

Go to Step 3

3
  1. From the scan tool's main menu, select the Powertrain Diagnostics.
  2. Establish communication with the powertrain control module (PCM).

Is the scan tool able to communicate with the PCM?

--

Go to Scan Tool Does Not Communicate with Class 2 Device

Go to Step 4

4
  1. Turn the ignition switch to the OFF position.
  2. Disconnect connector C3 from the PCM.
  3. Connect a DMM between cavity C8 of connector C3 of the PCM and splice S150.

Is continuity present?

--

Go to Step 5

Go to Step 6

5

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls-6.5L-L65.

Is the repair complete?

--

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 6.5L

Go to Step 1

6

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 Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 6.5L

Go to Step 1