GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy P12 Chassis 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Scan Tool Does Not Communicate with Electronic Brake Control Module

Step

Action

Value(s)

Yes

No

1

Was the Data Link Communications System Check performed?

--

Go to Step 2

Go to Data Link Communications System Check

2
  1. Inspect the data link connector (DLC) and repair any damaged terminals if required.
  2. Verify that the Scan Tool is firmly connected to the DLC.
  3. Turn the ignition switch to the RUN position.
  4. Attempt scan tool communications with the electronic brake control module (EBCM).

Can communications be established?

--

System OK

Go to Step 3

3
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the powertrain control module (PCM) connector C 2.
  3. Disconnect the EBCM connector C 1.
  4. Connect a J 39200 DMM on the DLC from terminal 2 to terminal 4.
  5. Measure the resistance.

Is the resistance greater than the specified value?

10M ohms

Go to Step 5

Go to Step 4

4

Locate and repair the short to ground in CKT 1807 (PPL).

Is the repair complete?

--

System OK

--

5

Use a J 39200 DMM to measure the resistance on the DLC from terminal 12 to terminal 4.

Is the resistance greater than the specified value?

10M ohms

Go to Step 7

Go to Step 6

6

Locate and repair the short to ground in CKT 799 (TAN/WHT).

Is the repair complete?

--

System OK

--

7
  1. Turn the ignition switch to the RUN position.
  2. Use a J 39200 DMM to measure the voltage on the DLC terminal  2 to terminal 4.

Is the voltage greater than the specified value?

1.0 V

Go to Step 8

Go to Step 9

8

Locate and repair the short to B + in CKT 1807 (PPL).

Is the repair complete?

--

System OK

--

9

Use a J 39200 DMM to measure the voltage on the DLC from terminal 12 to terminal 4.

Is the voltage greater than the specified value?

1.0 V

Go to Step 10

Go to Step 11

10

Locate and repair the short to voltage in CKT 799 (TAN/WHT).

Is the repair complete?

--

System OK

--

11
  1. Turn the ignition switch to the OFF position.
  2. Use a J 39200 DMM to measure the resistance from the DLC terminal 2 to the PCM connector C 2, cavity 58.

Is the resistance greater than the specified value?

1.0 ohms

Go to Step 12

Go to Step 13

12

Locate and repair the open in CKT 1807 (PPL).

Is the repair complete?

--

System OK

--

13

Use a J 39200 DMM to measure the resistance from the DLC terminal 2 to the EBCM connector C 1, cavity G.

Is the resistance greater than the specified value?

1.0 ohms

Go to Step 14

Go to Step 15

14

Locate and repair the open in CKT 1807 (PPL).

Is the repair complete?

--

System OK

--

15

Use a J 39200 to measure the resistance from the DLC terminal 12 to the EBCM connector C 1, cavity F.

Is the resistance greater than the specified value?

1.0 ohms

Go to Step 16

Go to Step 17

16

Locate and repair the open in CKT 799 (TAN/WHT).

Is the repair complete?

--

System OK

--

17
  1. Connect the PCM.
  2. Connect the EBCM.
  3. Turn the ignition switch to the RUN position.
  4. Install a scan tool.
  5. Attempt to establish communications with the EBCM.

Can communications be established?

--

System OK

Go to Step 1