GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules.

Conditions for Running the DTC

    • Voltage supplied to the module is in the normal operating voltage range (approximately 9-16 volts).
    • Diagnostic trouble codes U1300 and U1301 do not have a current status.
    • The vehicle power mode (ignition switch position) requires serial data communication to occur.

Conditions for Setting the DTC

The VIN information stored in the BCM and in the PCM do not match.

Action Taken When the DTC Sets

The SERVICE VEHICLE SOON telltale illuminates.

Conditions for Clearing the DTC

    • A current DTC B1015 will clear if the malfunction is no longer present and a scan tool is used to clear the DTC.
    • A history DTC B1015 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present or if a scan tool is used to clear the DTC.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks to see if the correct VIN information is in the BCM.

  2. This step checks to see if the correct VIN information is in the PCM.

Step

Action

Value(s)

Yes

No

1

With a scan tool, observe the (VIN) in the BCM, New VIN function, which resides in the Special Functions menu.

Does the scan tool display the correct VIN information?

--

Go to Step 2

Go to Step 3

2

With a scan tool, observe the (VIN) in the PCM ID Information menu.

Does the scan tool display the correct VIN information?

--

Go to Step 4

Go to Step 5

3

With a scan tool, enter the correct VIN information into the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Did you complete the repair?

--

Go to Step 6

--

4

  1. Replace the BCM. Refer to Body Control Module Replacement .
  2. Perform the Setup procedure for the new BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Is the repair complete?

--

Go to Step 6

--

5

Reprogram the PCM. Refer to Powertrain Control Module Replacement (3.1) in Engine Controls.

Is the repair complete?

--

Go to Step 6

--

6

Operate the vehicle within the conditions for running the DTC.

Does the DTC reset?

--

Go to Step 1

System OK