GM Service Manual Online
For 1990-2009 cars only

Object Number: 56430  Size: SF
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
Engine Controls Components
Transmission Shift Controls
OBD II Symbol Description Notice

Circuit Description

This diagnostic detects a serial data malfunction which could inhibit the transfer of the ABS rough road data to the VCM. This DTC is a type D DTC.

Conditions for Setting the DTC

Test Conditions

  1. The DTC P0300 is set, and the DTC P0300 is requesting the MIL ON.
  2. No rough road data is available from the EBCM.

Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will not illuminate. The VCM stores a history DTC.

Conditions for Clearing the MIL/DTC

The VCM turns OFF the MIL after 3 consecutive driving trips without a fault condition present. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (the coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle) or the scan tool clearing feature has been used.

Test Description

The number below refer to the step number on the diagnostic table.

  1. This step isolates an open serial data circuit from the EBCM system.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing the DTCs use the scan tool in order to record the Freeze Frame and the Failure Records for reference because the Clear Info function will lose the data.

Was the On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Disconnect the VCM and the EBCM.
  2. Check the serial data circuit between the VCM and the EBCM for an open.

Was a problem found?

--

Go to Step 3

Go to Section 5E1 Antilock Brake System (ABS)

3

Repair the problem as necessary.

Is the action complete?

--

Go to Step 4

--

4

  1. Using the scan tool, select DTC and Clear Info.
  2. Start the engine.
  3. Idle until the engine reaches the normal operating temperature.
  4. Select DTC and Specific.
  5. Then enter the DTC number which was set.
  6. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic Ran and Passed?

--

Go to Step 5

--

5

Using the scan tool, select Capture Info and Review Info.

Are any additional DTCs displayed that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK