GM Service Manual Online
For 1990-2009 cars only

Object Number: 33013  Size: SF
Engine Controls Components
4.3L VCM, DLC, FUSE, MIL, EBCM
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

This diagnostic will detect a serial data malfunction which could inhibit the transfer of ABS rough road data to the VCM. DTC P1381 is a type D DTC.

Action Taken When the DTC Sets

The Malfunction Indicator Lamp (MIL) will not be illuminated. A history DTC P1381 will be stored.

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

Number(s) below refer to the step number(s) 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 DTC(s) use the scan tool to record Freeze Frame and Failure Records for reference, as data will be lost when the Clear Info function is used.

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

--

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

2

  1. Disconnect the VCM and 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 Antilock Brake System (ABS)

3

Repair as necessary.

Is the action complete?

--

Go to Step 4

--

4

  1. Using the scan tool, select DTC, Clear Info.
  2. Start the engine and idle until normal operating temperature is reached.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. 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, Review Info.

Are any additional DTCs displayed that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK