GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The VIM calculates a checksum for the contents of the EEPROM when the voltage is first applied at terminal E. This calculated checksum is compared with the checksum value stored in the EEPROM.

Conditions for Setting the DTC

The VIM calculates a checksum for the contents of the EEPROM when the voltage is first applied at terminal E. This calculated checksum is compared with the checksum value stored in the EEPROM. If the 2 values are not equal, DTC B1007 is set. The VIM writes certain information onto the EEPROM. If the VIM is unable to write onto the EEPROM, DTC B1007 is set.

Conditions for Clearing the MIL/DTC

  1. A history DTC will clear after 100 consecutive ignition cycles occur without a fault.
  2. Use the Scan Tool in order to clear the history and the current DTCs.

Diagnostic Aids

Most intermittent faults are caused by a faulty electrical connection or the wiring. Damaged VIM modules are occasionally at fault. Refer to Intermittent and Poor Connections in Troubleshooting Procedures for a detailed explanation of how to locate and repair intermittent conditions.

Test Description

The step number(s) below refer to the step number(s) in the Loss of VCM Class 2 Communications Diagnostic Table.

  1. This test inspects for an intermittent condition.

DTC B1007 EEPROM Write Error

Step

Action

Value(s)

Yes

No

1

Was the Theft Deterrent System Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Turn ON the ignition.
  2. Clear any DTCs.
  3. Turn OFF the ignition.
  4. Turn ON the ignition.

Is the DTC still present?

--

Go to Step 3

Go to Diagnostic Starting Point

3

Replace the VIM Module. Refer to Theft Deterrent Module Replacement

Is the replacement complete?

--

Go to Step 4

--

4

  1. Turn OFF the ignition.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn ON the ignition.
  4. Clear any DTCs.

Are all DTCs cleared?

--

Go to Diagnostic System Check - Theft Deterrent

--