GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Express 🢒 DTC 🢒 DTC B1007 EEPROM Write Error

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 Intermittents and Poor Connections 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 unpowered or otherwise malfunctioning VCM.

    2.

  2. This test inspects whether the VCM is in a Fail-Enabled state.

    3.

  3. This test inspects for a wiring malfunction which would set this DTC.

    4.

  4. This test inspects for DTC B1007 or DTC U1193 which may result in DTC U1016 also being set.

    5.

  5. This test determines whether the DTC is due to a VIM malfunction.

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to

    •  Powertrain On Board Diagnostic (OBD) System Check for 7.4L in Engine Controls

2

  1. Turn the Ignition Switch to the RUN position.
  2. Observe the Powertrain Malfunction Indicator Lamp (MIL).

Is the MIL on?

--

Go to Step 3

Go to

    •  Powertrain On Board Diagnostic (OBD) System Check for 7.4L in Engine Controls

3

Attempt to start the engine.

Does the engine start?

--

Go to Step 3

Go to

    •  Powertrain On Board Diagnostic (OBD) System Check for 7.4L in Engine Controls

4

  1. Turn the Ignition Switch to the OFF position.
  2. Turn the Ignition Switch to the RUN position.

Is DTC U1016 current in any other controller?

--

Go to Step 3

Go to Step 3

5

  1. Turn the Ignition Switch to the OFF position.
  2. Repair the open in CKT 1807 between the following components:
    3. • The VCM
    • Splice S207
  3. Clear the DTCs.

Is the repair complete?

--

Go to

    •  Powertrain On Board Diagnostic (OBD) System Check for 7.4L in Engine Controls

--

6

Inspect for any other VIM DTCs.

Are any other VIM DTCs current?

--

Go to the appropriate DTC table

Go to Step 3

7
  1. Turn the Ignition Switch to the OFF position.
  2. Wait 10 seconds.
  3. Turn the Ignition Switch to the RUN position.
  4. Wait approximately 45 seconds.

Is DTC U1016 current?

--

Go to Step 3

Go to Step 3

8
  1. Turn the Ignition Switch to the OFF position.
  2. Replace the VIM.

Is the repair complete?

--

Go to

    •  Powertrain On Board Diagnostic (OBD) System Check for 7.4L in Engine Controls

--

9

Clear the DTCs.

Is the repair complete?

--

Go to

    •  Powertrain On Board Diagnostic (OBD) System Check for 7.4L in Engine Controls

--