For 1990-2009 cars

### Circuit Description

As part of normal data processing, the module performs a data programming check on its writes to the electrically erasable read only memory (EEPROM). The EEPROM write error detection is handled inside the control module. No external circuits are involved.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1007 EEPROM Write Error

### Conditions for Running the DTC

The module runs the program to detect an EEPROM write error. The only requirements are battery positive voltage and ground. This program runs even if the battery positive voltage is out of the valid operating range.

### Conditions for Setting the DTC

The module writes information to a data block in the EEPROM. The module then reads the data and compares it to what was sent to the data block. If the data does not match after 3 consecutive attempts, the module sets the DTC.

### Action Taken When the DTC Sets

The module writes to another area of the EEPROM, this becomes the new permanent area to store the data. The data location is allowed to change until all of the available EEPROM is used. If a DTC B1004 is also set, the module reverts to base operation values programmed for those blocks of data that have failed. The blocks of data that have not failed the checksum test are not affected.

### Conditions for Clearing the DTC

• | A current DTC clears when the malfunction is no longer present.

• | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

### Diagnostic Aids

• | This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

• | If this DTC is retrieved as both a current and history DTC, replace the module.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Retrieve the DTCs.

Is DTC retrieved as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3 | Replace the module setting the DTC as current. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 4 | --
4 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK