Programming and Relearning

FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM)

Description
Flash EEPROM is contained in an integrated circuit internal to the powertrain control module (PCM). The flash EEPROM contains the vehicle strategy, including calibration information specific to the vehicle, and is capable of being reprogrammed or reflashed repeatedly.

As part of the calibration there is an area referred to as the vehicle identification (VID) block in the PCM. The VID block must be programmed when installing a new PCM as described under Programming the VID Block for a New PCM. Not carrying out this procedure may generate DTCs: P1635, P1639, VID Block not programmed or is corrupt. The VID block in an existing PCM can also be tailored to accommodate various hardware/parameter changes made to the vehicle since production. Not carrying out this procedure correctly may generate DTC P1635, Tire/Axle Ratio out of Acceptable Range, is one of the main causes for DTC P1639. This is described under Making Changes to the VID Block, and also under Making Changes to the PCM Calibration. The VID block contains many items used by the strategy for a variety of functions. Some of these items include the vehicle identification number (VIN), octane adjust, fuel octane, fuel type, vehicle speed limit, tire size, axle ratio, the presence of speed control, and four wheel drive electronic shift-on-the-fly (ESOF) versus manual shift-on-the-fly (MSOF). Only items applicable to the vehicle hardware and supported by the VID block are displayed on the scan tool.

When changing items in the VID block, the strategy places range limits on certain items such as tire and axle ratio.

Each of the procedures described below use the scan tool. Reprogramming can be carried out by a local Ford dealer or any non-Ford facility. There are other enhanced scan tools that may have reprogramming capabilities available. Refer to the scan tool manufacturer's manual for details.

Programming the VID Block for a New PCM
A new PCM contains the latest strategy and calibration level for a particular vehicle. However, the VID block is blank and needs programming. There are 2 procedures available. The first is an automatic data transfer from the old PCM to the new PCM, and the second is manual data entry into the new PCM.

Automatic data transfer is carried out if the old PCM is capable of communicating. This is done by the use of a scan tool to retrieve data from the old PCM before removing it from the vehicle. The stored data can be downloaded to the new PCM after installation.

Manual data entry must be carried out if the old module is damaged and incapable of communicating. Install a new PCM. Using a compatible scan tool, select and execute Module/Parameter reprogramming referring to the manufacturer's user manual. Make certain that all parameters are included. Incorrectly programming tire size in revolutions per mile, (rev/mile - 63,360 divided by the tire circumference in inches), Axle Ratio, 4x4/4x2, and MSOF/ESOF may result in DTCs P1635 or P1639. You may be instructed to contact the As-Built Data Center for the information needed to manually update the VID block with the scan tool. Contact the center only if the old PCM cannot be used or the data is corrupt. For Ford Lincoln-Mercury technicians, contact your National Hotline or the Professional Technician Society (PTS) web site for as-built data. Non-Ford technicians, use the Motorcraft website at motorcraft.com. From the Motorcraft homepage, use the search function to find the Module Programming or As-Built Data.

Making Changes to the VID Block
A PCM which is programmed may require changes to be made to certain VID information to accommodate vehicle hardware. Refer to PCM/Module Reprogramming on the scan tool.

Making Changes to the PCM Calibration
At certain times, the entire flash EEPROM needs to be completely reprogrammed. This is due to changes made to the strategy or calibration after production. Refer to PCM Reprogramming on the scan tool.