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PCMTec Editon Required: Professional, One-Car Workshop, or Workshop.
This guide explains the steps to follow when replacing a failed PCM.
The only PCMs we have seen fail to date are very early BAs which appear to start resetting when very hot or cold which we believe is due to cracks appearing in the PCB. We have also rarely seen injector drivers fail, usually, this is due to a failed injector shorting out.
Before assuming a failed PCM do a KAM reset (performed automatically when writing a file to the PCM via PCMTEC) and check your power/ground sources.
If the vehicle has had an engine swap please ensure that you have continuity in your CAN Bus and all grounds are clean.
If you have diagnosed a PCM failure you must replace the PCM with the same part number such as ASU-234 etc. Some part numbers are compatible with others however they will be missing IO. Eg an NA 6-cylinder PCM will work in a turbo vehicle, however, the wastegate output will not function. The same goes for an 8-cylinder PCM will sometimes work in a 6-cylinder vehicle, but the reverse is not true. To ensure the PCM is compatible with your vehicle we recommend purchasing an identical hardware model.
If your PCM has a CustomOS Installed, there are extra steps required. Please see the specific CustomOS replacement PCM guide here.
Step 1:
Read the existing old PCM and save it to disk. Ensure you have ticked "PCM" within the flash read page. If the PCM was erased at any stage you can still do this step, but you will need to use recovery mode and manually select the PCM type from the corresponding dropdowns. E.g. for BA select Black Oak, and for BF/FG select Spanish Oak.
This file does not need to be licensed.
Save this read as "Old PCM.tec"
Step 2:
Install the new PCM.
Read the new PCM only by ensuring PCM is ticked within the flash read page.
Save this as "new PCM.tec" and do not license the file.
Step 3:
Open the merge wizard via "Create Stock File/Calibration Merge".
Select "Manually Merge VID/Serial".
Press "Load File 1" and select "Old PCM.tec". Press "Load File 2" and select "new PCM.tec".
Next press "Import PCM Serial from File 2".
Press "Save File 1" and save as "Old PCM with new PCM serial.tec".
Step 4:
Now license the file again (will cost 3 credits to license the new file) and write the file to the vehicle.
Step 5:
Once you have written the previous calibration to the vehicle the vehicle will be immobilised and will not start. To reset the security system a procedure called a "Parameter Reset" is required.
This last step we cannot warranty and is out of the scope of our support however there are several packages that can do this for you.
FORScan ( www.forscan.org ) is free and can do this for most but NOT ALL Fords. The procedure is located under "service procedures".
If your vehicle is not supported by Forscan you can also use some high end scan tools or Ford IDS/FDRS to perform this step. If you do not have access to either of these you will require a Ford service centre to do it for you. Depending on which state you are in there are several people who can come to you to do this for a fee.
It is not necessary to erase or reprogram keys as part of this process.
Note you can disable PATS to allow the car to be started and drive it to a workshop. This is a temporary measure as by disabling PATS your radio and instrumentation will stop working. In some BAs the radio will continue to work with PATS disabled however it is best to assume that there will be side effects.
A guide to replace the ZF Transmission (or just the TCM) can be found here.
