Computer Location

Helpful Links

  • OBD1 Computer Location List

  • OBD2 Computer Location Pictures

  • Instructions for PCM installation, PROM and MEMCAL removal and reinstallation, and for passkey instructions when replacing a computer that was not originally from your vehicle.

  • Vehicle Identification Numbers to view PDF on understanding VINs. If you're not sure what year your vehicle is, include the VIN on your order form.



Attention: The 3 or 4 digit alpha numeric values are what we need to build your chip. This information is on the connector end of the computer above the UPC bar code. Here's a more comprehensive list and some pictures of example labels showing the information we need.

The computer is a large silver box with one large rectangular connector of 60 to 120 pins. Truck computer locations vary from behind and left of the park brake bracket, to the passenger side kick panel or above the right side kick panel. Car locations vary from under drivers' dash, passenger kick panel, and above and rearward of the glove box.

Prior to ECU removal:

1st - Remove the ignition key from the ignition cylinder. Disconnect the battery negative terminal.

2nd - Disconnect the main connector with a 10 mm socket from the firewall/bulkhead side and gently slide the connector away from the computer.

3rd - Remove the computer - in most gas trucks from the above passenger side dick panel after the plastic retaining clip is removed, the computer will almost fall out.

- 1998-2003 diesel computers are inside the black plastic sleeve near the park brake bracket.
- 2003+ computers for the diesels are beside the battery.
- 2008+ 6.4TD are at the passenger side bulkhead.
- We now mainly concentrate on 1996 and up Ford products and no longer support the older models other than some of the older Mustangs. With our DPS-Ford system, removing the computer is no longer necessary as we can reflash the computer directly.

The 1996-2010 Ford codes are directly above the UPC stamp on the white label which is glued to the ECU connector, and on a black plastic cover on the computer J3 port. Ford codes are always 3 letters and 1 number. ANY OTHER NUMBERS are not needed for your order unless mentioned on the order page.


General Motors

Computer locations may vary...

1982-1995 Car Locations vary from behind the glove box, above the glove box, under the passenger side dash, under the hood at the right strut tower, the right side kick panel.

1984-1988 Pontiac Fiero computers are located rearward between the seats.

1987-1995 GM Truck computers are always behind the glove box (4.3, 5.0, 5.7, 6.5TD, 7.4). Look for a silver box with two or three connectors. The computer often has a white label which indicates computer service number and 4 letter code. To verify the code, always remove the computer cover (two 1/4" screws) and note the label directly on the computer chip. The computer code always has 4 letters on the computer white label tag (Service #1227747 code ANLW), or right on the prom itself. This code is required for all 1982-1995 GM computer reprogramming as we alway prefer to work from the original calibration rather than supply a 'generic-one-size-fits-all' calibration.

Most Astro Van ECM's are behind the passenger kick panel or under the hood (after 1995).

1992-1995 Cadillac is always under the passenger side dash.

Once you find your 1987-1995 GM computer, locate the box "code" and include it on your order form!

1996-2010 computers (VCM/TCM/PCM) are normally located under the hood, except in the case of some V6 cars (under the drivers side dash).


If you're unable to find your computer after checking the Computer Location page, just call, email, or fax us. We'll guide you through the process.

Wester's Garage ... We'll get YOU going FAST!!
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Wester's Garage 2020
Updated 01/2020 ru

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