Chevy Suburban
Jeep Cherokee Laredo
Mitsubishi Lancer
Toyota RAV4

Where or how do you replace or remap an ECU on a Mitsubishi 2003 lancer OZ?

Answer

User Avatar
Wiki User
02/26/2008

THIS ANSWER IS INTENDED TO HELP YOU REMOVE THE ECU SO THAT A REPLACEMENT CAN BE INSTALLED. THE ONLY WAY TO REMAP AN ECU IS TO HAVE A MITSUBISHI DEALERSHIP OR A FOREIGN CAR MECHANIC REMAP IT FOR YOU BECAUSE I HAVE NEVER HEARD OF A REMAPPING PROCESS WITHOUT INSTALLING AN AFTERMARKET PROCESSOR THAT IS DESIGNED FOR YOUR MODEL LANCER. AFTERMARKET PROCESSORS WILL ALLOW YOU TO ADJUST THE SETTINGS AND DO MANY DIFFERENT THINGS TO YOUR IMPROVE YOUR ENGINE PERFORMANCE BY USING A LAPTOP OR A HANDHELD PROGRAMMER. ***TOOLS NEEDED: 1/4" DRIVE RATCHET, 1/4" DRIVE 10MM SOCKET, 1/4" ADAPTER AND A SHORT EXTENSION*** The first step that I always take when working on any electrical or electronic part is to remove the negative battery terminal off of the battery with a 10mm socket or wrench. The ecu is located behind the glove compartment on the passenger's side of the dash board. To get to the ecu wiring, you have to remove the plastic protective cover that is underneath the passengers side dash near the console. To remove this cover you have to pull it toward the seat. It should come out rather easy. After it is removed, you should be able to see the ecu wiring harnesses. There are four connectors, varying in size and are yellow or white in color. To remove theses connectors, press the tab located on the cabin side of the connector and pull straight down. (NOTE: This can be very hard to do because the connectors could be stuck in place. Be very careful not to pull so hard that the connector releases and you severe a wire or break the connector all together as this could be very, very expensive!) Disconnect all of the connectors following the procedure listed above. Once all of the wiring connectors are removed, you are ready to remove the ecu. This will require you to remove the glove compartment to gain access to the screws that secure it in place. First, you will need to empty the glove compartment and then locate the removeable brace on the back left side. This is the piece the rests against the dash that outlines the glove compartment when closed. Reach inside and while holding the compartment slightly closed, push inward to unsecure the piece and then pull it out. Now push the back of the storage section of the glove compartment to the left just enough to get the other side around the dash on the right side. The compartment should be able to fall freely and hang upside down. Now you can unhook the hinges by lining up the open sections and pulling it off. Now you should be able to see two or three screws that secure a bracket for the ecu in place. (You can trace the ecu straight up and see the brackets and the screws. They are very obvious and easy to remove.) Remove the screws and pull the ecu out from under the dash. You will have to turn it and rotate it a little to get it out, but it is fairly easy to remove. Now you should examine the new ecu to make sure that the model numbers match as well as making sure that everything is present on the new one as well. On some replacement ecu's, the bracket has to be changed out. Install the new ecu by putting it back in it position with the wiring connections facing down and reinstalling the securing bolts, tightening them until they are snug. The wiring connectors are unique in size and have slots on them that will only connect to one slot. Replace each connector by placing them in the proper slot and pushing up until you hear a clicking sound that lets you know it is securely fastened. After all of your wiring connections are connected, reinstall the glove compartment by lining up the hinges and getting the piece back inside the dash by pushing the back to the left and pushing it inward. Now replace the removeable piece by placing it through the open slot on the back left corner and pushing it in. Reconnect the Negative battery terminal and, without starting the engine, turn the key on and check to see that everything inside the car is working. Let the car sit in this position for two to three minutes to make sure that nothing happens to your accessories i.e guages, lights stereo, etc. If everything is good, turn the key off and then start the engine (pray) without giving it any throttle. Let the engine run at idle for a while to give the ecu time to locate and recognize all of its parts and systems and set the parameters for each. If any problems are present, they will present themselves during this time period. After 10 to 15 minutes, take the car for a test drive around the block making sure to drive it for 5 or 10 minutes to ensure proper operation at regular speeds (25 to 55 mph). If it runs okay, you might want to take it out for a test run on the interstate or a main highway where you can achieve higher speeds (55 to 75 mph) to ensure proper operation. If at anytime the Service Engine Soon or the Engine shaped light comes on, stop immediately and take your vehicle to the nearest place available to have a diagnostics ran to pull the engine codes. (I believe that Autozone will hook your vehicle up to their diagnostics computer, pull the codes and give you a general idea as to the nature of the problem.) You should be able to get back to driving your vehicle now, so thank you for using my answer to the question!