The single fact that this modification is possible is perhaps the main reason that the Volkswagen/Audi 1.8T is so popular. In a nutshell, a simple chip swap for the engine’s computer unleashes a power increase of about 25 percent, without having to make any additional changes to the car.
Thus, despite being a small-displacement engine, and despite the fact that larger engines are available in most of the same chassis, the 1.8T can easily be tuned to deliver equal or greater power than those larger engines, thus providing a lighter, cheaper solution for enthusiast owners. Plus, because a chip swap is so non-invasive, and inexpensive, in relation to the power that is gained, it’s a no-brainer for almost any 1.8T owner. The main consideration is that your car will be out of commission while the ECU is out, so you must plan for that.
The ECU is pretty easy to access and remove. The hard work of this project is done by the vender of your chip. Once you extract the ECU from your car, you pack it up and ship it to them. The vendor removes the factory chip, replaces it with the new chip, and sends it back to you. The new chip contains custom programming that increases the turbo boost the engine sees; in addition, it directs changes to the fuel injection and ignition timing to make the most of that additional boost, increasing performance substantially yet within the limits of the car’s stock components. And yes, a custom tune combined with an upgraded turbo, injectors, intercooler, and/or fuel injectors can make even more power.
Remember to disconnect your battery at the negative terminal before you start, and you should have the job done in 15-20 minutes.
You will need to remove the wiper arms in order to remove the panel that covers the ECU box. It’s easiest to do this by “parking” the wipers in the up position. Simply kill the ignition when the wipers are where you want them. Then, disconnect your battery at the negative terminal.
The ECU resides under the plastic cowl cover that spans the area between the engine firewall and the base of the windshield. Refer to the cabin filter replacement article for a more detailed examination of this panel; if you’ve removed it before, it should be easy to do it again. Start by removing the rubber
weather-stripping at the leading edge of the cowl cover.
To access all of the bolts holding the lid on the ECU enclosure, remove the plastic cover at the base of the windshield. The lower windshield cover is split into two pieces
- you only need to remove the half on the driver’s side. Start by removing the trim clips. Next, two Phillips-head fasteners help hold the piece to the bottom of the windshield. Turn these 1/4 turn counter-clockwise to release them
Use a 13 mm socket to loosen and remove the nut from the wiper pivot. Lift the wiper arm away from the windshield to release the tension pressing the wiper arm to the pivot, which should make it easy for you to lift the arm off of the pivot. These get tightened to 12 ft-lbs when you reattach them.
The ECU has two multi-pin connectors. No need to pull or twist them; simply pull the clip for each connector away from the ECU. The connector is equipped with a mechanism that will push it away from the ECU as you pull the clip away.
The clip should have more than an inch of travel, and the connector should automatically release from the ECU. Here you can see the extend of travel of the connector clip. Do the same for each of the two connectors.
Comments: I have a a4 1.8t manual took it into audi they say its running 3 cylinders and i need a new ecu they r goin to over charge me for it of coarse so i said ill try and find 1 on ebay then they said it needs to be these numbers here8d0907557cx or 8d0997557t looked everywhere buy couldnt find then audi said they have to australian marketed , does these numbers exist
October 20, 2014
Followup from the Pelican Staff: I don';t have access to cross-reference the numbers. Give our parts specialists a call at 1-888-280-7799. They can help you find the right part.
- Nick at Pelican Parts
Comments: Thanks for your answer. ECU and DME are the same? If they are failling, there must be registered fault codes?
August 28, 2014
Followup from the Pelican Staff: Yes DME can be ECU. There may not be fault codes stored. - Nick at Pelican Parts
Comments: Hi. I have a 1998 Audi A4 1.8T with immobilizer problem that prevent engine starting sometimes. I know that the antitheft software is located in the ECU, so can I disable the immobilizer or antitheft system inside ECU? Thanks for your help
August 27, 2014
Followup from the Pelican Staff: It can't be disabled. The issue could be in the DME or the instrument cluster. Check the vehicle for fault codes. - Nick at Pelican Parts
Comments: I have a Chrysler Sebring 2.0 diesel 2008 car. I get a noise coming from the ECU after the engine is switched off. Sometimes it sounds like a buzz or some kind of depressurization. When I put my hand over it I can actually feel the vibrations coming from the unit. Close by is the abs pump but no vibration or sound comes from it. ECU P/N 0533700AF
June 17, 2014
Followup from the Pelican Staff: The vibration is normal, it is from the ABS control unit. - Nick at Pelican Parts
Comments: Pls help. I own an '02 vw jetta. Immobilizer nightmare. VAGCOM is throwing a mess. Stating ECU disconnected.??? Severak guys have checked all fuses.Afraid someone may have accidentally bumped sonething while underneith steering column. I know where ECU is located don't know where to check the connection. Trying to reprogram new vw valet key just bought from dealer, we erased alk codes...still saying ABS & AIRBAG NO CONNECTIOn.??,,, PLEASE PLEASE HELP. ME
April 14, 2014
Followup from the Pelican Staff: What fault codes do you have? Can you share the complete scan of the vehicle? It's possible you have a bus problem or the ECU is faulty. - Nick at Pelican Parts
Comments: do I need password to program ECU?
March 27, 2014
Followup from the Pelican Staff: You may need a PIN. Depends on the year. - Nick at Pelican Parts
Comments: so you think it would work just need keys/immobilizer programming?? or is it a wild guess
November 12, 2013
Followup from the Pelican Staff: You will need to program the new VIN so it matches in the modules involved with anti-theft. Which requires a security pin number. This number is tough to obtain. Locksmiths and the factory use to have access to it. I believe locksmiths still can get it. The dealer no longer sees the number, it is all done via pass-thru programming. Hope this information helps answer your question.- Nick at Pelican Parts
Comments: hi does any know, I have a 1.8t Passat 02 reg 150 bhp will the audi tt225 ecu plug in is the wiring the same I now of a injector change plus possible key programme any help would be appreciated thanks in advance, dan
November 10, 2013
Followup from the Pelican Staff: If it plugs in, it won't run. The VIN is programmed into the ECU, the antitheft software won't allow it to start.- Nick at Pelican Parts
Comments: I now have my ECU out of my Audi TT mk1, it's still sending messages but is give electrical engine faults. I lol now if these problems in the TT mk1 but is it repairable??
August 19, 2013
Followup from the Pelican Staff: I don't understand your question. I can try to answer it. If the ECM is faulty, it may be able to be repaired by an ECM repair company. - Nick at Pelican Parts
Comments: My current ECU is not working properly...can I use a different chip or get a new ECU for my 2001 audi A6
July 20, 2013
Followup from the Pelican Staff: We don't carry an aftermarket chip for your A6, although there may be some Audi aftermarket suppliers that make one. You can certainly get a new ECU if yours in not working properly. -
Comments: Whaat kind of car was on that picture because i know its not a passat.
November 15, 2012
Followup from the Pelican Staff: The vehicle:
Trim Level: 1.8T quattro
Body Type: 4 Door Sedan
Fuel Type: Turbo
- Nick at Pelican Parts
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