MRC Chips for the Audi urS-cars

ECU Swapping 101

Getting to the ECU

The ECU is located under the sloping portion of the right front floor of the passenger compartment.

1.  Pop out the rubber trim strip in the RF door sill and remove the three Phillips screws thus exposed. This allows the front end of the sill plate to be lifted and swung in toward the center console.

2.  Using a small sharp tool (a small screwdriver or a knife tip or the like) pop out the button just above floor level and just in front of the door opening and remove the screw thus exposed. This will allow pulling the trim piece away from the side of the car.

3.  Remove this trim piece. It is held in place by the screw just removed and friction clips up along the gap between the dash and the RF door. Just pull firmly but gently and the trim will come out.

4.  Using a sharp knife, cut the carpet at the junction between the center console and the sloping portion of the floor from top to the bottom of the sloping floor. This will allow folding the carpet back to expose the flooring beneath the carpet.

5.  The plastic plates thus exposed cover the ECU. Remove the screws holding the plates in place and then remove the plates. Pay attention to the manner in which they come out because they need to go back in the same way.

6.  The ECU is now exposed. It is held in place with four screws, one at each corner. Remove these screws and lift the ECU out of its compartment.

7.  The ECU remains, at this point, connected to the car by its wiring harness and the MAP hose. Unclamp the hose so that it may be removed from its connection and disconnect the harness. There is a metal locking device which must be pulled out before the harness plug will separate from the ECU’s connectors.

8.  The ECU may now be removed from the car and the replacement ECU with its new mods may be put in its place.

As is said in the trade, reassembly is the reverse of disassembly. ;-)
130 MPH Speed Limiter
While removing the 130 MPH Speed Limiter for highway use is strongly discouraged if the car is intended for track use where extremely high speeds are appropriate then removal of the limiter makes sense. The limiter is a red “relay” which you will see above the hole for the ECU. Simply unplugging the box from its pigtail harness eliminates the speed limiter function. Replace the limiter in the pocket where it was found so that it may be reconnected when/if you sell the car. If you do not plan on running the car on the track it is strongly recommended that you leave the Speed Limiter installed.

Remember – Speed is a serious thing!
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