& Installation: ECM: Removal — 1994 Audi S4 Service Manual & Component Testing >> Removal & Installation >> ECM >> Removal Removal & Installation: ECM: Removal CAUTION: DO NOT have the (VAG 1551) Scan Tool connected at the same time as the (VAG 1598) test box. BEFORE disconnecting the ECM harness connector, switch the ignition OFF and WAIT at least 20 seconds. Failure to do so may damage the ECM. By disconnecting the Motronic ECM harness connector, the battery positive voltage supply to the permanent memory is also disconnected, which in turn erases the DTC memory. With ignition switch in OFF position. Remove cover fasteners (arrows) from lower right "A" pillar. See Fig 1. Pull back carpeting in right front foot well. Remove screws (arrows) from electronics box cover. See Fig 2. Carefully pull upper and lower cover out of electronics box. Disconnect Motronic ECM from electronics box. Remove hose clamp from vacuum line and pull vacuum line out. Fig 1: Removing The Motronic Engine Control Module (1 Of 2) [IMAGE: http://127.0.0.1:8080/images25/G00160026/] Courtesy of AUDI OF AMERICA, INC. Fig 2: Removing The Motronic Engine Control Module (2 Of 2) [IMAGE: http://127.0.0.1:8080/images25/G00160027/] Courtesy of AUDI OF AMERICA, INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Removal

Use the Manual With the Right Hardware

When to See a Mechanic