Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
MOTRONIC Management System (MMS): 2.8L
A4 models are equipped with MMS 410. Cabriolet models are equipped with MMS 411. MMS is controlled by the Powertrain Control Module (PCM). The MMS has fully adaptive oxygen sensor control for mixture control and also controls ignition system. A Mass Airflow (MAF) sensor is used without a CO adjustment potentiometer. CO adjustment is not possible.
Input and output signals from various sensors, switches and signaling devices are constantly monitored for engine control and trouble codes. If trouble code(s) occur, they are stored in memory. Trouble codes can be displayed by a flashing 4-digit code sequence from a Malfunction Indicator Light (MIL), located in the instrument cluster.
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Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.