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.
1994 Audi 90 CS QuattroFACTORY OEM SERVICE PROCEDURE
Engine Controls - System/Component Tests
- Introduction
- Air Induction System
- Engine Sensors & Switches
- Notes
- A/C Compressor On Signal (With ECM "A")
- A/C Compressor On Signal (With ECM "B")
- A/C Compressor Cut-Out Signal (With ECM "A")
- A/C Compressor Cut-Out Signal (With ECM "B")
- Camshaft Position (CMP) Sensor
- Closed Throttle Position (CTP) Switch
- Crankshaft Position (CKP) Sensor
- Engine Coolant Temperature (ECT) Sensor
- Engine Speed (Rpm) Sensor
- KICKDOWN Switch
- Mass Airflow Sensor (With ECM "A")
- Mass Airflow Sensor (With ECM "B")
- Oxygen Sensor (O2S) Heating Element
- Oxygen Sensor (O2S) Control
- Throttle Position (TP) Sensor
- Relays & Solenoids
- Fuel System
- Idle Control System
- Ignition System
- Emission Systems & Sub-Systems
- Throttle Controls
Factory Service Tools
Use the Manual With the Right Hardware
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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.