1987 Audi 5000 CS, AutomaticFACTORY OEM SERVICE PROCEDURE

Lambda Control

Lambda control is integrated in ECU and sensor input signals. After input signals are amplified, output signal adjust differential pressure regulator.

Control range of differential pressure regulator current is 0-16 mA. Regulator pressure change at 8 mA or above.

Lambda control is non-operational under these conditions: oxygen sensor not ready for operation or defective, during deceleration shut-off, under full load conditions, during acceleration enrichment, when starting engine at coolant temperatures below 60°F (15°C) or until coolant temperature reaches 105°F (40°C).

Factory Service Tools

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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.