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Home >> Audi >> 1989 >> 80 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> System/Component Tests >> Fuel System >> Fuel Control (Cis Digital Control) >> OXS Frequency Valve
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OXS Frequency Valve

  1. Disconnect harness connector from OXS frequency valve. Using a LED Test Light (US 1115), connect Red lead to terminal No. one and Black lead to terminal No. 2.
  2. Perform output code self-diagnosis as previously described. When code appears, LED test light must be off. If light is off, replace OXS frequency valve.
  3. If light came on, ensure 12 volts are present between oxygen sensor terminal No. 1 and ground. If necessary, repair wiring or circuits.
  4. If 12 volts are present, turn ignition off. Disconnect ECU harness connector. Check for about 10 ohms in wire between ECU terminal No. 8 and oxygen sensor terminal No. 2. See Figure . If ohms are not as specified, check for an open circuit in wire. If circuit is not open, replace ECU.