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Home >> Audi >> 2012 >> A8 Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> 4.2L - Generic Scan Tool - Engine Code: CDRA (2 Of 2) >> St Generic Scan Tool >> Diagnosis And Testing >> Diagnostic Procedures >> Secondary Air Injection Combination Valve, Checking

Secondary Air Injection Combination Valve, Checking

Observe all safety precautions: SAFETY PRECAUTIONS

View clean working conditions: CLEAN WORKING CONDITIONS

Special Tools And Workshop Equipment Required 

Test conditions

Test procedure

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start procedure

-- Remove the vacuum hose from the combination valve.

-- Connect hand vacuum pump to combination valve vacuum connection.

-- Remove the air duct hose from the Throttle Valve Control Module -J338- and position aside.

-- Disconnect the Secondary Air Injection hose.

-- Inject a light air pressure into the in Secondary Air Injection hose to close the combination valve. (do not use compressed air).

The combination valve should close and seal. Air should not be able to pass through the combination valve.

-- Operate the hand vacuum pump.

The combination valve should open. Air should be able to pass through the combination valve.

If combination valve does not open:

-- Replace the faulty combination valve. Refer to appropriate service information.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

  1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
  2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
  3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .