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Home >> Chevrolet >> 2003 >> Impala LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.8L >> Diagnostic Tests >> DTC P0418: Secondary Air Injection Relay Control Circuit >> Test Description
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Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

  1. 1

    The Diagnostic System Check - Engine Controls prompts you to complete some basic checks and store the Freeze Frame/Failure Records on the scan tool.
  2. 2

    Listen for a click when the relay operates. Command both the on and off states. Repeat the commands as necessary.
  3. 3

    This step tests for voltage at the feed.
  4. 4

    This step verifies that the control module is providing a ground.
  5. 5

    This step tests if ground is constantly being applied.
  6. 12

    The control module utilizes Electrically Erasable Programmable Read Only Memory (EEPROM). When the control module is replaced, the new control module must be programmed.