How to Troubleshoot Fuel and Emissions Systems
How to End a Troubleshooting Session (required after any troubleshooting)
  1. Reset the ECM with the HDS.
  1. Turn the ignition switch OFF.
  1. Disconnect the HDS from the DLC.
    NOTE: The ECM is part of the immobilizer system. If you replace the ECM, it will have a different immobilizer code. In order for the engine to start, you must rewrite the immobilizer code with the HDS.