Communication Error
It is possible to get a test fail error from a scan tool when initiating a test or viewing PIDs. The communication error could be caused by operator error, the vehicle wiring or connectors, or the powertrain control module (PCM) and other control modules connected to the DLC wiring. The PCM will respond to a scan tool whenever the scan tool requests a test. Some are normal responses to valid requests. The others are communication error responses. If the scan tool displays any of the test fail error responses re-initialize the scan tool. If the error is still present, GO to PINPOINT TEST AE: UNABLE TO ACTIVATE SELF TEST COMMUNICATION ERROR/DTC NOT LISTED , after checking scan tool connections, cable/adapters and entry of vehicle information. Verify auxiliary powertrain control (RPM control) is off when trying to perform self-tests.