Communication Error (Normal and Abnormal PCM Responses)

PCM Responses:

It is possible to get a communication error from a scan tool when initiating a diagnostic test or accessing Parameter Identifications (PIDs). The communication error could be caused by operator error, the vehicle wiring, connectors, the Powertrain Control Module (PCM) or other control modules connected to the Data Link Connector (DLC) wiring, The PCM will respond to a scan tool whenever the tool requests a test. If manually entering the message strings using a generic scan tool, the numeric codes will be at the end of the string of characters. These are not diagnostic trouble codes. Listed are some of the numeric codes and generic descriptions that a scan tool may display when trying to perform some PCM operations. It is possible to get other numeric codes not listed. For a complete list of communication response codes, refer to Society of Automotive Engineers (SAE) document J219O enhanced E/E Diagnostic Test Modes. Some are normal responses to valid requests. The others are communication error responses. If the tool displays any of the communication error responses, refer to Pinpoint Test Step QA1, after checking scan tool connections, cable/adapters and entry of vehicle information. QA - Unable to Activate Self-Test/SCP Error/DTC Not Listed