Reading and Clearing Diagnostic Trouble Codes

Use a bi-directional scan tool to check for any IPC trouble Codes. If IPC Diagnostics cannot be entered, attempt communication with the ECM.

^ If neither respond, check the Serial Data Line for and open or short to ground.

^ If one or both respond, check power and ground connections to the IPC and the Serial Data Line to the IPC. If all are OK, the diagnostic capabilities of the IPC are not available.