Reading and Clearing Diagnostic Trouble Codes

Use Rotunda New Generation Star (NGS) Tester, connected to the data link connector, to retrieve Diagnostic Trouble Codes (DTCs) and to execute self test diagnostics for the GEM. If DTCs are found, refer to Diagnostic Trouble Code Guide to continue diagnostics. Diagnostic Trouble Code DescriptionsIf no DTCs are found, or if the GEM cannot be accessed by NGS tester, perform appropriate pinpoint tests. Pinpoint Tests