Special Test Modes

The Diagnostic Test Mode (DTM) aids in repairing output actuators associated with the powertrain control module. It allows the technician to energize and de-energize most of the system output actuators on command.

PERFORMING DIAGNOSTIC TEST MODE (DTM)

NOTE: You must enter Diagnostic Test Mode (DTM) with ignition switch in RUN and the engine off.

- Perform visual inspection and vehicle preparation as required.
- Select "Vehicle and Engine Selection" menu.
- Select year, engine, and model with the appropriate qualifier, if needed; for example, 49-State/California.
- Select "Diagnostic Data Link" menu.
- Select "Diagnostic Test Mode" menu.
- Enter "Active Tests."
- Enter "Output Control."
- Follow operating instructions from the New Generation Star (NGS) menu screen.