Output Diagnostic Test Mode (DTM)

OUTPUT TEST MODE (OTM)

Description

WARNING: Safety must be observed when using OTM:
- When all outputs are on, the electric fuel pump is briefly energized, make sure the fuel system is intact and is not being repaired at this time.
- When low speed or high speed fan control(s) are turned on, make sure the fan blades are clear of any obstruction.

Failure to follow these instructions may result in personal injury or death.

The OTM aids in diagnosing output actuators associated with the powertrain control module (PCM). This mode allows the technician to energize and de-energize most of the system output actuators on command. When entering OTM, the outputs can be turned off and on without activating the fan control. The low and high speed fan control(s) may be turned on separately without energizing the other outputs. This function is supported by the vehicle strategy but may not be present on all vehicles or available on all diagnostic tools.

As a safety precaution, the OTM defaults to the off state after 10 minutes and fuel pump off after approximately 7-10 seconds. The OTM also turns off after the vehicle is started or after cycling the key OFF then ON.