Theory Of Operation

The Ambient Temperature Sensor signal is a direct input to the Totally Integrated Power Module (TIPM). The TIPM sends the Powertrain Control Module (PCM) the ambient temperature signal over the CAN C bus.

When Monitored: 

This diagnostic runs continuously when the following conditions are met:

• With the ignition on
• Battery voltage between 9.0 and 16.0 volts

Set Conditions: 

• The Powertrain Control Module (PCM) either doesn't receive a bus message or receives an implausible bus message from the TIPM.

Default Actions: 

• The MIL light will illuminate.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.  Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .