Cummins ISX15 CM2250 (2010-12) Fault Code: 693 PID: 351 SPN: 1172 FMI: 2 Turbocharger 1 Compressor Intake Temperature- Data Erratic, Intermittent, or Incorrect

Circuit Description
The turbocharger compressor intake temperature sensor is a variable resistor sensor and is used to measure the temperature of the air entering the compressor intake of the turbocharger. The electronic control module (ECM) supplies 5-VDC to the compressor intake temperature signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the air temperature.

Component Location
Some engines use a combination compressor intake temperature/barometric pressure sensor located in the OEM intake air plumbing, rather than a turbocharger compressor intake temperature sensor. Refer to the engine wiring diagram to determine which sensor the engine is equipped with.

Conditions for Running the Diagnostics
This diagnostic consists of two parts:

The first part runs when the keyswitch is turned to the ON position after a 10 hour cold soak, during which the keyswitch has been turned OFF.
The second part runs continuously while the engine is running.
Conditions for Setting the Fault Codes
The ECM detects that the compressor intake temperature reading is too high or too low for the engine operating conditions.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
A default value for the compressor intake temperature reading is used.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute. If the fault code does not go inactive, it may be necessary to perform a 10 hour cold soak with the key OFF, then turn the keyswitch to the ON position so that the key ON portion of the diagnostic will run.
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For On Board Diagnostic (OBD) engines, the ECM will turn off the MIL after 3 consecutive trips where the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications

Shop Talk
Possible causes of this fault code include:

Stuck in-range compressor intake temperature sensor
High resistance in the compressor intake temperature sensor signal or return lines
ECM malfunction.

Possible Cause:
1) ECM failure
2) ECM calibration