Codes 2973 and 2288 - Cummins ISX15 CM2250

Inspect all CAC hoses and boots for leaks, listen for any audible boost leaks while driving and pinpoint if you can hear any. Pay close attention to the charged intake hose elbow on the air compressor. If nothing is found, get the engine hot or with the fault active, engine off disconnect and check the resistance of the Turbo speed sensor in the VGT. Should be 600 to 1600 ohms. This is your two most common issues for this fault code(2973). If you replace the turbo speed sensor make sure to remove the old o-ring with the old sensor. If you shove the old o-ring into the turbo with the new sensor, you just bought yourself a new turbo.

Newer ISX15 I assume? Good Luck.....

 

I would check the speed sensor first if you hear no audible boost leaks or had good power when the faults were inactive before. The fix for the CAC will depend on where the leaks are coming from. You are not out much on checking the sensor if you have an accurate multimeter. The sensor is not terrible expensive either.

 

Yes, only wired sensor in the center section of the turbochager. Not part of the actuator at all. Sometimes it may be in the back side depending on the application. one 8mm screw holds it into the turbo. 12-18 inch lead with a 3 wire connector, only 2 wires are used. Google for photos.

 

Since the ECM is not getting a clear picture of true intake manifold pressure, the turbo is probably over boosting which is causing it to spin faster than normal and setting the speed code. I do not believe the speed sensor is faulty, it is a symptom of the intake pressure not reading right. I would say you have a wiring problem. Check for spread pins at the sensor connector, consider a new connector pigtail.

 

I think the when the sensor is unplugged, the ecm is ignoring the actual speed signal and going off of default values.