Boost code

[FirstMack]

I have a 2004 Mack ch613 has an AC 427 engine noticed a little Miss in the truck yesterday when I got home I had the lightning bolt code did the flash test come up with code number 22 which says boost pressure just wondering what to do and where to go to track this problem down I am new to the big truck world

[Joey Mack]

The sensor is in the top of the intake near the inlet, do you have a boost gauge? I have one piece of info that is important... If it turns out that you are replacing the boost sensor... Make sure it is the EXACT one for that engine. The part number is stamped into one of the flats on the sensor. 24MT--- i think, a little rusty here. Make sure the part is the correct one. They run on a 5 volt reference, but the turbo commands are as low as 1/4 volt differentials.  The wrong sensor will piss you off.  It will pull good then open the waste gate too early and the truck will lay down...

[FirstMack]

That sounds exactly like what it's doing it's like it's opening too early I don't have a boost gauge but I can put one on. When the truck is pulling hard at almost feels like a Miss in the truck 

 

[Joey Mack]

Was the sensor replaced recently? Is it the original engine?

[FirstMack]

Had in frame about 25000 miles ago done by Mack dealership. Sensor has not been replaced. 

[Joey Mack]

Ok.. Of course im miles away, so I don't want to make this bigger then it is. What are you using for diagnostics, laptop for example.?

[FirstMack]

No lightning bolt flash code. Code 22. Where you push cruise control decel switch and lightning bolt flashes and you count flashes. The picture of sensor is in the intake 

[Joey Mack]

Not good. Water gets in.  Have you tested the sensor with a DVOM?

[FirstMack]

No is that the sensor you talking about or another one

 

[Joey Mack]

The other sensor is the one.  I think that one is IAT. Intake air temp... 

[fjh]

18 hours ago, Joey Mack said:

The other sensor is the one.  I think that one is IAT. Intake air temp... 

humidity sensor! when these engine hit 33 psi boost they derate! I often thought of putting  a pressure regulator on the boost sensor so the putor would never see the max but never had the opportunity!😪