MAPP Sensor?

[thepitts]

Was just down at my local Scheid Diesel shop, talking about the IAT sensor. When Bret the tech says he has the Cummins Quick check and would I like him to plug it in and check it out. So I say ubet, he plugs it in and the IAT show fine but the MAPP sensor is showing 14lbs of boost at idel. This is with a boost module, we unplug the boost module and the same reading. So running down the road without the boost module it is showing 40lbs of boost on the quick check, gauge is 29 lbs. with the boost module gauge shows 32 lbs and Quick check shows 34. So my felling is the Mapp sensor is bad, to be showing 14 lbs of boost at idel. So what do you all think?

 

[BigCarl64]

The MAP sensor output was changed for the 2001 and up trucks. The MAP sensor will read 1 atm at idle, which is ~ 14. 7 psi. You would think Cummins would write the software to distinguish between the different year models.



There is a previous thread 'How to test MAP sensor?' that shows the exact MAP sensor voltages the 2001 trucks.



Hope this helps.

 

[ARARAR]

AIT SENSOR

? How do you test the voltage @ the AIT sensor? I have the 98. 5 24v. I have never had a boost problem: atleast I don't think so, even when after reading threads about loose sensors and inspected mine and found it was not even finger tight.

 

[thepitts]

BigCarl

There was also a code set that said MAPP sensor low voltage. I could just have them change it anyway and keep the old one for backup.