ISB Fault Code 2359

motofamily · 10-12-2011, 09:00 PM

Okay so after several months of saving and fighting with extended warranty companies we finally replaced our turbo as the vgt in it was messed up well make a long story short we picked the rv up today and now it has another check engine light with a fault code of 2359 and they were nice enough to plug it in and tell me that it is the EGR Differential Pressure Sensor they say I can remove the sensor and clean the carbon out of the orfaces and then reinstal see if it goes away if not then replace sensor. Any help would be great cummins wanted $100 to plug it in tomorrow morning and see if they could figure it out. I am tired of throwing money at this I don't mind getting my hands dirty just need to know for sure what to do.

2006 cummins ISB 300

dieselbeaver · 10-13-2011, 09:04 PM

Hey there,

Per your code this is a list of possible causes. 1-Damaged EGR pressure sensor. 2-Stuck open EGR valve. 3- EGR pressure sensor ports clogged. Also per Cummins troubleshooting you are to check and see if the ECM is flashed with the latest revision. I have seen sensors fail, valves fail (out right and with debris holding open), and I have seen the ports plugged with carbon.

Since you don't mention any other faults relating to the valve itself, I am inclined to look at the ports being plugged. Since I don't have an engine serial number I can't check for any different info by the actual ECM model.

Look on the intake side of the engine (opposite of the turbo) now look for a device with a 3 wire harness going to it and I believe a 2 bolt bracket holding it down. The bracket covers about 1/2 the sensor and it bolts to the other end from the harness connection. Unbolt it and carefully remove it. Look at the bottom of the sensor for cacked on carbon and look where it bolts to the manifold for the 2 holes that feed it the exhaust gases. They need to be free and open. There may be 2 plugs that grant you access to the cross drillings into the gas stream. If plugged you need to be very careful not to scratch off the GREEN colored coating that is applied to resist carbon build up. ( actually a joke or we wouldn't have a plugging issue). Per cummins you can only clean with a wooden stick (skewer?) or pipe cleaners. I think a little bit of carb cleaner may help but it's not sanctioned by cummins. There are 2 plugs to remove that also uncover the remainder of the passages. Cummins does offer the intake piece for sale and if I recall it wasn't as bad as I thought it would be (because it's a common issue I think).

Try that, but I do have to caution there is a reason they charge $100 to check codes.... It's called a $3000 software/hardware suite just to do so. And with that you have the access to all the tests you really need to do to t/s most electronic issues. Per the t/s on this code alone you are testing the EGR valve and pin testing the sensor garness and looking at live engine data to check operation. A leaking water pump is easy to diagnose as no electrons are in the equation. But electronic diagnosis via changing parts or guessing is iffy at best.

Good luck, if you get me some more info I will check a little deeper. But not till Monday night - sorry, gotta take the family to the coast.

motofamily · 10-13-2011, 09:38 PM

I know why they charge $100 an hour my thing was they had just worked on it for a cel and there is no way they test drove it and the cel didnt come on because I didnt even move it 200 feet and it was on. Thanks for the help they actually did plug it in thats how they gave me the code they said to do the same thing you said to do and that I could drive it but it did need to be cleaned or replace the sensor. Gonna be purchasing vmspc next week tired of messing around seems like the only way to go. Thanks and have a good trip we are gonna try to clean the ports on the thang and head out on a close trip been a year since we have used our rv.....