Cummins ISB coughing - Code 42 and 275

[kidoo]

Hi, my engine is the Cummins ISB 300 HP, 2003. I have a CEL with code 42 and 275 and the engine is quickly coughing 5 times every 5 seconds. It does not do it all the time and normally not at highway speed. It would do it at idle or at any RPM and at  town type of speed.

Here is the sound of it:

http://s651.photobucket.com/user/Kidoo/media/P1090636_8092_zpse4866c19.mp4.html

I would also like to know where is the IAT on my engine.

Thanks

 

[Sean G.]

Sounds like the exhaust brake.  When the sound occurs, watch the exhaust brake linkage to see if it is moving. 

Not sure on the IAT sensor.  It would be between the turbo and engine though.  If there are two sensors in the intake then one would be it, the pressure sensor being the other.  With an engine serial I could lookup the service manual. 

 

[kidoo]

Ok, I will check the Jake brake, if I find it  :-\. My engine number is 57012456, it was made on november 2003, 300 HP ISB.

I found another connector over the engine, it is a 9 pin connector, I installed the scangauge on it and it gives me code ID641 FM05. I checked with Quickserve Cummins and it relate to 2383 Amber VGT Actuator Driver Circuit - Current Below Normal or Open Circuit.

I do not know why I have two connectors, one 6 pins under the dash and one 9 pin over the engine.

I had the question on another forums but the guys are more use to pick up engine. It seems to be a bit different engine but more people are talking about VGT, Jake brake, waste gate, so I will investigate into this.

I checked on Quickserve and I think I found the IAT over the intake cover. I took the exhaust sensor out and the line seemed to be pretty pack up. It screws on a pedestral kind of square tubing over the exhaust manifold, between the valve cover and the EGR, rear of engine.  I could not clean this tubing, I will check into this.

Thanks

 

[Sean G.]

Clean that passage for the exhaust pressure sensor.  That directly relates to VGT operation as the ECM watches exhaust pressure while operating the VGT.  The VGT is used for the exhaust break so the traditional butterfly exhaust brake will not be on this engine.  You will probably see the VGT actuator move when the sound occurs. 

The six pin connector is for late 90's to early 2000 vehicles with the J1708 CAN line.  The 9 pin has both J1708 and J1939 and is still used today.  The engine and trans probably talk on J1939 and does not go to the front of the coach.  The dash gauge info probably comes up on a J1708 CAN line from the engine.  This is a guess without coach schematics. 

 

[kidoo]

For the pressure sensor, do you mean the one the top of the engine, there is one over the EGR. As for the VGT moving, I do not see anything in there, the VGT mechanism is in a rectangular aluminum box and the motor is like screw on there. The is not bolt showing so I presume it is bolted from the inside. Aparantly this mechanism cannot be taken apart.

The motor on the VGT seems to be exactly like the one the EGR.

I now have a new code:
2349 Amber EGR Valve Control Circuit - Current Below Normal or Open Circuit

 

[Sean G.]

Yes, the exhaust gas pressure sensor should be in a small aluminum manifold that is attached to the exhaust manifold via a small tube. 

Sounds like you have the VGT with the electric actuator.  You are correct, there are no moving parts to see on that one.  Insite would need to be used to see VGT position. 

Clean that line out for the sensor then we can address the other codes.

 

[kidoo]

Yes, the exhaust gas pressure sensor should be in a small aluminum manifold that is attached to the exhaust manifold via a small tube. 

Sounds like you have the VGT with the electric actuator.  You are correct, there are no moving parts to see on that one.  Insite would need to be used to see VGT position. 

Clean that line out for the sensor then we can address the other codes.

Thanks, I will check that tube on the turbo. I saw one for the EGR and the tube was full of soot.