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Doug Barnowski
Doug Barnowski,
Category: Medium and Heavy Trucks
Satisfied Customers: 7
Experience:  HD Truck Mechanic at VIP Truck Center, LLC
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I have an mp8 changed the egr cleaned the egr cooler and

Customer Question

i have an mp8 changed the egr cleaned the egr cooler and still have a pid 411 fmi 05,pid 503 fmi 04,pid 258 fmi 00, pid 506 fmi 04, pid 108 fmi 08
JA: What's the make/model/year of your truck? Engine type?
Customer: Mack pinnacle 2013 mp8
JA: Anything else you want the truck mechanic to know before I connect you?
Customer: ran the motor cleared codes and codes com back with out running the motor
Submitted: 9 months ago.
Category: Medium and Heavy Trucks
Expert:  Doug Barnowski replied 9 months ago.

Hi, my name is Doug.

I will need the MID numbers to those codes and which ones are active and inactive.

Customer: replied 9 months ago.
Ok I will have to plug back in I forgot to right them down
Expert:  Doug Barnowski replied 9 months ago.

I will also need the last six digits of the truck VIN.

Customer: replied 9 months ago.
Vin 012327 they are all mid128
Expert:  Doug Barnowski replied 9 months ago.

Does this engine have 1 or 2 EGR valves?

Customer: replied 9 months ago.
Expert:  Doug Barnowski replied 9 months ago.

OK, it looks like there is an "open" on the delta switch. Coming out of the EGR cooler is a rubber tube and it goes to an elbow & metal tube that is vertical, and then crossover to the intake mixer. So that vertical tube is called the Venturi tube, connected to the Venturi tube in the front is a EGR differential sensor. This sensor has had a big problem with the plug in harness wires rubbing thru at plug area or the 2 small holes in sensor become plugged. Your codes look like there is an electrical short and changing the sensor most of the time helps. Its a very common problem, with the short it will bring down any sensor on this circuit and set active codes. You can take it off and check harness going into sensor, you will have to remove the protective covering at connection point. Wires will make contact to sensor and start to rub thru then is over.

I hope this helps and please rate my service for you today.


Customer: replied 9 months ago.
I can not find any rubbing in the wires
Customer: replied 9 months ago.
I have the hole thing out and lum off. and would this sensor being the bad make the turbo louder than normal
Expert:  Doug Barnowski replied 9 months ago.

The rubbing would be wright when the wires come out of the sensor connector, it will look like a cut in the wire as the 3 wires are formed into one bunch.

That sensor scenes the difference between the turbo output and the EGR cooler output and the EECM takes that info and adjusts the turbos nozzle that affects the turbo speed.

Expert:  Doug Barnowski replied 9 months ago.

Also there is 2 holes in Venturi tube that might be plugged up. They must be clear also or replace the Venturi tube.

Customer: replied 9 months ago.
OK so I took the Venturi tube off everything looks clear air blows through easily I took another sensor off one of my other trucks and put it on still no difference
Customer: replied 9 months ago.
when it's running you can hear the turbo change and sometimes it's A lot louder and higher pitch than normal
Expert:  Doug Barnowski replied 9 months ago.

I'm having trouble finding some of these codes and I'm going to have to OPT OUT and let another Tech pick up where I'm leaving off.

Sorry for the inconvenience


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