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 Maxxforce 7 fuel pressure sensor problem
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Ken_K
New Member

7 Posts

Posted - 03/07/2012 :  1:40:21 PM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
Hi all. The fuel pressure sensor is brand new but isn't registering psi. On servicemaxx pro it shows pressure as "error" in red. I'm new to servicemaxx pro and not 100% sure how to use it to it's full potential. I'm thinking there must be a short somewhere but don't know where to look. Any ideas?

Edited by - Ken_K on 03/07/2012 1:41:36 PM

Mechan1c
Top Member

USA
668 Posts

Posted - 03/07/2012 :  2:13:10 PM  Show Profile  Reply with Quote
Add some vehicle info like year make and model, any codes that you have.
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Ken_K
New Member

7 Posts

Posted - 03/07/2012 :  2:44:14 PM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
Year: 2007
Make: IH
Model: Integrated CE S Bus

DTC: 2372
SPN: 94
FMI: 1
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willism
Senior Member

United States
135 Posts

Posted - 03/08/2012 :  05:29:09 AM  Show Profile  Visit willism's Homepage  Reply with Quote
That code should keep the fuel filter light on on the dash is this so?
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Ken_K
New Member

7 Posts

Posted - 03/08/2012 :  06:18:15 AM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
Yes. When it comes on the engine loses power but when I clear the code it runs fine. It will throw the same code again in a few minutes after I clear it. When this bus first came in the shop it wouldn't hardly idle. The primer pump was leaking and was not serviceable so I replaced the whole housing. It ran better after that but still wasn't right. After I got a laptop and servicemaxx pro I tested the injectors and found that #1 was having some issues so I replaced it, which made it run even better but still not quite right. The only code it throws now is the low fuel pressure.

Edited by - Ken_K on 03/08/2012 06:20:02 AM
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willism
Senior Member

United States
135 Posts

Posted - 03/08/2012 :  06:43:44 AM  Show Profile  Visit willism's Homepage  Reply with Quote
Dont have any max7's but on the dt's ive had good luck replacing the fuel pressure regulator down in the filter bowl not sure where thats at on your bus I looked up on I know and told me this.

2372
Fuel pressure below normal

Dirty fuel filter
Fuel inlet restriction
Debris in fuel regulator
Failed fuel pump
Bias circuit/sensor

1. Using EST, open the D_ContinuousMonitor.ssn.

2. Verify sensor voltage is within Key-On Engine-Off (KOEO) specification. See "Performance Specifications" section of this manual.

3. Monitor sensor voltage. Verify an active Diagnostic Trouble Code (DTC) for the sensor.


If code is inactive, monitor the Parameter Identifier (PID) while wiggling the connector and all wires at suspected location. If the circuit is interrupted, the PID spikes and the DTC goes active.
If DTC is active, proceed to the next step.
4. Disconnect engine harness from sensor.
NOTE: Inspect connectors for damaged pins, corrosion, or loose pins. Repair if necessary.
5. Connect breakout harness to engine harness. Leave sensor disconnected.

Hope this helps

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Ken_K
New Member

7 Posts

Posted - 03/08/2012 :  1:29:42 PM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
May have found the issue. One of the rubber sleeves on the metal fuel lines was pretty much gone. How it wasn't leaking I don't know. I'm thinking it was sucking air and aerating the fuel. Parts will be in tomorrow, I'll post up when I get it back together.

willism: How did you find such useful information on bus ISIS? I can never seem to get a straight answer to anything I search for.
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Mechan1c
Top Member

USA
668 Posts

Posted - 03/08/2012 :  5:04:10 PM  Show Profile  Reply with Quote
Ken,
Go to IKNOW search, type in 2372 Maxxforce 7 and you will get IKNOW article #IK200375 with all the trouble codes; find your code and start at the top. All the info Will gave you and more is there. Give it a try and see if you find it...
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Ken_K
New Member

7 Posts

Posted - 03/09/2012 :  08:17:39 AM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
Well I feel like a complete idiot now. I searched for exactly what you said but it still made no since. All I saw was this:

2007 MaxxForce® 7 Engine Diagnostic Manual - Electronic Control Systems Diagnostics - Circuit Diagnostics - EFP Sensor (Engine Fuel Pressure) EFP Sensor (Engine Fuel Pressure) DTC SPN FMI Condition 1136 94 4 EFP signal out-of-range LOW 1137 94 3 EFP signal out-of-range HIGH 2371 94 0 Fuel pressure above normal 2372 94 1 Fuel pressure below normal Function diagram for the EFP sensor The EFP sensor function diagram includes the following: Engine Fuel Pressure (EFP) sensor Electronic Control Module (ECM) Warn Engine Lamp (WEL) Fuel filter lamp (amber) Function The EFP sensor provides a feedback signal to the ECM indicating engine fuel supply pressure. During engine operation, if pressure is low, the ECM turns on the amber FUEL lamp to alert the operator when the fuel filter needs servicing. Sensor Location The EFP sensor is installed in the secondary fuel filter housing on the top front of the engine. Tools Electronic Service Tool (EST) with MasterDiagnostic® software EZ-Tech® Interface Kit Digital Multimeter (DMM) 3-Banana Plug Harness 180-Pin Breakout Box Pressure Sensor Breakout Harness

After some research I found out if you select "compatibility view" in IE I see the same thing you listed. Doh!
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willism
Senior Member

United States
135 Posts

Posted - 03/09/2012 :  08:50:10 AM  Show Profile  Visit willism's Homepage  Reply with Quote
There's a lot of info on isis biggest issue is trying to find it if you don't use it a lot its a new exp every time :( Took me almost 2yrs for my IT department to get the right viewer so I could see the pictures on isis due to there security policy's....
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Ken_K
New Member

7 Posts

Posted - 03/09/2012 :  1:01:45 PM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
I've only had isis for two weeks and I've never done electronic diagnostics before. What really makes it tough is I have to learn on the fly and have multiple busses down right now. Got a VT365 that died on a route and won't start, a T444 with an injector out, another VT365 with a messed up turbo, a maxxforce 7 that needs the EGR cooler replaced, and an IC bus with a short that blows the ignition switch fuse at random. I'm also the only mechanic over a fleet of 30 busses so I have to tend to all the normal little stuff as well like oil changes, brake jobs, and fueling them up everyday.

Edited by - Ken_K on 03/09/2012 1:04:07 PM
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Mechan1c
Top Member

USA
668 Posts

Posted - 03/09/2012 :  4:16:07 PM  Show Profile  Reply with Quote
Don't feel bad, I went through the same viewing fiasco when we upgraded windows...The newest version of IE would not work with ISIS, but going back 1 version worked just fine.

Hang in there on the mechanic:bus ratio. It seems to be a sign of the times...I have 5:145 buses and another 100 vehicles and me. Juggling has become an art form.

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Ken_K
New Member

7 Posts

Posted - 03/23/2012 :  08:30:17 AM  Show Profile  Visit Ken_K's Homepage  Reply with Quote
Well it turns out that it was a combination of issues causing the low pressure problems. The primer pump was busted and sucking air, the rubber gromments on the metal fuel lines were in pretty bad shape and possibly sucking air, and the low pressure fuel pump pop off valve spring was missing. After fixing all of that it runs like a top now.
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TheRide
Active Member

46 Posts

Posted - 06/03/2014 :  9:11:58 PM  Show Profile  Visit TheRide's Homepage  Reply with Quote
I have a 2007 RE with the same 2372 code and there is no dash on. Fuel pressure reads between 40-80psi at idle.
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aaronwilmoth80911
Senior Member

83 Posts

Posted - 07/09/2014 :  05:34:05 AM  Show Profile  Visit aaronwilmoth80911's Homepage  Reply with Quote
We have one in right now that the fuel filter light came on and code 2372 came up. Changed the filter and it did no good. Now it will only run for about a minute or so and it seems as if it loses its prime and cannot continue on. Our buses do not have the electric fuel pump up top near the fuel filter, and I can't get the pictures to come up on ISIS, plus all the info I've found on ISIS only shows stuff for the electric fuel pump setup. Is there another location for the electric pump, or is there a manual pump somewhere that we are not seeing? Any help would be much appreciated. This is on a CE 2010 Maxxforce DT, not a 7.

Edited by - aaronwilmoth80911 on 07/09/2014 05:35:18 AM
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slippert
Advanced Member

USA
373 Posts

Posted - 07/09/2014 :  11:18:41 AM  Show Profile  Reply with Quote
2010 MF DT should have the mechanical pump mounted on the HP oil pump... also should have a primer pump on filter housing 1 and a half inch dia button on side of rock trap is primer... if it's electric setup... electric pump is in place of rock trap..
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aaronwilmoth80911
Senior Member

83 Posts

Posted - 07/09/2014 :  11:37:21 AM  Show Profile  Visit aaronwilmoth80911's Homepage  Reply with Quote
Figured out our buses are 2010 model year, built in 2009, with 2007 EPA standards. The 2007 standards still had the small screen in place of the electric pump, and the transfer pump mounted underneath the housing. Tech dealing with it just found the rubber grommets on the metal lines were split and in severely bad shape. Hopefully that's all it is.
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TheRide
Active Member

46 Posts

Posted - 07/16/2014 :  7:50:19 PM  Show Profile  Visit TheRide's Homepage  Reply with Quote
I had a fuel pressure issue last month with 2007 RE DT and found the manual lift pump bad, you could see it coming apart internally after I got it off and compared it to the new one. So far no fuel pressure issue.
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aaronwilmoth80911
Senior Member

83 Posts

Posted - 07/17/2014 :  05:20:44 AM  Show Profile  Visit aaronwilmoth80911's Homepage  Reply with Quote
We did figure out that it was a bad lift pump. We did however have the issue of the sleeves on the fuel line coming apart as well, so those were replaced also. Runs much better now.
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