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Ford LRG-425 efi diagnostics

NJSchrader

New Member
Joined
Dec 1, 2022
Messages
3
Location
Minnesota
Occupation
Ag
I'm helping a neighbor with his recently acquired JLG 450aj boom lift. It is a 2001 model with the ford LRG-425 efi engine. When key is turned to run, the electronic throttle body will cycle open/ shut rapidly, and when started the engine will run rough at a high idle and then shut off after 20 seconds or so.
The engine at some point has been updated from it's original ECM to the new style EPM with Bosch throttle body and O2 sensor, etc. The wiring harness has been checked over thoroughly. Temp, MAP, crank and cam position sensors, as well as throttle position sensor in the throttle body check out. We are leaning towards a fault in the EPM itself. When attempting to pull fault codes, we get 123, meaning no codes present

We would like to plug a laptop onto the diag connector, but have not been able to aquire the FPP Display software. I've read previous threads regarding this engine in other equipment, and would appreciate any insight.
A side note, the engine will start and idle perfectly when the installed throttle body is disconnected, and engine harness plugged into the spare TB.
 

Birken Vogt

Charter Member
Joined
Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
I only work on generators (at the moment), don't know EFI systems specifically, but I am a pretty good fighter of computers and have managed to interface the software to most everything I put my mind to except one, still working on it but it is not important.

Most of these spark ignition computer systems use the same or similar software.
 

excavator

Senior Member
Joined
Oct 16, 2006
Messages
1,445
Location
Pacific North West
I only work on generators (at the moment), don't know EFI systems specifically, but I am a pretty good fighter of computers and have managed to interface the software to most everything I put my mind to except one, still working on it but it is not important.

Most of these spark ignition computer systems use the same or similar software.
I fought one for a long while, crank no start. I bought the diagnostic cable ect but was unable to find any info as far as installation on a PC. Your info looks like what I needed, don't need it anymore but might just try it to see if I can make it work. Thanks.
 

Birken Vogt

Charter Member
Joined
Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
If you need any help just ask, if I come to any engine with this control system I attempt to connect to it now so I learn the software and can have it work for me when I really need it.
 

NJSchrader

New Member
Joined
Dec 1, 2022
Messages
3
Location
Minnesota
Occupation
Ag
Thanks for the download link. I had a chance to look through the instruction pdf, and have a grasp on how it works. What did you use as a dongle to connect to the machine? I'm assuming it communicates over CAN bus. I see there is the ECOM CANCapture device, but was thinking any USB to CAN device 'should' work, with the CAN high and CAN low connected appropriately.
 

NJSchrader

New Member
Joined
Dec 1, 2022
Messages
3
Location
Minnesota
Occupation
Ag
This is an update to our progress with the JLG 450AJ boom lift and Ford LRG-425. We acquired an ECOM usb cable and appropriate 4-pin adapter harness to connect to the diag connector. While running, we had DTC's 311, 313, 315, and 321 as active faults. All being "Injector open or short to ground" for a given cylinder. We also had DTC 412, which is "spark coil 1 primary shorted". After following the flowcharts for each DTC, and not finding any faults in wiring, injectors, or the coil assembly, we have determined our problem lies in the EPM itself.

Is anyone aware of a reputable shop that is able to work on and repair these E-controls EPM's? Thanks
 

Birken Vogt

Charter Member
Joined
Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
erdltdinc.com was suggested to me as somebody who could repair these.

Confirm you really do have those injectors and coil present in your application? I have several units that log a continuous fault code when running of starter solenoid ckt open/gas valve ckt open because they are simply not connected, they are controlled another way.
 
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