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+--- Thread: isx12 cm2250 fuel pressure only builds if injector harness is disconnected (/showthread.php?tid=6833)
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 12-31-2020
(12-31-2020 )num1enloe Wrote: insite doesn t show any faults but i connected with calterm and it shows fault 272
has the fuel pump actuator been replaced?-- is it plugged in?. --corrosion on the pins?
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 12-31-2020
yep actuator been changed. pins check out fine. im pulling the call at the moment for ya.
ive ohmed out almost every wire on the engine harness and the oem harness.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 01-01-2021
Just my own thoughts on it so far ... just taking some guesses and speculating ...
Having +5v all the time on the injector harness means nothing whatsoever to me. For all anyone knows, the ecm may be using the ground circuit to fire the injector, or perhaps a high voltage like on the ISX engines (ref: http://rawze.com/forums/showthread.php?tid=737&pid=9973#pid9973 ) ... and the +5v on it at all times might be normal. Even in the o-scope pic I took in the references post, you can see that there is about +5v on the injector between pulse cycles when it is not firing.
Does it actually have low fuel pressure during cranking?... Quickserv should tell you what the minimum allowed is in the troubleshooting tree. Is the fuel pressure actually below this point?... and if so, what is the ecm reporting and what does Quickserv say is the minimum for that engine ser#??
Also, if the injectors were actually being held wide open in a constant state by the ecm .... as soon as you cranked it, the engine would go into runaway. - I think you might be barking up the wrong tree, just saying.
(If fuel pressure is lower than what Quickserv says it is supposed to be minimum )...
Sounds to me like your fuel pump itself may have a snapped/sheered shaft, or some normally pressurized circuit, check-valve, the fuel actuator, etc.. is not letting it build proper pressure while it is trying to fire off.
- You also mentioned you have an active code for the fuel pressure actuator.... you need to solve that while your at it.
You said you flashed it back to factory programming ... I can only assume you installed the right one according to Quickserv and the engine ser# ... With the correct factory program installed, is there any alarms for engine shutdown? ... Is it stuck in an Anti-theft state? .... What is the fuel pressure during cranking? ... does it crank over slower than normal? .. Any restrictions in the air or fuel system?... Collapsed filter? etc.?
You said it had a delete done to it ... Anyone remove the down pipe off the back of the turbo to see if the exhaust has internally collapsed because some moron did not hollow out the cans correctly? ... Anyone check the turbo to see if it is locked up at 100% closed? .. blocked up exhaust or intake can cause one not to run more than a few moments at a time too.
Anyone pressurize the fuel tanks to 10 PSI, checked for leaks, and verified the systen was not sucking air anywhere?
A lot of things can cause an engine not to run. It is anyone's guess when they are not standing right there in front of it looking at it.
Quickserv is your friend. It has all the fuel system diagrams, no-start procedures and checks.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Signature620 - 01-01-2021
Have a read of the fault information for FC272. It reads a lot like this thread.
Code
Fault Code: 272
PID(P): S126
SPN: 1347
FMI: 3/3
Lamp: Amber
Reason:
High signal voltage or open circuit is detected at the fuel pump actuator circuit.
Effect:
Engine may run rough, may stop running, may not start, or may be difficult to start.
You have an open circuit or short circuit in the fuel pump actuator or its wiring.
The ECM disables the fuel pump actuator driver as soon as it detects this fault so you'll need to let the ECM power down each time you want to recheck if it's still active.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 01-02-2021
I am looking at the file you sent me.
It has active error codes for...
2374 - Low signal voltage detected at the exhaust gas pressure circuit. - (likely unplugged)
322 - Malfunction detected at injector 1 circuit. (bad/shorted out injector detected).
Neither of these two faults should be in the ecm at all... deleted programming or not. These Issues need to be solved and these 2 codes are not normal for even a deleted truck. The ECM is detecting something wrong with Injector #1. It is also complaining that the Exhaust Gas (Exhaust manifold pressure sensor) is unplugged or shorted out to ground.
- The exhaust gas pressure sensor is a critical sensor that helps control proper fuel-air-mix, proper cylinder pressures, and protected the engine, even if the engine has a delete on it. There is no reason whatsoever EVER to disable this sensor during delete programming ... not even if you are making some serious big HP mods .... It SHOULD NEVER BE DISABLED OR DEFEATED AND ONLY A BAD DELETE OR SOME COMPLETE MORON WHO HAS NO CLUE WHATSOEVER HOW THESE ENGINES RUN WOULD RECOMMEND OR ATTEMPT TO DISABLE IT AS SUCH!. - I can only assume it is unplugged due to some horrible delete programming that has been in that engine at some previous point. That or there is a wiring issue or the sensor is bad.
You should also check the feed line/circuit to the sensor as well when hooking it back up/replacing the sensor. The line feeding them off the manifold and thru the thermostat housing likes to clog up and give incorrect readings, never throwing any faults, but can cause all sorts of engine efficiency issues. Some bad delete shops will also unhook this feed-line out of sheer stupidity too.
========================
There are also a bunch of active emissions-related faults too. Here they are (basically) ...
3597 - DEF Controller Harness - (unplugged)
2771 - Engine Outlet NOx Sensor - (unplugged)
3314 - DOC Inlet Temp Sensor - (unplugged)
3317 - DPF Inlet Temp Sensor (unplugged)
3319 - DPF Outlet Temp Sensor - (unplugged)
1881 - DPF Delta-P sensor - (unplugged)
3134 - DPF Outlet Pressure Sensor - (unplugged)
3142 - SCR Inlet Temp Sensor - (unplugged)
3146 - SCR Outlet Temp Sensor - (unplugged)
- I can only assume that the entire harness for those systems has been disconnected. If so, then someone need to check Can-Buss #2 J1939 circuit and see if it is at 60 ohms because the engine harness does NOT contain the second terminating resistor on CAN2 ... but instead, it is located at the SCR controller. This means if someone unplugs the entire harness, then the terminating resistor is going to be missing. - The engine will still likely run, but can have some J1939 instability issues.
The terminating resistor on one end is located inside the Turbo Actuator. The other end is usually at the DEF controller or in the wire harness just past the main harness for it. The way I check the 2 terminating resistors is that I unplug the Turbo actuator harness and ohm out the (green and yellow wires) J1939 wires on the turbo actuator cable itself (not the engine side) to ensure it has its a proper 120-ohm terminating resistor internal to it. I then will ohm out the engine side of that connector to see if the green/yellow pair have 120-ohms on them as well (engine off and truck turned off). With 120-ohms on both sides of the plugs, connecting them back together makes for the proper 60-ohms. It can also be checked for 60-ohms at the "can2 weather-pack" engine harness connector on the drivers side when everything is plugged in properly.
- If either is missing, everything will run and likely not complain, but then there will be electrical noise and other gremlin issues.
That is my main concern after seeing all those aftertreatment related codes, as a lot of shops will unplug those harnesses and have no regard to the J1939 whatsoever ... and then the truck owner is always chasing ghosts, or the Turbo Actuator circuit board burns up every so often. This is because the one remaining resistor in the actuator attracts all the electrical and alternator noise and causes the board to go bad or loose its memory every so often due to it absorbing too much noise, etc. That or other ghost failures on the system, that seem to happen or come and go. I have seen a lot of trucks with this type of problems when someone unplugs entire SCR harnesses and does not install a terminating resistor at the end that was unplugged.
As far as the program you sent me... here is what else I see in it at a glance (looks like it was flashed back to stock programming recently) ...
- The program has an internal data log of the fuel pump actuator being faulty but but no actual active error code was being reported yet in the program you sent me yet. Just mentioning it, as you said it had related faults at one point earlier in the thread here.
- Aftertreaement system counter is counting up towards it, but it is not requesting an engine shutdown yet.
- Aftertreaement DPF missing system counter is counting up towards it, but it is not requesting an engine shutdown yet either.
- Aftertreaement Excessive soot Load system counter is counting up towards it, but it is not requesting an engine shutdown yet either.
- Urea Tank Level is reporting a -7 (negative 7) for its tank level. This is in error, likely the sensor is unplugged. No derates or shutdowns requested for it yet either that I can see.
- The Soot filter manager is sending requests to the main Aftertreatment manager for a regen to be performed due to not being able to read the DPF Delta-P sensor. The Aftertreatment mgr however is not requesting a parked regen yet though (most likely due to the other errors).
- Although not currently active, there are some records for Crank Case pressure darates being active on multiple occasions in the past. If the engine has had a delete program in it then the Crank case filter should have been drilled out or a maint. free one installed. - Having excess crank case pressure because someone is not changing filter often enough can and will cause turbo issues and failures as well as overhead cam/roller failures due to reduced oil pressure differential in the overhead valve train. This is clearly pointing towards an abused engine.
- There are also records for low oil pressure derates and oil pressure shutdowns in the engines past. This is not a common thing to see. This is clearly pointing to an abused engine.
- There are artifacts of delete programming that has been in the ecm at one point. - Backing up and restoring the the "features and parameters" in Inside when the engine was flashed back to stock programming did this. - i have seen this before plenty of times ... it is harmless, only a few odd control settings. Just thought that I would mention it, as I noticed it.
- The ecm is reporting that someone has performed an OBD2 fault-erase procedure on it. Likely some third-party software was used to clear faults. it is harmless, just thought i would mention it, as it is being reported in the program you sent me.
- DEF system is reporting dilluted DEF detected (likely from the harness being unplugged). Not causing a shutdown or derate at this time though.
- Urea injection manager is reporting errors but has not thrown codes for it yet. Likely due to harness unplugged.
- Urea manager reports that the DEF pump was trying to run during the ecm was last shut down.
===========
This is obviously not any sort of delete programming. It looks like someone flashed the ecm back to stock programming and that there is nothing indicating that the ecm is refusing to run the engine. - At least that is what it is showing me at a glance.
The engine, although should be showing several faults in the dash, should run and idle the engine according to what i see in the program. It should be stated though that the ecm program itself only contains a limited view of what is actually going on.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - DVT873 - 01-02-2021
Will c^lt&rm run on Windows 7 32 bit?
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - Rawze - 01-02-2021
(01-02-2021 )DVT873 Wrote: Will c^lt&rm run on Windows 7 32 bit?
I have seen people running it on win7, win8 both 32 bit and 64-bit. i have seen ppl running it plenty of times on win10 as well.
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 01-02-2021
yeah that was not a good time to pul the cal from calterm. all them codes are cause of things being disconnected the for testing harness. the exhaust pressure sensors along with everything on the hot side of the engine was disconnected and flopped over to the fuel pump side for testing and also to pull valve cover off to inspect the internal injector harness and the oil pressure codes were from when i pulled the sensor and installed manual gauge. but even with the crappy stuff i sent you. i believe ya got me in the right direction. i got so caught up on the fact the fuel pressure would build higher with the harness disconnected. that i put my blinders on and chased electrical. the fuel pressure was still only half of what was being demanded. i knew i was missing something obvious!!! im going to have to nominate myself for the ID10T award.
if i were to do this programming myself (instead of joe shmo from http://www.hismomsbasement.-com lol if that's an actual website ima laugh) would you be willing to take a look at it? and let me know if i suck or am on the right track? or if you could point me in the right direction of a guide to follow?
RE: isx12 cm2250 fuel pressure only builds if injector harness is disconnected - num1enloe - 01-02-2021
this truck was originally an oil field truck but not the drive it like ya stole it oil field truck. it was a pump truck that sat in the same spot most of its life. low miles high hours. remote start most of the time so one can assume the only pre inspection ever done was most likely pre-delivery