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 Post subject: Fleet o' Jeeps, software questions
PostPosted: Thu Aug 04, 2022 6:30 pm 
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Greetings!

I'm a mechanic with the (dubious?) honor of being in charge of maintaining a small fleet of diesel cars and light trucks, mostly old Mercedes, plus five KJ CRD, all of them 4wd automatics with EGR physically deleted but not coded out:
1. Black 05 Limited. Recently replaced rockers, lifters, fuel pumps. Won't start.
2. Grey/brown 06 Limited. Recently resurrected with a rebuilt engine, trans, new turbo, and a bunch else. Runs and drives but needs injectors learned.
3. Blue 06 Limited. Got a new turbo a year ago, recently diagnosed to have bad rockers/lifters.
4. Silver 06 Renegade. Got a new turbo two years ago, runs and drives well.
5. Tan 05 Sport. Engine disassembled, this is a parts donor.

Plus a spare engine sitting on a stand.

Having learned on BMWs and other Germans, I find working on these mechanically difficult but within expectations for a European vehicle (the engine, anyway). Where I have trouble is with software; my scan tools, primarily ScanMaster on a laptop with an ELM327 cable, will talk to the ECM and TCM but with limited functionality. I can read codes and most data, but transmission temperature, transmission learning, and injector codes are three notable things I've been unable to do and had to outsource to the two "local" dealers, each about an hour away.

At the moment, my biggest problem is the black one, which despite a lot of work won't start, throwing P0091 and P2295 codes. Walking through the FSM's diagnostics, the ECM correctly threw a P0090 code when the fuel quantity solenoid was unplugged, but failed to throw a P0092 when the plug was shorted, leading to the conclusion that the ECM is bad. I understand the ECM has to be coded to the SKIM and TCM or it won't run more than three seconds. Three questions about this:
1. Is there any risk of damaging something if I swap in another ECM to see if it fires?
2. The parts donor is complete and was running when the engine overheated and was disassembled. Can I swap its ECM, SKIM, TCM, and injectors into the black one as a matched set, or is there more that needs to match?
3. Does anyone know of any PC software that can program the ECM for VIN and injector codes using ELM327? Otherwise, what kind of hardware do I need to be able to work with the vehicle's software without having to schlep it to the dealer?


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Thu Aug 04, 2022 11:11 pm 
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Always the obvious first question as always, are you darn sure you have the belt/valve timing correct?
All sensors properly connected? No chafed or bare wires anywhere?

Only high end bi-directional scanners like the Snap On Varus, ThinkBook Pro, Mopar DRBIII, and a few others are capable of programing the ECM with the VIN, SKIM, Injector Coles, etc... I don't know of any laptop programs using a dongle or MPPS type cable that will perform bi-directional programing much less even read all the data in the ECM, BCM, or TCM.

As to the TCM, it has no security paring to the vehicle, any TCM for the Jeep Liberty diesel will plug and play. Many TCM's used in gas model Jeeps and Dodge with the 545RFE transmission will actually plug & play in the Jeep Liberty, but you must be very careful of potential engine overrevving beyond redline due to their gas engine programing.
Some have installed TCM's from Dodge or Jeep trucks but you have to be real careful as TCM's out of gas powered vehicles have much higher shift points values vs diesel powered vehicles and can allow the engine's RPMs to rev way beyond its red line when downshifting at higher speeds.

As to your codes:
Both these codes point to low voltage problems. Start with battery voltage.
P0091 -- Fuel Quantity (metering) solenoid – short to ground Wiring short to ground, Fuel Quantity (metering) solenoid, ECM
It is located on the back of the CP3 injection pump and is available to order online and can be changed out.
But the code says short to ground, so I would check all wiring and connectors very closely as ECM going bad is a very rarely reported occurrence. You should rule out all other possibilities before saying it is a bad ECM. Lots of testing can be done on the wiring between the Fuel Quantity solenoid and the pins in the ECM connector.
Check Supply Voltage @ Sensor, it should be 12v
Quote:
The Fuel Control Actuator solenoid valve is a pulse-width modulated valve that controls the amount of fuel sent or delayed to the high-pressure pump elements inside the high-pressure pump. Mopar PN: 5159962AA // Bosch PN: 0928400822

P2295 -- Fuel Pressure Regulator 2 Control Circuit Low
When a code P2295 is stored, it means that the control module (ECM) has detected a low reference voltage signal from the control circuit of the electronic fuel pressure regulator designated 2. The numeral designation 1 is used in systems which have multiple electronic fuel pressure regulators.

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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Fri Aug 05, 2022 1:18 am 
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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Fri Aug 05, 2022 3:01 am 
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WWDiesel wrote:
Always the obvious first question as always, are you darn sure you have the belt/valve timing correct?


I'd say so. It was done with factory tools and turned over by hand two full rotations before the starter got involved. I've done at least two t-belt jobs on these motors and more than I can count on others.

Quote:
All sensors properly connected? No chafed or bare wires anywhere?


Looked over the wiring pretty carefully, checked and rechecked connectors, made some generous donations to my swear jar over Jeep/VM choosing to use physically interchangeable wiring plugs in proximity to each other...

Quote:
Both these codes point to low voltage problems. Start with battery voltage.


When the battery was charged some (from 12.3 to 12.6+), all codes went away and cranking speed felt adequate, but doesn't the failure to throw a P0092 when the plug is shorted mean a bad ECM? The FSM's pretty clear it does, though the FSM has numerous errors elsewhere.

Quote:
P0091 -- Fuel Quantity (metering) solenoid – short to ground Wiring short to ground, Fuel Quantity (metering) solenoid, ECM


Hm? I gathered this one is for low voltage, not a short to ground.

Quote:
It is located on the back of the CP3 injection pump and is available to order online and can be changed out.


98% sure a new one came with the new high-pressure pump (an underling installed it), which came from the dealer.

Quote:
But the code says short to ground, so I would check all wiring and connectors very closely as ECM going bad is a very rarely reported occurrence. You should rule out all other possibilities before saying it is a bad ECM. Lots of testing can be done on the wiring between the Fuel Quantity solenoid and the pins in the ECM connector.
Check Supply Voltage @ Sensor, it should be 12v


It's 4.9ish volts when the battery is >12.0. Both wires test <1 ohm between the ECM plug and the solenoid. My notes are unclear, but if memory serves I also read the same 4.9V at the ECM.

The most expedient diagnostic at this point would be to take the parts car's ECM and try it in the black car. If it runs for only three seconds, that'll be enough information. The question is: is anything at risk from trying this?


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Fri Aug 05, 2022 2:07 pm 
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Looks like you have covered all the main bases. :D
Yes, you could install an ECM from another Jeep diesel for the 3 minute test. No damage will incur.

From some of my notes:
The Fuel Pressure Sensor, mounted very near middle of the rail, with 3 wire connector is the Eyes and Ears of the ECM, and continuously sending data to the ECM, which monitors and uses this data to send PWM voltage orders to the Fuel Quantity Solenoid (CP3), and the Fuel Pressure Solenoid (rear of Common Rail) to manage how much fuel enters the fuel rail, and how much fuel is bled out the back end of the fuel rail, to accomplish what hydraulic pressure the ECM wants at that exact particular instant. Any deviation (beyond normal parameters) from what the ECM expects to "see" results in Diagnostic Trouble Code set, and Limp Home Mode. Any goop or burr or something that causes the solenoid valves to stick, even for a millisecond, will also result in the same situation. If the communication between the ECM and Fuel Pressure Sensor is interrupted or erratic, It seems to slip into a "panic mode" where timing and quantity result in enormous clouds of black smoke even at moderate rpm.

The Fuel Quantity Solenoid on the CP3 functions essentially like a flow valve on a hose, and through PWM voltage from ECM, regulates flow to the HP pistons. Voltage increase closes flow. Voltage decrease increases flow to wide open maximum. Any voltage interruption in this control circuit is "fail-safe", as in the engine goes into Limp Home Mode, but can continue to run, but badly. All pressure regulation duties are now up to the Fuel Pressure Solenoid, who attempts to regulate through bleed-off.

The Fuel Pressure Solenoid on the Fuel Rail functions essentially to bleed off precise excess fuel, to establish the maximum fuel pressure in the rail. PWM Voltage from the ECM regulates, as voltage increases, rail pressure increases. When voltage decreases, rail pressure ceiling decreases. Any voltage interruption in this control circuit results in instant die, and no start condition, as there is no bleed-off pressure safety to keep pressures from spiking and damaging rail or injectors.
My bet is a problem with the wiring or connectors. Somewhere, one (or more) of these 3 has a communication problem.

From another member: "Check the fuel rail solenoid pins at the ECU. You may find one of them discolored. Scrub it and put dielectric on it and give it a minute, like 1 degree bend for better contact. I've fixed 2 CRD's this way"

Very good reading on fuel pressure control:> https://www.dropbox.com/s/n3lrg9i50vbwo ... l.pdf?dl=0

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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 06, 2022 7:56 am 
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I'm getting conflicting information regarding whether P0091 is a short to ground or a low voltage condition. The FSM does refer to it as a short, but most online info says it's a low signal.

I cleaned and slightly bent the contacts on both the original ECM and the parts car's. For a minute, the spare one wouldn't talk to my scanner (BUS INIT error) but later cleared up. There is no other apparent difference in the behavior of the two ECMs.

The ~800CCA battery is charged to 12.6ish standing alone or installed with the ignition off, 12.4 with ignition on according to my multimeter, 12.2 according to my scanner.

Turning on the ignition, there begins a slow pulse of something turning on and off, and a faster clicking sound from somewhere near the fuel filter housing. After a few seconds, the pulsation increases in frequency to about 3Hz, with no change to the clicking. Voltage to the fuel quantity solenoid (FQS) hovers mostly around 6-8V, as low as 4.something and as high as 9.5. I don't have an oscilloscope, but the pulsation appears to time with voltage fluctuation.

Once or twice, wiggling the fuel pressure solenoid (FPS) plug changed the later faster pulsation to a whine, but now I can't replicate it. Unplugging the FPS stops the later 3Hz pulsation, but neither the slower initial one, nor the clicking, and now FQS voltage fluctuates between 10.9 and 11.9 with occasional dips as low as 9.4V. The FPS unplugged adds codes P2294, P1140, P1250, and P0403. The latter three are not present with the FPS connected, though the vacuum and boost solenoids are unplugged this whole time, as is the EGR valve.

At no point do the following things happen no matter what I do: P0092; the ECM deem the FQS signal high enough not to throw P0091; the engine come close to firing, though it turns over just fine.

The link doesn't work, just takes me to the Autonerdz homepage.


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 06, 2022 11:21 am 
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Having done more testing, I have to correct, or at least update, some of the data points previously written. The only time I get no codes is when I've reset the ECM without reconnecting the scanner - false negative there. Fourish volts happen when the glowplugs cycle, and otherwise the FQS is getting at least 6, though apparently even 11.9 isn't enough.

More importantly, while the wiring physically looks fine, checking the power and ground circuits for the ECM revealed that two out of three power supply pins at C2 appear to be broken inside the engine wiring harness, somewhere between C2 by the brake booster and C117 and C105 by the coolant tank. Back problems are forcing me to take a break from cutting open the wiring harness to find the break; I'm tempted to simply run two or three new wires instead, on a much shorter and more logical path straight to the front power distribution box, rather than all the way across the enginebay and back again.


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 06, 2022 2:08 pm 
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moroza wrote:
The link doesn't work, just takes me to the Autonerdz homepage.

Direct link through LOSTJeeps to original file on Web would not work for whatever reason??? :banghead: It keep redirecting. http://www.autonerdz.com/yabbfiles/Attachments/CRD.pdf
Have no idea why it was doing this, if you copy link and paste it in browser, it works, but if you click on the same link in LOST post, it redirects, very frustrating!!! :furious:

Had to load file to DropBox and share to get the link to work properly.> Fuel Pressure Regulator and Fuel Quantity Solenoid Control
Let me know if you can't view it.

Good Reading! Save this file for future reference as it has a lot of good information contained within it. :wink:

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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Wed Aug 10, 2022 4:31 pm 
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Thanks, I got it to work and saved to my laptop for future reference.

I took apart the engine wiring harness, found numerous wires stiff and stuck together, indicating long-term overheating due to some combination of insufficient gauges, insufficient temperature rating of the insulation, and poor placement right over the turbo. All of those are easily avoidable engineering/design flaws that can result in tricky and expensive problems, not the least of which is a fire. One of the wires was completely severed, and it happened to be the Brown/Pink that feeds two of three power supply pins at the ECM. It inexplicably begins as a single 14ga before splitting to two 10ga that then feed the ECU (and a couple of smaller consumers). I replaced that wire from the grey plug on starboard (took apart the plug and reused the pin terminal) all the way to the splice, with a length of 10ga, then wrapped the wiring harness with alu foil before reinstalling. Problem solved. I'm disappointed by the engineering of this particular part of the vehicle.

Runs and drives and now has two lesser problems:

1. Overheating on prolonged hillclimbs. Bleeder screw/petcock thing on the radiator doesn't appear to do anything at any time.
2. Fuel losing its prime after sitting a couple of hours.

Now off to do my homework on what these two are supposed to be about...


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Wed Aug 10, 2022 5:57 pm 
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Glad you got it sorted out and found the problem! Yes the wiring on these vehicles is nothing to brag about.
Right after I bought my Jeep used, I redid all the wiring looms in the engine area and even rerouted some of them from known problem areas.

As to your overheating problem on hills. Most likely a bad fan clutch. For much improved cooling, replace the factory fan and fan clutch with the GM 11 blade plastic fan and heavy duty fan clutch. The GM parts are designed for the big 6L V8 engines that came with HD towing and AC package and will cool your Jeep diesel much better than factory.
Quote:
NAPA Part no’s (fitment: Chevrolet Truck)
GM Severe Duty Fan Clutch NAPA PN: 271625
GM 11 blade HD Cooling Fan NAPA PN: 8552223
Requires four (4) GM 11516869 mounting bolts M10X1.5X18mm (mounts fan to clutch)

The GM Fan & Fan Clutch is designed for the GM 6.0L V8 engine with HD cooling, AC, w/towing package.
*ACDelco Fan Clutch PN: 20913877 or *GM Severe Duty Fan Clutch NAPA PN: 271625
*Hayden Fan Clutch PN: HY 2786 or 2986 or *Four Seasons PN: 36973
*ACDelco GM 11 Blade Fan: PN: 15976889 or NAPA PN: 8552223
Requires four (4) GM PN: 11516869 mounting bolts [4 M10X1.5X18mm bolts (mounts fan to fan clutch)] These bolts can also be sourced at most hardware and building supply stores.

*Note: The Hayden, Four Seasons, and GM/ACDelco parts can also be found online at Amazon, Rock Auto, and some of the GM Parts Vendors.


As to the fuel loosing prime when setting, you have a leak somewhere.
Most owners install the intank lift pump that was used in the early 2000's Dodge Cummins trucks. It is a direct drop in the tank replacement for the OEM fuel and fuel gauge module. All you have to do is add two additional wires to the harness from under the rear seat area to the top of the fuel tank. The vehicle is prewired for the lift pump, and a relay, and the correct logic in the ECM for the lift pump. The wires are already run all the way to under the rear seat to a connector, so you only have to add two wires.
See this:> http://www.auerbach.ca/kj/lift_pump/default.html

Image

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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Wed Aug 10, 2022 7:16 pm 
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Oh, this is a known problem area for wiring? Are there others?

I actually just installed the in-tank pump, wondered if one of those similarly un-brag-worthy fuel hose connectors was the culprit, but after sitting overnight, it started up just fine.

Fan clutch is brand new. My experience, mostly with gassers, makes me wonder why mechanical engine fans are even a thing. Yes, they can move more air than an electric, but only at higher RPM, not idle and low speeds when they're most needed. Every vehicle I've upgraded with an electric puller fan (augmenting the existing electric pusher fan), mostly overheating-prone BMWs, improved significantly in thermally stressful situations. Any reason not to do so here?

Meanwhile, I figured out the radiator bleed screw. Will know soon if that was enough.


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Thu Aug 11, 2022 12:23 am 
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Sorry about the long post, but a lot of things to cover you touched on!

The 11 blade GM fan moves much more air (CFM) than the OEM fan and it moves more air flow than most any size electric fan that you can fit into the limited space of this vehicle.
Some on this forum have actually tried going totally electric and ended up going back to a mechanical fan and several installed the GM fan & HD clutch and reported much better results than the electric.
The 11 blade GM fan & HD clutch does an excellent job in low speed stop and go town driving as well and when towing heavy loads on a trailer.

That is the reason I pioneered finding a better cooling fan back in 2014 to help provide the engine with better cooling and help with AC performance especially when stuck in stop and go traffic. That is when I figured out the big GM Fan & HD Fan Clutch for the 6L V8 engine would fit and function on the little 2.8 diesel engine.

With the OEM metal fan, the only time I ever had issues of engine temperatures going above normal was when towing a loaded trailer. The higher temperatures also affected transmission shifting, but AC performance at slow speeds was terrible.
With the advent of installing the 11 blade GM fan and HD fan clutch, I have never had any more problems with engine temperatures and AC performance in our 100+ degree days with humidity near 100% is greatly improved.
_____________
As to the fuel line fittings back at the fuel tank. Yes they are push on gasser type fittings and are not designed nor do they work well for vacuum fuel systems, they are designed for pressure fuel systems. So when used in a vacuum fuel system, they can and will allow air to be sucked into the fuel system.
Some owners have removed both of the push on fittings, one at the tank end, and one at the metal pipe end where it attaches to the frame.
(Still requires dropping the fuel tank to get to the fitting on top of the fuel tank module. Might as well put in an intank fuel pump while you got the tank dropped!) :juggle: :lol:
They replaced them with diesel rated hose and used either screw type clamps or crimp on clamps for a sure seal.
But, if you install an intank fuel pump, it puts the entire fuel system under low pressure (12-14 psig) from inside the fuel tank all the way to the back of the CP3 injection pump.
If you have a leak anywhere, it will be self evident very quickly under pressure as fuel will leak out instead of air being sucked into the system.
So the push on fuel line fittings will work just fine in a pressure system; mine are still in service with zero issues.
____________
As to other wiring issues, anywhere the harness is subjected to the constant rubbing and vibration of the diesel engine.
One known area that a few have had problems is where the harness passes behind and under the alternator bracket, it can rub there and cause a short.
Just a good overall inspection of all the harnesses in the engine bay area and renew any spots where the plastic sheathing has or is coming off, or any lose taped areas, or any places where the a harness is under stress or tight against the vibrating engine.

This is a picture of my harness when I was redoing it before I put it back in place to give you some ideas. :wink:
Not a lot of work or money involved, but could save you a ton of problems and headaches. :D

Image

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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 13, 2022 12:37 am 
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I drove around all day, at least 10 starts and stops, some 150 miles. There's no external fuel leak, but the pressure loss after shutdown is very much still there, and totally random. I remember reading something about defective early design filter housings? This one's an '05 and different from our parts '05. Off to do my homework...


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 13, 2022 1:40 am 
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moroza wrote:
I drove around all day, at least 10 starts and stops, some 150 miles. There's no external fuel leak, but the pressure loss after shutdown is very much still there, and totally random. I remember reading something about defective early design filter housings? This one's an '05 and different from our parts '05. Off to do my homework...

If you have a leak on the vacuum fuel system, it will suck air in, not leak fuel out. Intank fuel lift pump solves all air in fuel problems.

There is an upgraded fuel filter head, but replacing it will not solve air in fuel issues if you have a leak elsewhere.
Updated Fuel Filter Head (Liberty CRD) See picture 2
https://www.idparts.com/updated-fuel-fi ... -4723.html

The defect on the fuel filter head is the plug for the fuel heater. Most simply unplug it, spray it clean good with brake or carb cleaner, dry it, then fill it full of RTV sealer and let it cure.
The 12v fuel heater adds very little heat to the fuel, you will never miss it disconnected.

The fuel filter head is also a two piece design and has a gasket between the two halfs. Make sure it is tight.


Picture 1
Image

Picture 2, Upgraded Fuel Filter Head
Image

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GM11 Bld.fan/HDClutch
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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 13, 2022 2:43 pm 
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WWDiesel wrote:
Intank fuel lift pump solves all air in fuel problems.


:? That must mean the pump isn't working. Or whatever is supposed to keep the rail pressurized on both ends isn't. Investigating...


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 13, 2022 4:12 pm 
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moroza wrote:
WWDiesel wrote:
Intank fuel lift pump solves all air in fuel problems.

:? That must mean the pump isn't working. Or whatever is supposed to keep the rail pressurized on both ends isn't. Investigating...

These vehicles did not come from the factory with the low pressure intank lift pump installed although they should have.
Owners install the intank lift pump as an improvement (mod) to their vehicles to end all air in fuel issues. :wink:

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SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount

98 Dodge Cummins 24 Valve


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 13, 2022 9:46 pm 
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That's what's confusing; as I said above...

moroza wrote:
I actually just installed the in-tank pump, wondered if one of those similarly un-brag-worthy fuel hose connectors was the culprit


To be clear, I also installed the new wiring harness, though I didn't verify the pump was working before someone else put the tank in.

As far as the concepts of modification and improvement go, I'm at least passingly familiar.


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 Post subject: Re: Fleet o' Jeeps, software questions
PostPosted: Sat Aug 13, 2022 10:01 pm 
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Location: Central GA
moroza wrote:
That's what's confusing; as I said above...
moroza wrote:
I actually just installed the in-tank pump, wondered if one of those similarly un-brag-worthy fuel hose connectors was the culprit

To be clear, I also installed the new wiring harness, though I didn't verify the pump was working before someone else put the tank in.
As far as the concepts of modification and improvement go, I'm at least passingly familiar.

A simple pressure gauge will tell you right quick if it is functioning properly or not. Actually, I think you can even hear it running.
When you first turn the ign. switch to the ON position, the ECM will run the fuel pump for about 10-15 seconds. :D

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