Shut off at freeway speed

Crdlibbywa · **Posted:** Sat Apr 30, 2022 10:42 pm

Jeep shut off going 80mph on the freeway. Throwing a p0090 and p2294. I currently have the entire front of the Jeep off due to having a broken wire issue before figured this was a similar issue. Have been probing and testing all the wires in I can follow and haven’t found any new ones. Replaced the wire that went bad last time just to be sure it wasn’t my connections. Have a service manual and have been following all the diagnosis to test and it seems to be passing all the tests for the asd system and ecm. Checking voltage at the 3 sensors I can find on the circuit I’m only getting 3.1 instead of 5v but I’m getting 12v on the other wire at the same plug. Can’t seem to find any information in the manual about what would cause this or how to fix it. I replaced the crank and cam sensor just to eliminate those as the cause. Every sensor wire in the circuit ohm tests good back to the ecm. I’m assuming that the ecm is bad but hoping maybe I missed something and someone here could help shed some light.

Crdlibbywa · **Posted:** Fri May 06, 2022 12:24 am

Anyone on here have a ecm they are wanting to sell? After testing for hours it seems I have a short to voltage somewhere so I’m assuming it’s internal in the ecm.

synthetic-oil · **Joined:** Tue Sep 24, 2013 8:03 pm **Posts:** 140

I sent mine to https://www.solopcms.com/. Fast turn around. Lifetime warranty.

My66dodge · **Posted:** Sat May 07, 2022 8:29 am

My shop uses xemodex out of canada but they only deal with shops, they are very good

Sent from my iPad using Tapatalk

Crdlibbywa · **Posted:** Tue May 17, 2022 11:09 pm

Got the ecm back from solo auto electronics and still having the same issue. Said they replaced some stuff inside to the tune of 600 bucks but I’m still getting voltage on both legs of sensor with them unplugged. Still showing the same codes on the scanner and still won’t start. All wires and plugs test good so not sure where too go from here.

Mountainman · **Posted:** Tue May 17, 2022 11:51 pm

See if the pin on the ecu for the fuel pressure solenoid looks dark or crispy compared to the others. I've seen it on more than one of these jeeps. 5 minute fix if so

Billybob · **Posted:** Wed May 18, 2022 2:25 am

What year/model is your Jeep?

I can look through the Logics to maybe advise you.

Most of the circuitry...but not all... works by having +12 volts on one side of the component and the other side gets switched through to ground by by the ECM/PCM etc.

If you have +12 volts on both sides of the component then it is not getting switched to ground!

Bad contacts, broken wires and wires shorting to ground or to other wires are the usual culprits.....been there done that plenty times after my GF pranged my Jeep into a tree! :wink:

Crdlibbywa · **Posted:** Wed May 18, 2022 9:17 pm

All the pins in the ecm look the same. Nothing looks burnt or corroded. I would hope all of that got inspected while they replaced some parts internally. I called them today and they told me there is no software adjustments made only components replaced that where bad so it has to be in the wiring I just can’t seem to find it. I’m getting 12v on one side of the plug and 3.1 on the other side with both sensors unplugged. That’s why I assumed it was the ecm causing the problem.

It is a 2006 Jeep Liberty sport I’m guessing only badging it has is the trail rated badges.

Crdlibbywa · **Posted:** Wed May 18, 2022 9:28 pm

While cranking the Jeep over and back probing it 12v leg drops down voltage to around 10v and the 3.2v leg stays at 3.2v. If that helps narrow anything down. All the testing I have been doing is seems to come out with a short to voltage.

WWDiesel · **Posted:** Wed May 18, 2022 10:15 pm

The codes you listed:
P0090 -- Fuel Quantity (metering) solenoid – open circuit Wiring open circuit, Fuel Quantity (metering) solenoid, ECM
P2294 -- Fuel Pressure Regulator 2 Control Circuit Open

Which sensors have you tested and and what was the voltage you reading at each one.
Post and maybe we can help you by looking at the wiring diagrams.
Post year model:
Sensor (name) voltage readings on each legs, (No. of wires & wiring color codes) connected or disconnected when testing.

This drawing may be of help?

Crdlibbywa · **Posted:** Wed May 18, 2022 11:01 pm

The only two sensors that correlate with the codes and diagrams that I have from the service manual. Both sensors unplugged at the time of test also but have tried it with one plugged in and testing the other. Both are 2 wire sensors and it’s a 2006

Fuel quality sensor-unplugged
12v and 3.2v

Fuel pressure solenoid-unplugged
12v and 3.2v

Both sensors also ohm test good on both ends in the plugs. They are direct wires from sensors to ecm in twisted pairs.

WWDiesel · **Posted:** Wed May 18, 2022 11:49 pm

According to what I have on file, both solenoids in question are supplied 12v from the ECM and are controlled by the ground side wire from the ECM via a pulse width modulation signal.
Just curious, where are you located, your profile has no signature.

Crdlibbywa · **Posted:** Thu May 19, 2022 9:27 pm

I’m located in central Washington state. There used to be guy close that worked on them but I can’t find his number or info from the last time.

WWDiesel · **Posted:** Thu May 19, 2022 9:58 pm

Crdlibbywa wrote:

I’m located in central Washington state. There used to be guy close that worked on them but I can’t find his number or info from the last time.

Please update your profile (signature) when you have time.

My66dodge on this forum is in Kennewick WA and owns one and works on them. He also works at a automotive repair facility.
You could reach out to him and see if he could help you out any.

Message him or email him using the PM button or the eMail button at the bottom of his post he posted earlier in this thread.
viewtopic.php?p=950473#p950473

Crdlibbywa · **Posted:** Thu May 19, 2022 10:34 pm

That’s sounds familiar I will try reaching out to him. Thank you.

Billybob · **Posted:** Fri May 20, 2022 2:49 am

I presume you are aware that the LHD 2006 CRD has an issue whereby the Fuel Filter Mounting Bracket tends to compress a large wire harness down onto the firewall.

This causes shorts to ground and can cause some wires to short through to other wires!

So undo the Fuel Filter Mounting Bracket and carefully inspect the wiring in that area for any damage! :wink:

Crdlibbywa · **Posted:** Fri May 20, 2022 8:39 am

That section was all addressed last time I had an issue with it. I did take it all apart again and I can not find any damages in any of the harnesses. I even pulled the harness out of the front tray and inspected everything I can. Have also ohm tested as many wires as I can trace and follow. With the ecm know to be good now I know that it has to be a wire somewhere I just can’t find it.

Billybob · **Posted:** Fri May 20, 2022 9:33 am

Which pages are you looking at in the 2006 CRD Logic Diagrams......makes it easier for me to get to the same pages as you are on! :wink:

WWDiesel · **Posted:** Fri May 20, 2022 11:56 am

Just a thought, I don't believe you ever stated.
If you have the harness unplugged from the ECM, do you still get the same voltage readings on one or both legs at the sensor connectors end?
If you do, then that would tell you it is picking up the voltage in the wiring harness somewhere and not coming from the ECM.
:idea:

Billybob · **Posted:** Sat May 21, 2022 10:08 am

If the one leg of the "Solenoid Fuel Pressure" and of the "Solenoid Fuel Quantity Solenoid" are "Pulse Width Modulation" as WWDiesel states then you need to place an Oscilloscope there to see what is going on! Using a Digital Meter there is meaningless! :shock:

So looking at wiring Diagram 8W-30-14 these "control " wires would appear to be the Brown wire from C1 Pin 52 and the Brown/Yellow Stripe wire from C1 pin 76.

You could try spraying some Contact Cleaner on these contacts at the ECM and the C1 Connector...the contacts on the connector and the ECM are very delicate....the Dealers use an Extender Block fitted between the Connector and the ECM so as to be able to get their instruments into those positions without damaging the contacts.

You can try unplugging the C1 connector...with battery disconnected.....and measure with your Ohm meter from the pins at the two relevant solenoids to ground....should be no continuity to ground if the C1 plug is disconnected!

Make sure you are not holding the leads of your meter with your bare hands while doing these measurements!

When I do measurements on wires like this with a meter I tape a sharp pin or needle onto my meter leads and piece the insulation of the wires themselves...you can close up any holes in the insulation afterwards with some glue or melt the insulation.

This way you can check for shorts to ground and for continuity from end to end! :wink:

These Sensors themselves may be faulty if the failure only shows up at Freeway Speeds!

Check the ECM Ground is clean and tight...the Black/Dark Green wires going to G100 as shown on the diagram.

Shut off at freeway speed

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