2005 Jeep Liberty CRD Won't Start - At first no hot start...now no start at all

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jwilinski

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A PCM (powertrain control module) or ECM (engine control module) are not prone to complete failure except in some relatively rare circumstances (flooding, fires, voltage spikes from improper jump starting or even reverse polarity battery installs).

Used PCMs in supposedly working condition are hundreds of dollars, even more for a CRD PCM, and while plug n play remans are also available, either of these MUST first be reprogrammed with your actual VIN.

More importantly, while PCM failures can happen, OTHER important modules and.or sensors can fail more easily and more often and then send "wrong" or "null" info to the PCM. In that case, it is a sensor, and not the PCM, that is causing the engine to not run or run poorly. But that also means that you will not have fixed your problem by replacing the PCM unless you also replace the bad sensors. It also means that you might not even have a "bad PCM" like the mechanics are saying...it all depends on the DTC's (Diagnostic Trouble Codes) that the truck is throwing out!!

What to do??

Well... while it is potentially a good sign that both mechanics agree that the problem is the PCM, you need DEFINITELY them to tell you, or better yet show you, the actual DTCs which they retrieved from the PCM during their diagnosis procedure!!!

Unless you simply want to trust your mechanics, you MUST know ALL of these codes to REALLY determine what is going on

If not, you can go by an Oreillys and either they'll read them out for you or loan you the tool so you can do it yourself. Then write them down and post back here with them.

By knowing the actual DTCs, members here can then chime in with an EDUCATED opinion as to what the real problem is ... or if the PCM is in fact kaput.

Just my .02 ... Dont believe me??
You can read more about it at the link below--

Could this perhaps be the issue with the PCM? See attached photo. One red wire is not attached. Let me know your thoughts.
 

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jwilinski

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A PCM (powertrain control module) or ECM (engine control module) are not prone to complete failure except in some relatively rare circumstances (flooding, fires, voltage spikes from improper jump starting or even reverse polarity battery installs).

Used PCMs in supposedly working condition are hundreds of dollars, even more for a CRD PCM, and while plug n play remans are also available, either of these MUST first be reprogrammed with your actual VIN.

More importantly, while PCM failures can happen, OTHER important modules and.or sensors can fail more easily and more often and then send "wrong" or "null" info to the PCM. In that case, it is a sensor, and not the PCM, that is causing the engine to not run or run poorly. But that also means that you will not have fixed your problem by replacing the PCM unless you also replace the bad sensors. It also means that you might not even have a "bad PCM" like the mechanics are saying...it all depends on the DTC's (Diagnostic Trouble Codes) that the truck is throwing out!!

What to do??

Well... while it is potentially a good sign that both mechanics agree that the problem is the PCM, you need DEFINITELY them to tell you, or better yet show you, the actual DTCs which they retrieved from the PCM during their diagnosis procedure!!!

Unless you simply want to trust your mechanics, you MUST know ALL of these codes to REALLY determine what is going on

If not, you can go by an Oreillys and either they'll read them out for you or loan you the tool so you can do it yourself. Then write them down and post back here with them.

By knowing the actual DTCs, members here can then chime in with an EDUCATED opinion as to what the real problem is ... or if the PCM is in fact kaput.

Just my .02 ... Dont believe me??
You can read more about it at the link below--

Do you think this could be the problem with the PCM? See attached photo. One red wire is not attached and came loose at some point.
 

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jwilinski

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Poi si rompe del tutto e la jeep non parte piu. Il pezzo costa pochissimo e cambiarlo è questione di 15 minuti.. questa sera vado a casa e cerco il pezzo per fare foto è il sensore sopra al volano
Alf, Could this perhaps be the issue with the PCM? See attached photo. One red wire is not attached. Let me know your thoughts.
 

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jwilinski

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That's better, some proper diagnostics.
Looks like you need to get the PCM sent away for testing and possibly repair.
Could this perhaps be the issue with the PCM? See attached photo. One red wire is not attached. Let me know your thoughts.
 

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jwilinski

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So have they checked the sensors that the PCM uses to initiate fuel injection now?
As I mentioned earlier they are critical to a fault like this.... if the PCM doesn't receive a signal from the crank sensor it doesn't see the engine turning so won't inject any fuel, as its not seeing any rotation it won't log a fault.... (not sure on the cam sensor here I haven't had the joy of that failure yet!)

What is the fuel rail pressure on cranking?

Its possible that your PCM is faulty, there are companies that can test and repair them, you'll have to Google for someone near you for that, it's also possible to have yous cloned onto another one to avoid issues with the security system.

As Seafish says it would be interesting to see some proper diagnostic output, what makes them think it's the PCM?
I’m at a loss. I don’t know where the sensors are located in order to test them. I wouldn’t know how to test them even if I could find them. Also, I tried to take out the PCM to send it in to get it tested and possibly repaired (if it’s bad) but I took out two screws and it’s not coming out. Also, I don’t know how to detach the wire connectors. And finally, I noticed two red wires that are not attached to anything. See picture. Neither the diesel mechanic shop or the dealership are able to help me. I don’t know what to do next.
 

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jwilinski

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I live in Plymouth, MN a western suburb of Minneapolis. If anyone knows a decent mechanic that won’t just blow me off and actually might know what they’re doing especially as it relates to the PCM and sensors and related wiring for a 2005 Jeep Liberty CRD please let me know.
 

seafish

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I’m at a loss. I don’t know where the sensors are located in order to test them. I wouldn’t know how to test them even if I could find them. Also, I tried to take out the PCM to send it in to get it tested and possibly repaired (if it’s bad) but I took out two screws and it’s not coming out. Also, I don’t know how to detach the wire connectors. And finally, I noticed two red wires that are not attached to anything. See picture. Neither the diesel mechanic shop or the dealership are able to help me. I don’t know what to do next.

Sorry I have no idea if that red wire was put in by someone for an aftermarket product that simply may not be there anymore, or if it is part of the OEM wiring.

If it IS part of the OEM wiring, then it being cut could very well be the cause of at least part of your ECU problems.

If it is DIY wiring, but is poorly tied into the OEM harness, then it ALSO could be part of the cause of your ECU problems.

In short (no pun intended) its time to find a wiring diagram for your little truck!!!
 
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KJowner

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Just looked at mine, unfortunately you can't see anything as it's all wrapped up in loom tape, yours looks like someone has been monkeying with it! I wonder if it had remote start or an additional immobiliser once? I can see a taped up joint and different colour wires as well as the loose wire. Have you downloaded the manuals? There is a pinout for the connectors in there that should help you match up the oem wires to the plug. Search on here for a link to the site.
I would suspect that the two red wires with the yellow trace are actually the same wire cut in two, however check the drawing and see if you can follow the wires before joining them.

The two sensors are:
Crank angle - located behind the downpipe below the turbocharger on the bellowing.
It's a pain to change! Held in place with a single torx screw, I used a star bit taped into a short ratchet spanner ring because I couldn't get in with my 1/4 drive ratchet.
Cam angle - located in the back of the rockerbox cover.

You said that the garage had checked them? If you want to test them yourself there are videos on YouTube that will show you how a lot easier than me typing it here.

There is a guy on the Lost Jeeps form who is a mobile mechanic specialising in CRDs he may be able to help or suggest an ECU specialist in America, I'm fairly sure the same ECU is used in older BMWs and Land rovers diesels Bosch injection so it should be supported.
 

jwilinski

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Sorry I have no idea if that red wire was put in by someone for an aftermarket product that simply may not be there anymore, or if it is part of the OEM wiring.

If it IS part of the OEM wiring, then it being cut could very well be the cause of at least part of your ECU problems.

If it is DIY wiring, but is poorly tied into the OEM harness, then it ALSO could be part of the cause of your ECU problems.

In short (no pun intended) its time to find a wiring diagram for your little truck!!!
The owner before me put in a remote starter in…maybe this is what that goofy wiring is all about. I’ll find the wiring diagram. Thanks!
 

jwilinski

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Just looked at mine, unfortunately you can't see anything as it's all wrapped up in loom tape, yours looks like someone has been monkeying with it! I wonder if it had remote start or an additional immobiliser once? I can see a taped up joint and different colour wires as well as the loose wire. Have you downloaded the manuals? There is a pinout for the connectors in there that should help you match up the oem wires to the plug. Search on here for a link to the site.
I would suspect that the two red wires with the yellow trace are actually the same wire cut in two, however check the drawing and see if you can follow the wires before joining them.

The two sensors are:
Crank angle - located behind the downpipe below the turbocharger on the bellowing.
It's a pain to change! Held in place with a single torx screw, I used a star bit taped into a short ratchet spanner ring because I couldn't get in with my 1/4 drive ratchet.
Cam angle - located in the back of the rockerbox cover.

You said that the garage had checked them? If you want to test them yourself there are videos on YouTube that will show you how a lot easier than me typing it here.

There is a guy on the Lost Jeeps form who is a mobile mechanic specialising in CRDs he may be able to help or suggest an ECU specialist in America, I'm fairly sure the same ECU is used in older BMWs and Land rovers diesels Bosch injection so it should be supported.
Excellent information. Thank you so very much!! I now have that mechanic’s number and I will contact him.
 

jwilinski

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I connected the two wires and then tried to start the car and it started! It seems that the broken wire was part of a remote start component that was added manually by the previous owner. I’ve been driving it around for a few days. However, it still failed to hot start one time (but started again after I waited about 15 minutes) leading me to believe that the PCM should still be checked. Also, it died once while at a stop sign and the oil light came on for a few seconds… I started it right away and it started. What do you think about these developments? Should I send the PCM off to be checked and fixed still? If so, how can I get the pcm out? I took two small bolts out but now I can’t see where else it’s connected in order to get all the way off.
 

jwilinski

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I connected the two wires and then tried to start the car and it started! It seems that the broken wire was part of a remote start component that was added manually by the previous owner. I’ve been driving it around for a few days. However, it still failed to hot start one time (but started again after I waited about 15 minutes) leading me to believe that the PCM should still be checked. Also, it died once while at a stop sign and the oil light came on for a few seconds… I started it right away and it started. What do you think about these developments? Should I send the PCM off to be checked and fixed still? If so, how can I get the pcm out? I took two small bolts out but now I can’t see where else it’s connected in order to get all the way off.
Just out of curiosity, I disconnected the remote start wire just to see if it would start… and it did. So there goes the theory that I fixed the problem. I’m starting to think that the warmer weather in Minnesota lately may have been the reason it started recently. One other thing… the engine pretty much constantly chirps like a bird while idling. What’s that all about? Also, I need to know how to take out the PCM so I can mail it in to have it checked.
 

KJowner

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The chirp is probably a pulley bearing or something on the belt drive.
The fact the wires make no difference is strange, the only time I've seen temperature an issue is for crank angle sensors, usually they die when they get hot and come back to life when they cool down. I wonder if you have a broken wire or bad connection on one of the sensors or a poor connection in the plug the wires attach to.
 
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