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-   -   2004 JGC Not starting (http://www.jeepgarage.org/f196/2004-jgc-not-starting-22307.html)

Nissala 04-25-2011 12:18 PM

2004 JGC Not starting
 
I purchased a 2004 Jeep Grand Cherokee limited in February. All was well until yesterday. It will not start, it turns over but will not start. The Sentry key light is on, but not flashing. I called a locksmith (at the suggestion of the used car dealership I purchased it from) he tried to reprogram the key to no avail (but still charged me!). I have tried unplugging the negative battery cable and the PCM fuse, tried locking and unlocking with both the key and the fob.

Can anyone make any suggestions?

Thank you in advance for your help. :confused:

2005JGC 04-25-2011 01:24 PM

Re: 2004 JGC Not starting
 
First of all do a key dance, starting with key off, go to on, off, on, off, and back to on (leave it on). Your cluster will display any dtc,s in the PCM. That will be your biggest help. If you have a skim issue there should be an invalid skim key code in the PCM.

Note: better to do with fuel pressure gauge. Pop the cap off the fuel rail (bank 2 fuel rail, passanger side). With safety glasses on take a screwdriver, turn the key on, then using the screw driver poke in the schrader valve in on that fuel rail port. If fuel sprays you have pressure, if it doesnt you have no pressure. If you have no pressure, have someone crank the vehicle while you climb under the back and give the fuel tank a nice couple of bangs from a dead blow... if it starts, get it to where you want to replace the fuel pump at ASAP because it likely wont continue running.

Issues with the skim key. IF it is a problem with the skim key you have likely locked the skim module up by trying to start it repeatedly, just reprogramming the key wont resolve a skim lockup. Infact it would kinda point away from that being the issue if there was no issue reprogramming the key again. BUT if it was an issue you can attempt to unlock the skim by placing the vehicle on a battery charger, turn the key on and let it sit for 1.5 hrs.

I would lean towards fuel pump issues... could also be CKP or CMP sensors too... but it seems like 4 times out of 10, a tow in wj is going to be a fuel pump. IIRC, the skim light turns on for a moment reguardless of proper key or not. My first step would be a key dance, slap the fuel pressure gauge on and a noid light on an injector. this gives me codes, lets me know if I have pressure and if my CMP and CKP sensors are functional if my noid light flashes (because its telling it to fire).


Also, if you want to throw parts at a car to repair it (programming a key), you cannot expect innocent persons doing what you ask to do it for free becasue your assumption wasnt correct. You gotta pay to play ;)

btw this is the WK section (2005-2010) not the WJ section (1999-2004) ;)

2005 WK 04-26-2011 06:46 PM

Re: 2004 JGC Not starting
 
I had a similar problem to this in my 2003 and I also thought it was the key so I had one made but after taking it to 3 mechanics and they couldnt figure it out, i took it to the dealership. Turned out to be the crankshaft position sensor. Had them put a new one on and never had the problem again.

2005JGC 04-27-2011 01:47 PM

Re: 2004 JGC Not starting
 
^^ Yes, the CKP and i believe O2 sensors on the 4.0l are common for shorting out and bringing down the bus... If you put a multi meter on an easily accessable 5v sensor supply you will find no voltage, unplug your CKP and your 5v would come back to life.

Frango100 04-27-2011 02:07 PM

Re: 2004 JGC Not starting
 
Sentry key light flashing means invalid key or transponder problem. Sentry key light on steady normally means a fault detected in the system by the SKIM (Sentry Key Imobilizer Module). As far as i know you need a DRBIII scanner to read the faults stored in the SKIM. When switching on the ignition, the SKIS does a self test and the sentry key light should be lit for 3 sec. and go out, for the light bulb check.
I'm not sure if any fault will be shown related to the SKIS when doing the key dance.
But i'm almost sure that your problem is related to the not valid signal from the SKIM to the PCM and not sensor or fuel pressure related.
Did you try to directly start the engine without pausing the ignition switch in the normal position? Because when it is SKIM related, the engine should start and turn off after 2-3 sec.

2005JGC 04-27-2011 02:53 PM

Re: 2004 JGC Not starting
 
the CKP brings down the bus when shorted... aka no communication. Typically the car comes in on the hook, no start, and it acts like a skim issue... But you measure for 5v to any 5v sensor and its not there.

Frango100 04-27-2011 04:47 PM

Re: 2004 JGC Not starting
 
Ok, but when the SKIS light is on, it means that the SKIM doesn't allow the PCM to run for more then 2 sec. Would you have this light when there is a problem with the CKP?

2005JGC 04-28-2011 12:39 AM

Re: 2004 JGC Not starting
 
no, not peticularly, but a shorted crank sensor CAN bring the bus down causing skim issues. I have seen it a number of times.

Nissala 04-29-2011 02:04 PM

Re: 2004 JGC Not starting
 
Thanks for all the input. Nothing has worked so had it towed to the dealership Wednesday, who are still perplexed by this issue and have contacted Chrystler engineers for help figuring it out. The mechanic said it's turning into a nightmare....

I will post again whemthe solution is found, just in case anyone else has this issue.

Thanks again for the suggestions! :-)

2005jeepgrandcherokee 05-07-2011 08:04 PM

Re: 2004 JGC Not starting
 
have they ever figured it out ?

Towerman 05-17-2011 08:53 AM

Re: 2004 JGC Not starting
 
Quote:

Originally Posted by Nissala (Post 402830)
I purchased a 2004 Jeep Grand Cherokee limited in February. All was well until yesterday. It will not start, it turns over but will not start. The Sentry key light is on, but not flashing. I called a locksmith (at the suggestion of the used car dealership I purchased it from) he tried to reprogram the key to no avail (but still charged me!). I have tried unplugging the negative battery cable and the PCM fuse, tried locking and unlocking with both the key and the fob.

Can anyone make any suggestions?

Thank you in advance for your help. :confused:

I have already been through this with my 2004 Rocky Mountain Edition - CPS (Crankshaft Position Sensor) is the most likely culprit. What I will tell you is that unless you are a very talented contortionist - this is one of those repairs you want your mechanic to do on a lift.

Trying to snake that sensor along the top of the bell housing of the transmission to the wiring harness is not fun...all I have to say about that. If you do decide to try it yourself, make sure that your Jeep has sat for at least an hour to let everything cool off.

2005JGC 05-17-2011 12:29 PM

Re: 2004 JGC Not starting
 
Quote:

Originally Posted by Towerman (Post 416232)
I have already been through this with my 2004 Rocky Mountain Edition - CPS (Crankshaft Position Sensor) is the most likely culprit. What I will tell you is that unless you are a very talented contortionist - this is one of those repairs you want your mechanic to do on a lift.

Trying to snake that sensor along the top of the bell housing of the transmission to the wiring harness is not fun...all I have to say about that. If you do decide to try it yourself, make sure that your Jeep has sat for at least an hour to let everything cool off.

truth...

Like I have said... they need to just stick a dvom on the sensor supply circuit, I promise there is no supply on it because there is one sensor shorted internally. From there all you do is unplug sensors that use that supply until you reach a sensor that your 5v magically comes back when unplugged *cough* CKP SENSOR *cough*

I cannot remember all the symptoms but EVERY time this problem comes in on the hook, the customer just wants their key programmed... NOT going to work ;)


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