thorguy57

If the check engine light doesn't illuminate for a second when you turn on the key and then disappear or stay on you are not getting power to the ECM. You need to track down the issue there. Take a meter and I can almost bet there is no power to the ECM.

thorguy57

I would still make sure you have 12 volts on one side of the auto shut down relay. If you do try jumping it out. If you don't have a good ground on the control side of the relay it won't close allowing power to the coil or injectors.

ronnorman_6

The pick up is like 50 dollars at autozone I would replace it. It wouldn't hurt to try

thorguy57

Don't just throw money and parts and a problem is not really there. If your ECU is not getting any power it has nothing to do with the pickup assembly.

uBapimp

I checked the ASD relay, it has 12v to it, and I swapped out that relay with my fan relay and it still won't start. Any other way to test power to the ECM?

thorguy57

Sorry I mislead you for a second. Ok Your ECU looks like it is powered from a 15 amp fuse out of the Power Distribution Center under the hood. It goes to a Red/ DK BLU wire down to the ECU. You will have to check that wire on the connector down at the ECU. Here is where it is wired a little weird though. It looks like out of the distribution center it is a DK BLU/ White wire then into a Ballast Resistor Relay. If the coil is open on the Resistor relay you will NOT get power to the ECU. Seems a wierd way to wire it but it is what it is. Like I ssaid check the RED/DK BLU wire at the ecu and see if you have 12V.

TheDale

Where is the ASD relay? I can't find it in my Chilton book.

uBapimp

It's in the fusebox on the passenger side behind the battery. There is a diagram on the inside of the cover on the box and that will show you which relay is the ASD.

TheDale

Oh ok. I will have to try and find a diagram. My fusebox cover is gone.

uBapimp

Problem finally solved. I broke down and took my jeep into the shop, courtesy automotive in Colorado Springs. They did a great job too. I'll be going to them for anything I can't figure out in the future.

They couldn't get a reading off of the ECU and none of the sensors were receiving a 5 volt excitation. So after testing every sensor they determined that their was a short in the Crankshaft Position Sensor.... Yes the one I had already replaced.

So, shame on me for not testing the resistance of the supposedly new sensor I bought from an auto parts store who shall remain nameless... ::cough cough:: Autozone ::cough cough::

The technician at Courtesy Automotive, which is a NAPA shop, explained how Autozone and O'Rielly get their replacement parts through a bidding system in which inferior products are produced at cheaper rates so a manufacturer can win the bid to sell their item through the parts retailer. He explained that NAPA manufactures all of their own parts as either carbon copies of OEM parts or re-manufactured OEM parts themselves.

Needless to say, I will be going to NAPA for all of my replacement parts. Autozone has lost my trust and business. I am currently trying to get my money back for the shotty part they sold me, and that is a hassle within itself. Autozone cannot directly refund my money. They can only replace the part, probably with yet another defective one. I must send the part to the manufacturer directly and after they've tested it they might refund my money and pay for a portion of the work I had to have done as a result of their inferior product.

This has left quite the bitter taste in my mouth, and I hope it can serve as a warning to others. Avoid Autozone and O'Rielly despite their alluringly low prices. It's not worth the price you'll pay in the end. I'm not even going to purchase windshield washer fluid from them anymore.

And finally thanks to everyone who helped me track down the problem in this case. You were all spot on with your diagnoses and I appreciate it.

tjwalker

There is a big difference in sensor reliability. I worked for 23 years in Test Engineering for Honeywell, where some of our products were OEM automotive sensors.

Can't tell you how much junk we picked up from our competitors for testing. And even if it did work out of the box, the "longevity" wasn't there. And that is really important for most people. Don't care if you have a lifetime warranty, reliability is more important. A bad crank sensor can leave you on the side of the road, and they aren't that easy to replace in the dark in zero degree weather.

I buy plenty of aftermarket parts, but for the above reasons, I buy my sensors directly from Jeep as I know where they source their sensors. #2 choice is Napa as they are more particular about their sources. All others, buyer beware, you may get lucky, you may not.

And stay away from ebay engine management sensors at all costs, unless you have confirmed a name brand. There is a whole bunch of crap floating on that bay.

The Rooster

this info has been noted...thank you

Garvin

You guys may praise NAPA but the NAPA's arond me have done me nothing but wrong. I got an alternator from them for my old Cherokee just to have it go bad in 3 days. I got it replaced just to have it go bad again within a day. Within a week, that alternator was replaced 5 times to have nothing but problems. I ended up going to Advance Auto Parts to get an alternator and it worked instantly and worked till the Cherokee was totaled, over a year later.

The guy at NAPA kept insisting that there was something wrong with my charging system and was a pain in the butt to even get a replacement even though they had it right on the shelf. I had to basically drag him out of the store and show him that the Advance alternator was working perfectly fine on my volt gauge and with a DMM. All this hassle and I didn't even get a core back or my money back for a core, so I was out another $30!

This isn't the first time something like this happened. The first incident like this happened with another alternator issue in a Pontiac when I worked at a private garage where it was replaced 4 times with duds and we ended up getting an alternator from somewhere else.

Had another issue where they kept giving the wrong sensors to my buddy when I was rebuilding his transfer case. They gave him 4 wrong ones before I went there and made them look it up while I was staring at the screen. Apparently they made two different seals and they gave my buddy 4 diff brands of the same seal, which was the one that wouldn't fit his even though it clearly said on there they were different.

That's just three of the MANY bad experiences I've had or heard with them from my buddies.

I rarely shop at Autozone though, I mainly do all my shopping at Advance Auto Parts. Their parts have yet to do me any harm and I've been shopping there for my buddies and families vehicles for about a decade now.

99KeeSport

Sorry you had to learn a lesson about the trinity: fuel, spark, air. We've all been there my Jeep brother.

Just remember a few key things:
--If it 'cranks' it's not the nuetral safety switch
--If there is no spark (but cranks) it is most likely the CPS
--Don't assume you have fuel in the chamber until you SEE fuel spurt from an injector (loosen the fuel rail and take an injector out slightly and crank the engine with the coil disconnected)

I recently went through a spark mystery. I had spark but apparently it wasn't 'strong enough'. A new (autozone) coil fixed the issue. Vaa-rooom!

Autozone is great for those times that you just can't afford the prices at NAPA. I always get sticker shock at NAPA and my local NAPA shops have a requirement that you have to be an A-hole to work there. My po-dunk NAPA closest to me always says "I can have it here a week after the the planets are aligned." Or, I need to drive into the city and deal with a-holes that probably can't change their own oil. Sorry, I'll stop ranting.

I've had great luck overall with Advance Auto. They sell the 'better' TRW and MOG parts. With their on again-off again 20% off sales on their website, it's nice to time repairs when they offer the discount. If I owned Advance Auto, I'd just keep the prices 20% less.

truckntractorhick

hmm....... same problems here...... but i think my ECM is shot.