Pcm problems

[Jmm5712]

I bought an 03 expy,eddie bauer edition 4x4 5.4 v8.drove it home with the avtrac light on.then an hour later tried to back outof my driveway and a god awful noise was coming from the back tire.the low tire indicator light and abs light came on.it seemed to have a bad miss and barely wanted to get out of its own way. So i took it to a trusted mechanic that suspected a wiring issue or pcm issue.turns out it needs a pcm.i found a place in north Carolina that sells remanned and reflashed pcms and say that its plug and play as long as u call them with your vin number.my question is,b4 i dump another 300 or more for a reflashed pcm is it even going to work?or is there going to be another issue with keys and ignition?ive had some people tell me the ignition will need replaced or ill have to get different keys,please somebody help me out here.i bought this vehicle and drovvit one day and its been in the shop ever since.id love to get it back on the road

 

[stamp11127]

Welcome to the site.

Unless the PAT'S system has changed, the pcm and instrument cluster are married together. Doubt it would be plug and play.

How did your mechanic arrive with the conclusion the pcm is faulty?

 

[Jmm5712]

Well at first he thought it was a wiring issue,then it was throwing codes that dont make sense such as one side of the engine running rich and the other running lean.i trust his work,as he tried for a month to straighten it out and only charged me $30 for all of his time and effort.so he told my husband the computer is shot and he has tried some from a junk yard with no luck so what do i need to do without taking it to a dealer?

 

[docraymund]

First off, get your truck back home in your garage even if you have it towed. Unnecessary bills can pile up and you are at the mercy of your mechanic. Members here can help you if you are inclined to do some tinkering.

 

[stamp11127]

It is possible to have one bank lean and the other rich. Time to find another mechanic or hit the books to learn how the system operates.

This is a rough anology but think of the pcm as any electronic device you have at home. When it fails it isn't minor failures, it is usually major errors or doesn't work.

You may want to look at the grounds to the vehicle and check the pcm grounds for corrosion. The winter salt raises hell with electrical.

 

[Jmm5712]

I'm picking it up on friday,and I'm willing to do whatever it takes to get this thing back up and running.thanks for the input.

 

[Jmm5712]

After reading many complaints of expy problems for this year 03,i think we will check the fuse panel-relay panel seeing that the drain hose for the sunroof runs directly behind this.hopefully we can get ti the root of the problem. Any other tips or things to check?

 

[Jmm5712]

I checked the fuse panel and there was water underneath where the main wiring harness runs,i popped out the rubber stopper and now if any water comes in it wont lay against the wiring harness.i had some dead fuses,going to do plugs first and a brake line and coil packs later in the week.im getting the check avtrac message displayed upon every start and tire pressure sensor failure or warning low tire occasionally. Any ideas suggestions?