2007 Chevrolet Silverado start/run problems

[Scorpyd]

I have a 2007 Silverado 1500 with the 4.3 in it, no 4x4, and i have been having some problems with it. Until today it wouldnt turn over. The truck electronics would shut off sometimes going down the road and cause the truck to shut off for a split second and catch on again. Doesnt happen every day but one day it left me stranded with no electronics or ignition so i hitchhiked a little for another battery and all said and done, it ran fine. A month later, which is today, the truck turned on electronic wise but didnt even try to crank the motor so i thought it was starter and changed that out a few hours ago. It still will not turn over but will have electronics. Its left me sitting in the water with this one, any ideas?

[04BlackMagic]

This sounds like the ignition cylinder. (Where u put the key to start truck) the contacts inside might be worn or possibly a dirty ground going to the ignition cylinder itself. Since it is intermittent, I would go look for a dirty/loose ground wire first. A dirty ground can cause some weird things. If the truck shut down electronically, the ignition cylinder told it to do so.

What kind of battery did u get? Does it have the proper amount of CA? Cranking Amps. This will also cause the truck not to turn over




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[04BlackMagic]

Or you may have a parasitic draw on the battery too. Unless the "New battery" stays at proper voltage


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[Supreme Pizza]

Replacing parts is not a good way to diagnose a vehicle. For the cost of that starter and battery, you could have just had it professionally diagnosed. You can test your battery for free at any local parts store. You can remove the starter and have it bench tested for free, or you can climb under the vehicle and test the starter with jumper cables or a screw driver. Always test things before replacing them. 

 

   That being said, I would look at the ignition switch (not the tumbler). Pull the plastic covers off of your steering column, and probe the starter wire with a volt meter while the key is in the crank position. If its getting 12V+, then your ignition switch is not the problem. Maybe the relays are failing. You can test them by swapping them around with other relays that have the same part numbers on them. 

 

     You can find the wiring diagrams in a Chilton repair manual, or by Googling it. 

[swathdiver]

Check your battery cables, not just the connections for corrosion.  BOTH positive and negative and check the grounds too.  A Tech2 would be nice to have to solve this without throwing parts at it.

[Scorpyd]

Update: Took to shop Wednesday, today (Friday) told me my ECM was broke/fried and will need another one. Is getting replaced, driving it again monday or tuesday

[Supreme Pizza]

Replacement ECM? 

 

I see shops replacing those all the time, even when it is not necessary. They replace the ECM, and a relay or fuse in the fuse box, and your $12 problem is fixed for $900. 

 

Did you try cleaning the electrical connections to the ECM? There are between 50 and 200 individual electrical connections, and if any one of them is corroded, the ECM may not work properly. You can clean them with electrical contact cleaner, and a soft bristled brush. Then apply some dialectic grease, and test it out. 

 

If you decide to go ahead and replace the ECM, it takes about 15 minutes to swap it out. Its 2 bolts, and can easily be accessed from under the hood. 

 

You can buy ECM's on eBay for about $150, which come pre-programmed to your vehicle, and with free expedited shipping. 

 

 

https://www.ebay.com/itm/2007-Silverado-Engine-computer-12597121-Programmed-to-your-VIN-ECM-PCM-ECU/183318293112?epid=1153364879&hash=item2aae9f2a78%3Ag%3AUnkAAOSwax5Yuh95%3Asc%3AUSPSPriority!98292!US!-1&_sacat=0&_nkw=2007+silverado+ecm&_from=R40&rt=nc&LH_TitleDesc=0

 

[Scorpyd]

Before i approved of it, they shown me this. I told them to go ahead. I havent cleaned the connections to the ECM. But by the way theyre talking about this, i’m going to have a aftermarket ECM and a person from that company is supposed to perform a software reflash and force feed my system

[Scorpyd]

[carnau]

On 7/27/2018 at 4:30 PM, Scorpyd said:

I have a 2007 Silverado 1500 with the 4.3 in it, no 4x4, and i have been having some problems with it. Until today it wouldnt turn over. The truck electronics would shut off sometimes going down the road and cause the truck to shut off for a split second and catch on again. Doesnt happen every day but one day it left me stranded with no electronics or ignition so i hitchhiked a little for another battery and all said and done, it ran fine. A month later, which is today, the truck turned on electronic wise but didnt even try to crank the motor so i thought it was starter and changed that out a few hours ago. It still will not turn over but will have electronics. Its left me sitting in the water with this one, any ideas?

 

On 8/1/2018 at 8:03 AM, swathdiver said:

Check your battery cables, not just the connections for corrosion.  BOTH positive and negative and check the grounds too.  A Tech2 would be nice to have to solve this without throwing parts at it.

I have run into alot of Battery cable failures causing this issue. Especially the Negative cables dropping voltage. Doing a loaded voltage drop test would help get tot he bottom of this. But like above, unless you have a tech 2 more than likely you will be throwing parts at it. 

I can really count on one hand how many ECM/PCM's have actually been the cause of an issue. Normally there is an underlying problem. 

[Scorpyd]

I know they tested my battery and told me that was good and couldn’t get the truck to communicate with the scanner either, shouldve mentioned that in above