01 Silverado won't run after disconnecting the battery

[gregintenn]

This truck ran great until I disconnected the battery today while working on it. When I reconnected the battery, the fuel gauge was pointing straight down. and the truck would crank, but immediately shut off. It also will not communicate with my code scanner. This makes me believe it is an issue with the body control module.

Anybody know how to reset it?

[No_0ne]

My first try would be to disconnect the neutral cable, then short that cable over to the positive lead for about 60 seconds.  That's often long enough to cause the computers to reset to defaults ...

[swiley383]

You said you were working on it what were you doing? I have 01 I had to replace head gaskets on and managed to forget to plug the crank sensor back in.

[gregintenn]

10 hours ago, swiley383 said:

You said you were working on it what were you doing? I have 01 I had to replace head gaskets on and managed to forget to plug the crank sensor back in.

Replaced the ABS control module.

[Guest]

This may not be super helpful, but I'd first double check that i didn't miss reconnecting something and that all connections are snug (for example if it cranked but shut off did a battery cable lose connection if it wasn't tight and it cranked). 

Then while also not super likely i might unplug the new ABS module in case its confusing the computer somehow? 

 

[Guest]

Sounds like a different issue, but just in case (cause this really surprised me), we had a different make, different year, that had a FOB and if you started it with key but it couldn't communicate with the FOB, it would shut itself right off after 1-2 sec.  Totally idiotic design and great way to be stranded...

[gregintenn]

I unhooked the battery a while back, and had trouble starting it then. Once it finally started, it ran like new again. This time it ain't starting.

A google search shows this to be a common problem, but so far I haven't really read a solution for it.

[bersaguy]

1 hour ago, BlessTheUSA said:

This may not be super helpful, but I'd first double check that i didn't miss reconnecting something and that all connections are snug (for example if it cranked but shut off did a battery cable lose connection if it wasn't tight and it cranked). 

Then while also not super likely i might unplug the new ABS module in case its confusing the computer somehow? 

 

To begin with if the vehicle started, once it did you should be able to unhook the battery and the vehicle should remain running because it runs off the alternator voltage and not the battery voltage. The battery is only designed to store energy to operate things such as the starter and things that do not require the motor running.

[swiley383]

Any code showing in the ECU? I would also check all the fuses? Can you hear the fuel pump running?

[gregintenn]

14 minutes ago, swiley383 said:

Any code showing in the ECU? I would also check all the fuses? Can you hear the fuel pump running?

I do hear the fuel pump. I can't find a bad fuse. The only code was for the bad ABS control module. Now, however, it will not communicate with my code reader.

[Erik88]

52 minutes ago, gregintenn said:

I do hear the fuel pump. I can't find a bad fuse. The only code was for the bad ABS control module. Now, however, it will not communicate with my code reader.

 

I almost wonder if your new part was a dud. It's happened before. I'm not sure why that ABS module would keep it from starting though.

[TomInMN]

52 minutes ago, gregintenn said:

I do hear the fuel pump. I can't find a bad fuse. The only code was for the bad ABS control module. Now, however, it will not communicate with my code reader.

There's a way to jump the terminals (I used fancy custom bent a paperclip) and have the check engine light flash the code at you. I think it was in the manual for my Blazer or S-10, maybe both. That might be a way to get a code.

[No_0ne]

2 hours ago, bersaguy said:

To begin with if the vehicle started, once it did you should be able to unhook the battery and the vehicle should remain running because it runs off the alternator voltage and not the battery voltage. The battery is only designed to store energy to operate things such as the starter and things that do not require the motor running.

While that was true years ago, modern cars often have circuit protection built in that will shut the alternator down when it senses low, or no battery voltage.  The battery does a lot more than provide energy for starting, it also acts to smooth out spikes in the line voltage, provides some measure against over-current situations, and generally acts as a "damper" to contain the normal transients in every type of charging system ...

[gregintenn]

O.k. I unplug the replacement brake control module and truck runs fine. plug it back in and it's a no go.

[bersaguy]

4 hours ago, No_0ne said:

While that was true years ago, modern cars often have circuit protection built in that will shut the alternator down when it senses low, or no battery voltage.  The battery does a lot more than provide energy for starting, it also acts to smooth out spikes in the line voltage, provides some measure against over-current situations, and generally acts as a "damper" to contain the normal transients in every type of charging system ...

Well, I have ben out of the repair business since the mid 90's so I am not going to challenge what you have said. I got out of the business when my health failed but I said back about 1990 tht I would quit working on them when they got smarter than I was and that was about 1993 or 94......

[gregintenn]

3 minutes ago, bersaguy said:

Well, I have ben out of the repair business since the mid 90's so I am not going to challenge what you have said. I got out of the business when my health failed but I said back about 1990 tht I would quit working on them when they got smarter than I was and that was about 1993 or 94......

Trust me. The are ALL computers now.

[bersaguy]

2 minutes ago, gregintenn said:

Trust me. The are ALL computers now.

Ain't technology great!!! That is why I'm driving a 1997 Jeep Cherokee. I can still work on it for the most part and then if I get in over my head I call my son to bring his service truck to the house and work on it. He has a mobile service truck and will do repairs on site in a persons driveway if they don't want to pay a big tow bill. His on site service has a 25 dollar fee that is a lot cheaper than a tow truck these days. He has all the computer scanners foreign and domestic chips through 2017 and will update chips again in 2020. Most cars these days have decade long warranties.

[gregintenn]

7 minutes ago, bersaguy said:

Ain't technology great!!! That is why I'm driving a 1997 Jeep Cherokee. I can still work on it for the most part and then if I get in over my head I call my son to bring his service truck to the house and work on it. He has a mobile service truck and will do repairs on site in a persons driveway if they don't want to pay a big tow bill. His on site service has a 25 dollar fee that is a lot cheaper than a tow truck these days. He has all the computer scanners foreign and domestic chips through 2017 and will update chips again in 2020. Most cars these days have decade long warranties.

Technology is great......when it works.

[bersaguy]

3 minutes ago, gregintenn said:

Technology is great......when it works.

So were the older cars years ago when they worked.............

[gregintenn]

Thanks to everyone who helped!

[quedz]

7 hours ago, Erik88 said:

I almost wonder if your new part was a dud. It's happened before.

WINNER WINNER...

[gregintenn]

8 hours ago, Erik88 said:

 

I almost wonder if your new part was a dud. It's happened before. I'm not sure why that ABS module would keep it from starting though.

It does appear you are correct, sir!

[Sunfish]

If the module was never flashed it will do exactly as you describe. When they have been flashed they are usually plug and play but not always. Try starting it and then reconnect the module to see if your ECM will learn it. Even then it may take several key cycles to put the ABS light out. 

Edited September 2, 2019 by Sunfish

[gregintenn]

58 minutes ago, Sunfish said:

If the module was never flashed it will do exactly as you describe. When they have been flashed they are usually plug and play but not always. Try starting it and then reconnect the module to see if your ECM will learn it. Even then it may take several key cycles to put the ABS light out. 

I'm scared I'll burn up something expensive if I plug it in with the truck running. You don't think it'll hurt anything, like burning out the BCM? If that would work, I can turn the light off with my code scanner.

 

I've been emailing back and forth with the seller I bought this thing from. So far they've just asked for information. It is Sunday night. I'm surprised they responded. Hopefully I'll get a resolution from them.

Edited September 2, 2019 by gregintenn

[Erik88]

1 hour ago, gregintenn said:

It does appear you are correct, sir!

Interesting. Still odd that this would keep it from starting. While it's not the same as the module, I actually removed both ABS fuses from my truck.