Ecm Failure?

[email protected] · June 14, 2009

After my battery went dead and had to be boosted, all the dash lights are staying on in my 2003 Silverado and there is no communication with the computer for error codes. Otherwise the truck is running fine. Does this sound like an ECM failure, and what woudl cause it?

Thanks

superjim · June 14, 2009

If it was ECM..(Engine Control Module)..that failed, I don't think truck would run.

Sounds more like the BCM..(Body Control Module)..or the IPC..(Instrument Panel Computer).

Take "BOTH" battery cables off.

Briefly touch them together to drain/discharge all capacitors.

Reinstall both cables to battery.

If something is not fried, maybe just confused, this may straighten it out.

redvett · June 14, 2009

If the ign was on when you jump started it the BCM is probably bad.

deadringer · June 14, 2009

I would agree that you should try "rebooting" truck by disconnecting the battery... I had issues with my RDLCM where it wouldn't unlock but had no troubling locking... rebooting fix the problem.

VMax2007 · June 14, 2009

If the ign was on when you jump started it the BCM is probably bad.

How do you jump start it without turning the ignition on?

txab · June 14, 2009

I would agree that you should try "rebooting" truck by disconnecting the battery... I had issues with my RDLCM where it wouldn't unlock but had no troubling locking... rebooting fix the problem.

+1

Also, if your unable to read codes at the OBD port, check cigarette lighter for proper operation. if it doesn't work check for a blown fuse

2005LT · June 14, 2009

If the ign was on when you jump started it the BCM is probably bad.

How do you jump start it without turning the ignition on?

+1

redvett · June 14, 2009

If you leave the ign in the on position and jump the vehicle the quad drivers will be permantly damaged. Always have ign off when ataching the jumper cables.

If the ign was on when you jump started it the BCM is probably bad.

How do you jump start it without turning the ignition on?

+1

VMax2007 · June 14, 2009

If you leave the ign in the on position and jump the vehicle the quad drivers will be permantly

Thanks for clearing that up.

So, question for you. I used to know this, but it had been years since I have jump started another vehicle or needed a jump start. The other day I had to jump start my wife's car. I could not recall the proper sequence for attaching the cables. neg or pos first? dead or donor car first, etc?

What is the proper sequence/procedure for attaching cables?

Z45 · June 14, 2009

Attach POS cables first to dead bat and then to donor bat. Install NEG cable to dead battery and lastly the NEG to NEG ground of the vehicle being used. NEVER install POS cable last, it will Arc and could cause battery gases to explode. When the vehicle starts, remove NEG cable first.

Never allow vehicle or cables to touch and always protect your eyes when connecting battery cables.

As has been noted here, jump starting can fry electronic equipment if not done properly. Make sure any accessory is turned off.

VMax2007 · June 14, 2009

Attach POS cables first to dead bat and then to donor bat. Install NEG cable to dead battery and lastly the NEG to NEG ground of the vehicle being used. NEVER install POS cable last, it will Arc and could cause battery gases to explode.

Never allow vehicle or cables to touch and always protect your eyes when connecting battery cables.

As has been noted here, jump starting can fry electronic equipment if not done properly. Make sure any accessory is turned off.

Thanks!

2005LT · June 14, 2009

Yeah, thanks Mike. That was a good explanation.

brims · June 14, 2009

Attach POS cables first to dead bat and then to donor bat. Install NEG cable to dead battery and lastly the NEG to NEG ground of the vehicle being used. NEVER install POS cable last, it will Arc and could cause battery gases to explode. When the vehicle starts, remove NEG cable first.

Never allow vehicle or cables to touch and always protect your eyes when connecting battery cables.

As has been noted here, jump starting can fry electronic equipment if not done properly. Make sure any accessory is turned off.

It will arc either way when you are pulling a load. I assume you are using the positive cable to the battery and the negative to the engine block. Also the hydrogen is only being produced when recharging the battery. This is also another reason why something like a sealed AGM battery is good.

The times I've hooked up a battery, I hook the dead battery up, then hook up the donor battery. I never had a problem with that.

bill190 · June 15, 2009

Check the battery to see that it has a full charge. Should be 12 something volts with the ignition on (don't start). Use a multimeter or your dash gauge. Then should go up to around 13/14 volts after starting.

Then check the battery terminals to be sure they are clean and have good connections.

Check main ground wires to body and engine block to be sure they have a good clean tight connection.

The voltage level is very important with all these computer modules. If you get a low voltage around 9 volts, they are not happy!

Then check all fuses...

http://www.dinosaurelectronics.com/Test_Fuse.htm

Other than that, there can be up to 24 different "computer modules" in a newer vehicle running on two or three different computer "Local Area Networks". Best to have that checked at a GM dealer. They can tell with their computer testing gizmos if a certain computer module is not responding.