Fun Electrical Problem: Dead ECM?

[GP1138]

Just call around to junkyards and battery shops asking about used batteries. Usually you can get a decent one for around $20-$25. I picked up one used for our old Malibu that lasted all winter without a jumpstart and still started the car 100% when used for the first time.

[19Cutlass94]

Kenny can you get the car to my house ( delhi or albany ) this weekend? If so we can fix it no problem.

[mra32]

it looks like you have this figured out. I was gonna refer you to the thread I made about my dead ECM.

[ns87]

Kenny can you get the car to my house ( delhi or albany ) this weekend? If so we can fix it no problem.

 

Hey thanks for the offer. I believe it is fixed.

 

The car started after sitting overnight so this is a good sign. I chose the route which may not be best for the alternator (but I have a lifetime warranty on it ), and just drove this car a lot today to get the battery charged.

 

After driving all day, it never stalled or threw any lights what so ever! I checked the battery with my volt meter. I couldn't remember if it was AC or DC, so I read both just incase.

 

AC-13

DC-17 which according to the chart on my meter means the low end of "GOOD"

 

I'm going to keep my eye on the battery, but I have a feeling that old computer is what drained it. Before I replaced the computer the car kept clicking all the relays on and off even when the key is out of the ignition

 

I think I will switch over the PROMs this weekend. Everything is fine except my Speedo, which reads between 10-15mph SLOWER than it should One problem at a time.....

 

Thank you everyone for the help. I just need this car to last another year or so. I don't think it even wants to live that long

[Addicted To Boost]

You should use Volts DC to check battery voltage. If you're getting 17 VDC at your battery, something is wrong!

[RobertISaar]

yeah, the alt should regulate it down to around 14.7-15 with no/small load, right?

[Crazy K]

was the battery checked while the car was running?????

[RobertISaar]

was the battery checked while the car was running?????

 

at 17volts i would hope so... then again i have seen 16volt batteries, i guess they would sit at around 17 volts even when fairly discharged

[ns87]

I'm no master of the multi-meter. It has too many settings, and it's one of the old style ones with the needle.

 

I will double check this tomorrow. For all I know, I had it on the wrong setting or mixed up the numbers. It was done without the car running

[RobertISaar]

post a pic and we'll walk you through it...

[jtwmechanic]

it would probally be alot simpler for you to stop by an autozone or something and let them check it,they won't charge you a dime. are you sure you have a multi-meter and not a dwell-meter? you can check for "DC" voltage with both!

[19Cutlass94]

Kenny can you stop up at delhi at all? or if you have some free time gimme a call and ill run over to oneonta.

[ns87]

Well, rainy day here. And my car stopped working again

 

I tried to make a video with my camera phone, but it isn't too good. When the check engine comes on, the rpms dip a bit and immediately the low coolant sensor comes on too (can't see in video).

 

Also, sometimes when I give it gas, the RPMS actually dip before rising.

 

I was on the way to get the battery tested when the car completely died. Maybe tomorrow? Any ideas other than battery? I'm going to clean the low coolant sensor, but I don't think that will do much.

 

[19Cutlass94]

i wouldnt even bother trying to clean it. Just replace it since you have it out. But is there a place you can go to get it scanned for free or on the cheap side to see what cose its been throwing?

[ns87]

i wouldnt even bother trying to clean it. Just replace it since you have it out. But is there a place you can go to get it scanned for free or on the cheap side to see what cose its been throwing?

 

I can check the code with the paper clip. I've been meaning to, its just school has been really hectic this week. I'm going to bring the battery to Advanced Auto as soon as the school work dies down. Then I'll take it from there. I'll try to text you tonight, sorry I'm not good about that.

[ns87]

I'm kind of at a loss for this one. It won't give me any check engine codes. And like the old computer, now the check engine and low coolant lights won't light up.

 

I switched with the old ECm, and sure enough same symptoms.

 

Again, it won't give me any check engine codes. I have fuel (but the fuel pump only primes when I stop cranking, not when it's on the ON position). I also have spark. Any ideas? I'm not even going to deal with the low coolant light bc it really has nothing to do with how the car runs

[Doc]

Have you had the battery checked. I had this happen a couple of times were I have lost a connection inside the battery plates. Mainly on the nagitive side.

[ns87]

Have you had the battery checked. I had this happen a couple of times were I have lost a connection inside the battery plates. Mainly on the nagitive side.

 

Well, I'm not gonna get my hopes up but Advanced Auto said it tested bad. I'm pretty sure this is the problem, but everytime I say that I wind up replacing another part I'll keep you guys posted

[Hairdo12]

Get the car running, turn on the headlights, put the heater fan on high and turn on the rear defrost. See what happens with that kind of load on the electrical system.

 

[ns87]

Get the car running, turn on the headlights, put the heater fan on high and turn on the rear defrost. See what happens with that kind of load on the electrical system.

 

 

Well thanks to Advance auto for wasting my time. They tested my battery and said it's "definitely bad". I convinced a friend to drive me an hour away to get a new battery under warranty from Autozone. Car STILL won't run. The check engine light doesn't come on, I can't check codes, and the fuel pump won't prime.

 

It's definitely a wire somewhere. At one point I briefly had The check engine light and low coolant light flickering. I've checked all fuses, the fuel pump relay, and all the connections going to the major sensors.

 

I'm out of ideas. Pretty much ready to get rid of the car. Almost any shop I bring it to won't be able to figure this out, I know it. Here's how I imagine the conversation:

 

Shop:"Oh yeah, it's the computer"

Me:"No, I just replaced that"

Shop:"Gotta be the alternator"

Me:"just replaced it"

Shop:"bad battery can lead to all sorts of weird things"

Me:"just replaced it"

Shop:"ohh, your fuel pump is bad"

Me:"2 years old"

Shop:"fuel pressure regulator, it's not getting fuel"

Me:"No. Just replaced that. Something electrical doesn't tell the car to prime the fuel pump"

Shop: "Oh, coil packs"

Me: "Just placed this summer"

Shop: "ICM will cause it not to start"

Me: "No, if you checked you'd see I have spark. Also just replaced this summer"

 

[RobertISaar]

electrical issues are a bitch, huh? for all of our understanding of nuclear type stuff, the average person has no idea how to find out whats wrong with their car...

[Crazy K]

trade your problems for a large box of pizza rolls????

 

 

[ns87]

trade your problems for a large box of pizza rolls????

 

To be honest, my car has one more shot at a repair shop. I'll be very specific with them , and if they can't figure it out I'll probably sell it (READ CHEAP) to anyone on this forum. We'll see.

[RobertISaar]

new york is too far for me but i would love to have a cutlass

[ns87]

Well I consulted my handy Shop manual. It told me if the check engine light doesn't appear, to test the 2 power wires TO the ecm. Both had voltage. I also checked another power wire, and that had voltage.

 

It then said, if those checked out, check the ecm grounds. I checked the grounds, and they all had resistance (lower number is good in this case right)? Does this mean my second junkyard ecm died just like my first????? If that's the case, I'd like to know what is causing it.

 

If both of those check out, the flow chart says "REPLACE ECM"

Any ideas?