Fun Electrical Problem: Dead ECM?

[ns87]

 

Does this mean the wire going from the fuse block to the battery is bad? Or is that fuse/fuel pump relay block bad?

[Crazy K]

wait... how are you getting the measurement?

 

 

are you going from the positive of the battery to each of the points you probed?

[Brian P]

if you're not getting 12V to at least 1 terminal of that fuse socket, it's something in or under the underhood fuse block that went bad.

[ns87]

wait... how are you getting the measurement?

 

I mimicked whatever wire I was testing.

 

Those little bars I drew show where I put my multi-meter. So for the one furthest left, I did between + Batt and the first part of the fuse block.

 

The middle one I mimicked a fuse (not the best idea I know).

 

The last one, was between D17 and end of fuse; C1 and end of fuse

 

if you're not getting 12V to at least 1 terminal of that fuse socket, it's something in or under the underhood fuse block that went bad.

 

Ok. So tomorrow, I will unbolt that sucker from the shock tower and see if I find anything of interest. Other than lucking out and finding a broken wire.....Are those known for going bad at all? Or is there a specific point I could clean besides the AUX post?

 

I will disconnect the wire that runs from the + battery post, and OHM test that as well.

 

Thanks everyone! any other ideas are appreciated

[Brian P]

yeah, the wire could have corroded off the fuse terminal (I think it's just crimped). Did you test for voltage with the + probe on each terminal, with the - probe touching chassis ground?

[ns87]

yeah, the wire could have corroded off the fuse terminal (I think it's just crimped). Did you test for voltage with the + probe on each terminal, with the - probe touching chassis ground?

 

I think I did, and got negative infinity. But I will double check that tomorrow

[ns87]

if you're not getting 12V to at least 1 terminal of that fuse socket, it's something in or under the underhood fuse block that went bad.

 

+ post to first terminal of fuse. 13.5V

 

ECM pinout(s) to second terminal: Infinity ohms, 1V

 

I ran two wires from the second terminal to the pinouts.

 

ECM pinout(s) to second terminal: 0 omhs, 13.5V

 

STILL EXACTLY THE SAME NO START SYMPTOM.

 

I have two computers I've tested (one is brand new).

 

So is it the memcal?

 

[mra32]

you want me to send you the memcal out of the 3.1 grand prix i got from the j/y (free of charge)? not sure what transmission it had. I might have tossed it. Let me know if you want me to look for it.

[mra32]

have it, took 10 seconds to find. let me know

[Crazy K]

it is too unlikely that the chip you are offering will not work.

 

 

but...

 

 

i think I have the correct chip (since I have like 50). I will need to know all coding on your memcal to check. Look at the silver sticker, if the replacement does not match, it might not run.

 

if worst comes to worst, I can try to locate the properly coded chip.

[mra32]

Well for the record the one i have is as follows

 

On the outside it is:

 

BFBB

0192

 

On the inside it is:

 

9733

3126

 

and then there is this on the potted chip:

 

1093122

[RobertISaar]

Well for the record the one i have is as follows

 

On the outside it is:

 

BFBB

0192

 

On the inside it is:

 

9733

3126

 

and then there is this on the potted chip:

 

1093122

 

BFBB:

91 w-body with 3.1 and 3 speed

[ns87]

Ok. My car is parked 3 blocks from my APT, so tomorrow I will check on that code. Ken, if you have any potential ones in mind, could you get them on hand tonight? I'll paypal you some $$$ to get one or two to me ASAP

 

have it, took 10 seconds to find. let me know

I don't think that one will work, but thank you very much for the offer

[RobertISaar]

if someone either PMs me the BCCs or posts them here i can decode them...

[Crazy K]

Ok. My car is parked 3 blocks from my APT, so tomorrow I will check on that code. Ken, if you have any potential ones in mind, could you get them on hand tonight? I'll paypal you some $$$ to get one or two to me ASAP

 

have it, took 10 seconds to find. let me know

I don't think that one will work, but thank you very much for the offer

 

ok. I have them at hand already. worst case scenario, I will probably go to the j/y on monday.

[ns87]

Before I get too hopeful about this memcal thing, does anyone else have any ideas???

 

Just to recap.

 

The two power wires to the ECM were broken somewhere. They had no resistance from end to end. I ran my own power wires from the fuel pump relay fuse to the ECM connection. The wires now have resistance, and I can measure 12 volts at the ECM end (previously there was less than 1).

 

My car still acts like no ecm is plugged in. The fuel pump won't prime, the check engine light won't come on, and neither does the low coolant light

[Crazy K]

Before I get too hopeful about this memcal thing, does anyone else have any ideas???

 

Just to recap.

 

The two power wires to the ECM were broken somewhere. They had no resistance from end to end. I ran my own power wires from the fuel pump relay fuse to the ECM connection. The wires now have resistance, and I can measure 12 volts at the ECM end (previously there was less than 1).

 

My car still acts like no ecm is plugged in. The fuel pump won't prime, the check engine light won't come on, and neither does the low coolant light

could the new computer be fried already?

[Brian P]

if you're not getting 12V to at least 1 terminal of that fuse socket, it's something in or under the underhood fuse block that went bad.

 

+ post to first terminal of fuse. 13.5V

 

ECM pinout(s) to second terminal: Infinity ohms, 1V

 

I ran two wires from the second terminal to the pinouts.

 

ECM pinout(s) to second terminal: 0 omhs, 13.5V

 

STILL EXACTLY THE SAME NO START SYMPTOM.

 

I have two computers I've tested (one is brand new).

 

So is it the memcal?

 

 

 

One thing that comes to mind is that if that wire is bad, is the fuel pump getting power at all? It depends on where the power wires had failed. Do you get power at pin #4 of the fuel pump relay?

 

I hope the ECM didn't get fried from all these problems and tests, but it's a possibility.

[Brian P]

also, all grounds are good at pins D4, D10, D12, and C6? pg 6E3-A-5

[ns87]

also, all grounds are good at pins D4, D10, D12, and C6? pg 6E3-A-5

 

I'm not seeing a D10 anywhere. Do you mean C10? I will check D12, D4, and C6 tomorrow. Speaking of D4....wtf is a "Peak & hold"?

 

One thing that comes to mind is that if that wire is bad, is the fuel pump getting power at all? It depends on where the power wires had failed. Do you get power at pin #4 of the fuel pump relay?

 

I hope the ECM didn't get fried from all these problems and tests, but it's a possibility.

 

The fuel pump primes when I use that "tester wire" to the postive terminal of the battery. I can check pin#4 for power tomorrow. Would I put the ground part of my multimeter to any ground point on the car?

 

Thank you again everybody, and keep the suggestions flowing! I have some time this weekend to try stuff out

[Brian P]

also, all grounds are good at pins D4, D10, D12, and C6? pg 6E3-A-5

 

I'm not seeing a D10 anywhere. Do you mean C10? I will check D12, D4, and C6 tomorrow. Speaking of D4....wtf is a "Peak & hold"?

 

I remember reading D10 but it could always be a misprint, or I saw double vision (it was late). Those wires *should* be true grounds, meaning they are grounded to a screw on the chassis (supposedly near the ECM mounting area but I dunno). In that case you can do either a continuity check between the wires and chassis, or stick the + lead of your multi onto any +12V source, the - lead on the ground pins and see if you can read +12V. I prefer to test power and ground sources in this manner over continuity checks. I usually reserve continuity tests for unpowered circuits.

 

 

 

 

The fuel pump primes when I use that "tester wire" to the postive terminal of the battery. I can check pin#4 for power tomorrow. Would I put the ground part of my multimeter to any ground point on the car?

 

 

Yeah, that will work. You could also stick the - multi probe onto the ground pin of the relay socket (should be on the same page)

 

[ns87]

Decided to look for corrosion on the bottom part of the aux post (where the relay wires are connected). I instantly dropped that nut, and it's now gone forever in my engine bay.

 

I'm going to the hardware store to see if I can find one that will fit, then I will try these tests.

 

CrazyK:

 

J733

1249

6J0032

[Crazy K]

Decided to look for corrosion on the bottom part of the aux post (where the relay wires are connected). I instantly dropped that nut, and it's now gone forever in my engine bay.

 

I'm going to the hardware store to see if I can find one that will fit, then I will try these tests.

 

CrazyK:

 

J733

1249

6J0032

is there more info? usually there as a 4 digit letter code like ABUD or BKDD did you look for a sticker hidden in the window?

[ns87]

I'll take another look later this afternoon. Sorry for the delay, but its a 3 block walk to my car back and forth, and I'd like to eat some lunch