Over the past week a major issue started happening to me randomly. Its already happened to me 5 times all on the freeway and unfortunately where there is no shoulder. One day it hit me 3 times. Any help would be much appreciated

Situation:
Cruising 70mph in-gear then sudden loss of all electronics (fan, cluster, wipers, power steering), unresponsive throttle, and seems like the spark plugs stopped firing the way the engine winds down.

Hazards still work and I stop in the far lane. Pull the key out of the ignition, key back in into "on" position but nothing turns on. Take the key back out wait about a minute and try it again everything starts up fine and back to normal.

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Thoughts:
Can't be the battery because everything starts up fine after just takes about a minute. Can't be the alternator because then the battery would be dead. Figure it could be an electronics short circuit somewhere. Resetting the ECU seems to make it go away for a while but it could just be my wishful thinking.


*update* 02/05/10

I managed to recreate it intermittently by turning everything on parked and idling: a/c, fan max, recirculate air, high/low beam, cruise control, radio full blast, wiper max. I was also able to stall the engine a couple of times by hitting left turn signal. As soon as I hit it, motor would die, cluster, out windshield wipers out BUT headlights and radio would stay on. It would stay that way for about a minute before I can get the cluster to turn on again.

 

is it a sudden loss "smooth" or is it a jerky-stop?

if tis smooth, its electrical, if its jerky its fuel related.

sounds like its "smooth" the way you describe it....when it happens, do you hit a bump? (i.e loose ground getting thrown around?)

any funny sounds while it dies?

 

Its smooth so I agree with you most likely electrical. I can't isolate any specific road related cause but when it does happen it occurs under smooth road conditions so no bumps.

No funny sounds when it dies just a muted lower sound volume from the motor. Another thing I'm curious about is if the engine would take damage because I'm pretty sure the spark plugs aren't firing and also I kept it in gear until I rolled to a stop, didn't want to find out the hard way if my brakes went out as well.

 

Power loss can still be smooth if its fuel related... Loss of fuel pressure would do, this for example if your fuel pressure regulator would go out. But I do agree that it is most likely electrical.

 

check out your ignition switch. Sit in your car with the vehicle running and see if by wiggling the key
you can make the vehicle shut off.

 

from my previous experiences, if its fuel related, even if its the FPR the remaining pressure causes some mean hesitations/skips/jumps (ever had a tank of gas run dry?)

Probably not the end all way of determining whats wrong but most of the time its true..

Assuming your battery is good with no dead/dying cells, I'd really start with simple stuff first:

1) Battery grounds
2) fuse panels...make sure theres no rust falling into them/no metal/shorts/corrosion...
3)??
4) Swap ECU's with someone??


keeping it in gear wont damage a thing - the oil pump is working off the engine spinning so its still getting oil, just no spark. You're right about the brakes though - dont EVER pump the brakes after this happens, you'll lose vacuum boost (which helps you stop) and your brakes will be pretty useless. Keeping it in gear will help you keep vacuum going (slightly) so keep it in gear, roll to a stop, apply brakes ONCE or twice at the most.

Hm, I take that back about the grounding issue if your hazards still work...are they on strong? or really weak..take a peek next time. If its on very faintly it could still be a battery issue - hazards dont really need 12V to turn on...

Leaning towards ECU but hopeful its battery.. the things you mentioned not working: i.e. wipers, fan takes lots of power but the radio and cluster dont..

--edit

forgot about ignition switch as the guy above me mentions.. sounds reasonable!

 

+1

Disagree with the fuel related diagnosis because the cluster and the rest of it turns off. The symptoms are the same as someone turning off the car.

OP - do you have alot of heavy crap on your keychain?

 

Do you have an aftermarket alarm?

I had an alarm installed and experienced exactly what you are describing. It was a pita to figure it out, but the alarm install was the culprit.

J

 

Tried wriggling the key in the ignition but couldn't replicate the problem. I only have 3 keys and 1 remote on my keychain.

[QUOTE]Do you have an aftermarket alarm?

 

I bet this is alarm related ... it sounds very much like what I was experiencing.

I also have a Clifford, and at some point in the wiring mess there are like 4 or 5 relays all bunch up together. One of the but connectors on one of the relays was not tight. I really cant describe it too well ... but I was just check out all the alarm relays and the brain itself and make sure its all plugged in properly.

J