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Bad -CPU?-

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Old 01-10-06 | 12:20 PM
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Tech_Greek's Avatar
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Rockn' The Galant

 
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Bad -CPU?-

Well, I was reading through my new found Haynes Manual and it lists the CPU does functions such as "ding" when the doors are open, turn the keylight on by the key when you open the door, etc.

The problem is, half the stuff it lists, my car DOESNT do, and is supposed to...tall tall sign of a bad CPU? Could this have something to do with my head lights not goign down?

I looked at the CPU, theres no signs of rust or anything like that but I guess anything is possible.

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Old 01-10-06 | 12:28 PM
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there are too many other factors involved in those little things not working to just say its a bad CPU.......
for example:

no key light? - bulb? bad wire?
no ding when doors open? - bad indicating switch? bad connection?poor ground?

see where im going with this?
Old 01-10-06 | 12:31 PM
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Checked all those little things, turned the bulb on without it hooked up to the harness with a simple power/ground and it lit up fine.

I don't see why the switch would be bad, I puled it out and it looekd fine.

Grounds are good, I've pretty much checked everything there is to check there, I get no hesitations throughout the RPM range or any signs of a bad grounding system.

Also my security system doesnt work, the lights wont go into bright mode (albeit I tried them in my dads rx7 adn they worked fine)...etc

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Old 01-10-06 | 01:01 PM
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So, the key lights don't work and the highbeams don't work and the security doesn't work... does the dome light work???

All the plugs are plugged into the CPU right???
Old 01-10-06 | 01:21 PM
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Rockn' The Galant

 
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Yep...that's what I'm saying, I seriously think the CPU is bad.
Old 01-10-06 | 01:34 PM
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well if youve checked all those little things then its possible.

I was merely pointing out ( because alot of people make the leap) that just because something the CPU controls doesn't work.......doens't mean the cpu is bad

its entirely possible you might have cold solder joints if you have checked all those other little things
Old 01-10-06 | 01:48 PM
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Rockn' The Galant

 
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Oh defintley, my car has more electrical gremlins than you could possibly imagine.

1) The wipers only work on one speed, suspected to be the switch of course.
2) The head lights WONT go down, but up, with the siwtch plugged in (tried about five different things)
3) The AAS doesn't work with the original AAS struts on, looked in the back the box has rust on it so I know its shot.
4) The bright lights dont work.
5) The key light doesnt work.
6) No buzzers what so ever. (OH when I was out of coolant via a hose failure it did thank god)
7) Driver Side Seat Belt As. wont work even tried a different one.
etc
etc

I've looked at the wiring, it looks better than any car I've ever seen and clena and intact, no signs of a short or anything like that via my volt meter..
Old 01-10-06 | 02:47 PM
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1) The dinky relay in the wiper switch wears out every 15 years.
2) Check the harness-to-switch plug for tight clean shinny metal-to-metal contact.
3) Remove the AAS, hand turn the struts to firm & just leave them there. (My old GXL gave a pretty good ride on 12 year old shocks set that way.)
4) That could be the switch or the relay up front.
5 & 6) The solder joints that join the CPU board to its connector pins like to crack. Resolder the connector pins to the board.
7) Need more info.
Old 01-10-06 | 02:48 PM
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Originally Posted by Tech_Greek
Oh defintley, my car has more electrical gremlins than you could possibly imagine.

1) The wipers only work on one speed, suspected to be the switch of course.
Bad wiper switch, get a rebuilt one from Icemark
2) The head lights WONT go down, but up, with the siwtch plugged in (tried about five different things)
have you tried a different switch???
3) The AAS doesn't work with the original AAS struts on, looked in the back the box has rust on it so I know its shot.
Could be unplugged switch or a blown fuse as well
4) The bright lights dont work.
bad dimmer relay
5) The key light doesnt work.
does the door key ight light up??? if it does but the ignition key light does not, then you probably just have a burnt out bulb
6) No buzzers what so ever. (OH when I was out of coolant via a hose failure it did thank god)
the CPU only buzzes with the lights on or the key in the ignition and the door open, anything else is a differnt buzzer.
7) Driver Side Seat Belt As. wont work even tried a different one.
etc
etc
bad switch in the seat belt assem,bly
Old 01-10-06 | 10:52 PM
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Rockn' The Galant

 
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From: Shreveport, LA
Originally Posted by Ronin Rotary
Bad wiper switch, get a rebuilt one from Icemark
Planned on it...

have you tried a different switch???
Does 10 different ones count?

Could be unplugged switch or a blown fuse as well
Check them all with a volt meter, all are fine.

bad dimmer relay
Ok

does the door key ight light up??? if it does but the ignition key light does not, then you probably just have a burnt out bulb
Nope, neither do, already replaced bulb with a brand new one.

the CPU only buzzes with the lights on or the key in the ignition and the door open, anything else is a differnt buzzer.
It never buzzes

bad switch in the seat belt assem,bly
Where's it at? Also my passenger side is slow to respond, unless you close the door and open it again then it's fine.
Old 01-10-06 | 11:01 PM
  #11  
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No, I meant that more than half the problems you listed have nothing to do with the CPU. For example you said it didn't buzz/beep when you had low coolant, the buzzer that when off is not part of the CPU, but rather then gauges.

And if your high beams never work, then the dimmer relay is bad. Its only if the headlights don't stay on but flash just fine would it be a bad CPU.

Or the seat belts (which have their own computer).
Old 01-10-06 | 11:03 PM
  #12  
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Rockn' The Galant

 
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You misread it,

The coolant buzzer DOES work, it's the ONLY buzzer that works.

Where's the relay located at? If it's in the front header panel area than no, it's not a relay, I've tried all of them.

The seat belts have their own computers? Where are they located at?
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