hey guys, recently i had my cpu changed out of my car. i believe it shorted because of my stereo. i have 2 amps.
1 alpine v10 powering my 4 speakers @ 4 ohms
1 sony xplod 400watts RMS@2ohms powering my 2 ohm 10 inch alpine type S
i had this all hooked up all pro , mounted , proper wiring etc it worked great for about6 months . i had it all tied together with my capacitor. now all of a sudden my cars electrical has a heart attack ,, my traction light abs and airbag lights come on and when i shift into gear it doesnt drop to first, it starts me out in second. sooo i had the cpu replaced as the dealership thought neccessary. while my lights acted funny is when my stereo also started sounding funny. for instance if i put on volume one all i hear is rumbling bass like a sort of static only bassy . im pretty sure the car problems and sound problems are related. anything you woudl suggest, im already 500$ in th hole from my cpu and now the fixed one does the same thing in my car and my sound is still garbled. my alpine sounds perfect but bass still is lame. the lights in my dash arent always on and when they kick on my subs cut out completely although only for a few seconds once that happens i no longer have any torque and my tranny doesnt shift right. my mechanics that ive talked to are stumped
thanks for any help u might have
Replies (10)
ryan2 on 07/23/2005 22:57:26
I dont know the solution to your problem. But I would say get your money back from the dealership. If they said its probably your ccpu and they replaced it and everythign does the same thing I wouldnt let them have my $500.
superbali on 07/23/2005 23:00:12
i have and they are going to look at it but ive been reading and i was wondering if it had something to do with my cap, perhaps its pooched
swez on 07/24/2005 10:18:05
Just a thought, disconnect the cap and sub amp for now. See if your whole cars' systems problems change or even return to normal. Make sure you remove the BAT's neg power wire. This clears the CPU of all error codes and resets CPU to factory defaults.
The symtoms mentioned, do immitate a problem with the ECM/BCM computer functions, as they monitor & control all the devices and warning lamps noted. The dealership took the easy way out by simply swapping the CPU, but the problem may be in another section of the vehicle, creating all these error codes.
May I further suggest you order a copy of the GM repair/diagnostics manual for this car. They can be ordered online or get details from your owners manual that came with the car. This is the Bible that shop mechanics often use to diagnose and test all systems and devices in your car.
Had similar problems on an Olds Trofeo' a few years back. The dealership searched it for 5 days, but could find nothing that fixed any of the problems. (they also tried a new CPU) It did not work either. Read that manual ($100.00) in great detail and finally tracked down the problem. It was the dashboard display module that was causing all the problems. Dealer wanted $1200 to remove the old unit, have it rebuilt and reinstalled. Said I'd lose the car for 2 weeks min. NOT!!!
I tracked down the Mfg., that makes the display module and got a detailed rundown on the fixes needed. Went to a local bone yard, they found one for $200.00 (in Iowa), got it in 2 days, installed it and all problems went away.
In short, the Dealerships are there to make a huge profit at your expense. Typical labor rates for this level of repairs are often close to $90.00/hr. Parts markups are equally appalling, especially when it's a dealer only part. Get the manual dealership mechanics use, study the sections related to your car issues and then make step by step tests to home in on the source of all these issues. Yes, it's time consuming. But you will keep your wallet fatter and be a wiser man for doing it yourself. Trust me, most Dealership mechanics are swap jockies, not Techs.
Swez
PS Does your dash cluster have a voltage meter on it? If so, what is the voltage range you see normally and when the car starts to mis-behave?
superbali on 07/24/2005 17:28:06
thanks alot swez, i was feeling it could be the dash too. before all of this i had minor problems with the doors locking when i never clicked the button or if i was in reverse and tapped the brake the doors would lock repeatedly for every tap on the pedal. i did disconnect the sub amp and cap and it allowed the car to not be as problematic however it still did the same thing when i left my car in idle. no i dont have a voltage meter but like i said all this worked great for at least 6 months. i was thinking it was a relay or a fuse under the hood perhaps or something inside the dash. the mechanic said since the old cpu was pooched when the diagnostic was run it may have not shown the correct codes or the actual cause of problem. youd think they would have diagnosed it after swapping my cpu. i understand my system is too demanding for my car but until now all that happend was dimming lights , none of this nonsense. i will mention on monday to the mechanic to check the dash components. anything else you would suggest? that suggestion could be warranted as i believe my brakes making the doors lock has to do with when i put my foot on the brake to go into reverse or gear, sometimes the light that shows which gear im in doesnt always work and i have one of those cars that locks the doors as soon as u put it into gear? so maybe dash modules control these things and are shorting?
swez on 07/24/2005 19:55:08
The problems noted and having a pretty decent sound system may or may not have much of a connection. The fact the system and car were fine for 6 months, seems proof of that.
I would suggest a voltage/current test on your ALT/BAT before doing anything drastic. If your ALT (regulator) is going south, iy can be measured by a voltmeter and current tests that can be done "free" at any major autoparts store.
Also, try pulling the Neg BAT line off the BAT and let the car sit a few minutes. This resets all CPU functions bact to original factory calibration values. See if that does any good as well. It may only be a temporary remedy, until the fault comes back up and the CPU resets to "Limp" mode.
Do you have an aftermarket or OEM alarm system in this car? Sometimes they can interact in ways that are not always easy to track down. It could be as simple as a bad fuse or sticky relay, or more complex.
You mentioned the tranny does not shift properly right? That can be a fault detection of a sensor (or several sensors) that sets the CPU into "Limping" mode. Enough to get you home or to a repair shop, but not enough functions to drive the car normally.
Dash lights, other functions like AC/heater blower functions and other mointoring systems in the dash can be affected by lack of adequate voltage or a damaged board in the display system. Without a detailed troubleshooting tree (usually outlined in the shop manual mentioned earlier) it is difficult to say what you really have going on here.
Dealer mechanics can see common patterns in certain cars they service frequently. However, once that plan of diagnostics are run to no avail, they RARELY pick up thier shop manual and really dig into the diagnostics tools in the manual. Too time consuming for many to bother with. They make more money swapping parts then testing various components and reading a very boring shop manual that is often very hard to understand. (until one spends a few hours reading and cross checking related circuits. Again, they get paid to do something... not learn from a book. It's often at the car owners' expense, as they "guess their way" through a problem like yours.
In short, get your electrical system tested, (ALT/BAT performance) and see if anything obvious shows up here. Low voltage output can cause many of the ills noted so far. Second, go search Google for Grand Prix websites that talk about troubleshooting their cars and possible fixes. This may be more common an issue then you might think. Third, if all else fails, get a complete GM repair manual for that model car and read it carefully before diving in to various tests on in the troubleshooting/diagnostics sections.
It took me 2 weeks to to nail the main culprit . (dash control board had weak electrolytic capacitors) But when all was said and done correctly, that Bible saved me hundreds of dollars in parts and mechanics guessing games. It was well worth the cost in $$$'s and time reading to fix other issues later that crop up in older cars.
Hope that helps,
Swez
superbali on 07/28/2005 21:16:24
ok i had the alternator replaced as it died yesterday, so far my car runs great--no wierd stuff at all but i still get a "thud" when i turn on the stereo any ideas?
Victor on 07/29/2005 01:41:36
Seems to be Grounding Issues ..
Read this..
http://www.clubknowledge.com/Car_Audio_FAQ/?t4
Check the Hu, and Amp grounds.. should solve your problems i guess..
swez on 07/29/2005 09:24:03
Good, one major issue resolved... ALT was dying and created such problems. Take the dealership to task on the new CPU they installed. It was obviously not the problem.
FYI: If you paid by credit card, dispute the charges and let card company investigate your situation. They have more clout than you do at this point. I would press to get this new one at dealership cost and no labor as it was not the culprit. If you paid by check, may be able to go to your bank and request stopping that check until issues are resolved with the dealership.
Thumps at turn on, if that was not an issue before, hard to say what is causing it now. Re-grounding the HU and amps may help.
Good luck on all points,
Swez
superbali on 07/29/2005 12:07:35
thanks dudes ur awesome
swez on 07/31/2005 10:08:24
Good luck on your cage match with the Dealership. The only way to fight them well, is with your wallet.
Swez
1 alpine v10 powering my 4 speakers @ 4 ohms
1 sony xplod 400watts RMS@2ohms powering my 2 ohm 10 inch alpine type S
i had this all hooked up all pro , mounted , proper wiring etc it worked great for about6 months . i had it all tied together with my capacitor. now all of a sudden my cars electrical has a heart attack ,, my traction light abs and airbag lights come on and when i shift into gear it doesnt drop to first, it starts me out in second. sooo i had the cpu replaced as the dealership thought neccessary. while my lights acted funny is when my stereo also started sounding funny. for instance if i put on volume one all i hear is rumbling bass like a sort of static only bassy . im pretty sure the car problems and sound problems are related. anything you woudl suggest, im already 500$ in th hole from my cpu and now the fixed one does the same thing in my car and my sound is still garbled. my alpine sounds perfect but bass still is lame. the lights in my dash arent always on and when they kick on my subs cut out completely although only for a few seconds once that happens i no longer have any torque and my tranny doesnt shift right. my mechanics that ive talked to are stumped
thanks for any help u might have
Replies (10)
ryan2 on 07/23/2005 22:57:26
I dont know the solution to your problem. But I would say get your money back from the dealership. If they said its probably your ccpu and they replaced it and everythign does the same thing I wouldnt let them have my $500.
superbali on 07/23/2005 23:00:12
i have and they are going to look at it but ive been reading and i was wondering if it had something to do with my cap, perhaps its pooched
swez on 07/24/2005 10:18:05
Just a thought, disconnect the cap and sub amp for now. See if your whole cars' systems problems change or even return to normal. Make sure you remove the BAT's neg power wire. This clears the CPU of all error codes and resets CPU to factory defaults.
The symtoms mentioned, do immitate a problem with the ECM/BCM computer functions, as they monitor & control all the devices and warning lamps noted. The dealership took the easy way out by simply swapping the CPU, but the problem may be in another section of the vehicle, creating all these error codes.
May I further suggest you order a copy of the GM repair/diagnostics manual for this car. They can be ordered online or get details from your owners manual that came with the car. This is the Bible that shop mechanics often use to diagnose and test all systems and devices in your car.
Had similar problems on an Olds Trofeo' a few years back. The dealership searched it for 5 days, but could find nothing that fixed any of the problems. (they also tried a new CPU) It did not work either. Read that manual ($100.00) in great detail and finally tracked down the problem. It was the dashboard display module that was causing all the problems. Dealer wanted $1200 to remove the old unit, have it rebuilt and reinstalled. Said I'd lose the car for 2 weeks min. NOT!!!
I tracked down the Mfg., that makes the display module and got a detailed rundown on the fixes needed. Went to a local bone yard, they found one for $200.00 (in Iowa), got it in 2 days, installed it and all problems went away.
In short, the Dealerships are there to make a huge profit at your expense. Typical labor rates for this level of repairs are often close to $90.00/hr. Parts markups are equally appalling, especially when it's a dealer only part. Get the manual dealership mechanics use, study the sections related to your car issues and then make step by step tests to home in on the source of all these issues. Yes, it's time consuming. But you will keep your wallet fatter and be a wiser man for doing it yourself. Trust me, most Dealership mechanics are swap jockies, not Techs.
Swez
PS Does your dash cluster have a voltage meter on it? If so, what is the voltage range you see normally and when the car starts to mis-behave?
superbali on 07/24/2005 17:28:06
thanks alot swez, i was feeling it could be the dash too. before all of this i had minor problems with the doors locking when i never clicked the button or if i was in reverse and tapped the brake the doors would lock repeatedly for every tap on the pedal. i did disconnect the sub amp and cap and it allowed the car to not be as problematic however it still did the same thing when i left my car in idle. no i dont have a voltage meter but like i said all this worked great for at least 6 months. i was thinking it was a relay or a fuse under the hood perhaps or something inside the dash. the mechanic said since the old cpu was pooched when the diagnostic was run it may have not shown the correct codes or the actual cause of problem. youd think they would have diagnosed it after swapping my cpu. i understand my system is too demanding for my car but until now all that happend was dimming lights , none of this nonsense. i will mention on monday to the mechanic to check the dash components. anything else you would suggest? that suggestion could be warranted as i believe my brakes making the doors lock has to do with when i put my foot on the brake to go into reverse or gear, sometimes the light that shows which gear im in doesnt always work and i have one of those cars that locks the doors as soon as u put it into gear? so maybe dash modules control these things and are shorting?
swez on 07/24/2005 19:55:08
The problems noted and having a pretty decent sound system may or may not have much of a connection. The fact the system and car were fine for 6 months, seems proof of that.
I would suggest a voltage/current test on your ALT/BAT before doing anything drastic. If your ALT (regulator) is going south, iy can be measured by a voltmeter and current tests that can be done "free" at any major autoparts store.
Also, try pulling the Neg BAT line off the BAT and let the car sit a few minutes. This resets all CPU functions bact to original factory calibration values. See if that does any good as well. It may only be a temporary remedy, until the fault comes back up and the CPU resets to "Limp" mode.
Do you have an aftermarket or OEM alarm system in this car? Sometimes they can interact in ways that are not always easy to track down. It could be as simple as a bad fuse or sticky relay, or more complex.
You mentioned the tranny does not shift properly right? That can be a fault detection of a sensor (or several sensors) that sets the CPU into "Limping" mode. Enough to get you home or to a repair shop, but not enough functions to drive the car normally.
Dash lights, other functions like AC/heater blower functions and other mointoring systems in the dash can be affected by lack of adequate voltage or a damaged board in the display system. Without a detailed troubleshooting tree (usually outlined in the shop manual mentioned earlier) it is difficult to say what you really have going on here.
Dealer mechanics can see common patterns in certain cars they service frequently. However, once that plan of diagnostics are run to no avail, they RARELY pick up thier shop manual and really dig into the diagnostics tools in the manual. Too time consuming for many to bother with. They make more money swapping parts then testing various components and reading a very boring shop manual that is often very hard to understand. (until one spends a few hours reading and cross checking related circuits. Again, they get paid to do something... not learn from a book. It's often at the car owners' expense, as they "guess their way" through a problem like yours.
In short, get your electrical system tested, (ALT/BAT performance) and see if anything obvious shows up here. Low voltage output can cause many of the ills noted so far. Second, go search Google for Grand Prix websites that talk about troubleshooting their cars and possible fixes. This may be more common an issue then you might think. Third, if all else fails, get a complete GM repair manual for that model car and read it carefully before diving in to various tests on in the troubleshooting/diagnostics sections.
It took me 2 weeks to to nail the main culprit . (dash control board had weak electrolytic capacitors) But when all was said and done correctly, that Bible saved me hundreds of dollars in parts and mechanics guessing games. It was well worth the cost in $$$'s and time reading to fix other issues later that crop up in older cars.
Hope that helps,
Swez
superbali on 07/28/2005 21:16:24
ok i had the alternator replaced as it died yesterday, so far my car runs great--no wierd stuff at all but i still get a "thud" when i turn on the stereo any ideas?
Victor on 07/29/2005 01:41:36
Seems to be Grounding Issues ..
Read this..
http://www.clubknowledge.com/Car_Audio_FAQ/?t4
Check the Hu, and Amp grounds.. should solve your problems i guess..
swez on 07/29/2005 09:24:03
Good, one major issue resolved... ALT was dying and created such problems. Take the dealership to task on the new CPU they installed. It was obviously not the problem.
FYI: If you paid by credit card, dispute the charges and let card company investigate your situation. They have more clout than you do at this point. I would press to get this new one at dealership cost and no labor as it was not the culprit. If you paid by check, may be able to go to your bank and request stopping that check until issues are resolved with the dealership.
Thumps at turn on, if that was not an issue before, hard to say what is causing it now. Re-grounding the HU and amps may help.
Good luck on all points,
Swez
superbali on 07/29/2005 12:07:35
thanks dudes ur awesome
swez on 07/31/2005 10:08:24
Good luck on your cage match with the Dealership. The only way to fight them well, is with your wallet.
Swez
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