I need to know where the vacuum modulator is located on the car my sons put his car in park and now the trans is doing nothing worked fine right before that

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Vacuum Modulator Service.wmv - YouTube

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www.youtube.com/watch?v=u7S9mDqWguY
Dec 19, 2011 - Uploaded by GrumpysTravells How to remove and clean the vacuum modulator air filter. ...Transmission modulator replacement (early GM 4T60-E models) -

Hi Brent: I'm no mechanic but I would look for a vacuum leak. I had a old car that did this to me. Started and idled strong but you couldn't put it in gear or it would die. After weeks of various male friends looking at it one finally found the problem. Turns out it was a vacuum leak or Vacuum Modulator. I found this page online that might help... It explains how auto trans work... etc. Hope it helps.

http://www.familycar.com/transmission.htm

On the passenger side towards the back of the transmission. Vacuum modulator about 3" in diameter with a single fitting coming out of the center.

This is a common issue on '06+ Impalas, and is most frequent when parking on an incline. It can be minimized by engaging the parking brake before putting the car in Park.

Your brake light switch system controls the shift interlock system, you'll need to check that system first. Could be a shift interlock swith has gone faulty or the linkage is out of adjustment.

Check that link out, could be a solenoid issue or it could be that a wiring harness is going bad/fried:
naioa.com/v2/modules.php?stuck+park&start=0

Hope helps.

Your shifting module(netural park switch) on the trans has to line up with the mark or slot. Key on car off block wheels, put car in first and see where the module shifts and do the same for all the gears to see if they are lining up. All so check the shifting cable make sure its at the right length.

Hello and yes this is a major noise. I would check your oil now right before you ever start the oil again. This noise may have been your engine locking up from really low oil levels and excessive heat from a lot of driving. If this is fine contact me again and we will address more problems if their is more. Thank You.

Replace your blower motor relay. It's located under the hood on the firewall passenger side.

i put a 1990 allante trans into my 1988 allante, the used trans was working fine before i put it into my '88 allante. now it shifts very rough and has trouble going into park and the linkeage is very stiff.....someone told me there is a transmission control module that could be the problem or some kind of vacuum control module????any ideas???..........thanks, rodney

Hello, The adjust of your t/v cable, not kickdown cable, and the operation of the vacuum controller at the rear of injection pump, and the modulator, is critical for this car to get a good shift.
Put you cable back on, adjust it so that when you have wide open throttle, the cable does not have any slack. Check the black vacuum line by the oil filter housing that goes to the modulator to see if it has vacuum. It should have about 10-15" vacuum and as you increase engine speed it should drop. If you get close to this, the trans should shift ok. If you cannot get vacuum at the modulator line, you need to ck vacuum supply, valve at rear of injection pump, hose routing, etc.
If the B2 piston failed, it would be difficult to move car or slip badly. Also, take into mind that at the bottom of your accelerator pedal stroke is a kickdown switch.
If you accomplish what I instructed, you will probably get a decent shift.
If you find this information to be correct would you please enter a "fixya" rating.
Thanks, Gator241

I don't recall ever seeing an AOD trans behind a 2.3 ltr 4 cylinder engine,all the one's i've seen had the A4LD trans in it.That model trans utilizes a vacuum modulator that is mounted on the passenger side of the trans case.The vacuum modulator is responsible in large part for the trans upshifting at the proper speeds.I have seen plenty of cases where those modulators go bad.When this happens,late shifting is experienced,and the same thing happens if any of the vacuum lines under the hood have a problem,like cracks,small vacuum leaks,etc.To diagnose,you have to get under the car,and disconnect the vacuum line from the modulator.If the modulator is bad,trans fluid will run out.If the modulator is good,no fluid will run out.Hook a vacuum gauge to the line down at the trans,and start the engine.Idle vacuum should be 15-18 psi,and when the throttle is abruptly applied to wide open throttle,vacuum should drop to near zero.There is one other area to look for problems on this trans,still externally,and that is the servos.They are located also on the passenger side of the trans case,and there are 2 of them.They are round circular aluminum covers held in place in round bores with snap rings.They can be removed,and are black metal stampings coated in rubber.If the rubber lip seals are hardened up from the exhaust heat,replace them,and you may get your gears back.Good luck.