Need Help Asap

[ALERO81]

Well I thought I would post a new thread old thread is getting really full !
For those who are just reading these are my issues
1999 Olds Alero V6

My car has been shifting hard into gears this all start 1 day after I hit a rain puddle killed the car after about 30 mins car started drove fine all the way home the next day the trouble stated ...

took the car to a transmission shop and got these codes
P0121=TP SENSOR PROBLEM
P0730= INCORRECT GEAR RATIO
P0742= TCC STUCK ON ??? DONT KNOW WHAT THIS MEANS
P1106= MAP SENSOR CIRCUIT INT HIGH
P0108= MAP SENSOR SIGNAL HIGH !

Today I have changed the Tps and MAF sensor still shifting hard :( ?
right now the cars battery is disconnected ( Im trying to reset the computer to clear these codes ) drove the car to the country roads and press the gas all the way down the car has NO power ! will not go pass 3100 RPM ? and seems to shift better when gas is press all the way down? the car also shifts around 3200 rpm ??
Any help would be great !!


Thanks
Joshua,

[ALERO81]

I FIXED THE BITCH !!! WOW
As a last ditch effort I went threw a change the BARO sensor and wow the car runs and drive better then ever lots of power now ! and best yet NO HARD SHIFTS ... thanks all for the help !!

[Midgear]

lol.. whats a baro sensor? O_o

[Redog]

^^^ x2 :wacko:

[Alerosaint]

x3 that would be the????

[ALERO81]

..lol ok that what I said ??
BARO=barometric pressure sensor computer code P0108

[Midgear]

WTF? our cars have a damn barometric pressure sensor? O_o

P0108= MAP SENSOR SIGNAL HIGH

[jayson_waltz]

P0108 generically has to do either with MAP or barometric sensor. our car has the MAP, so that must have been what u replaced.

[ALERO81]

P0108 generically has to do either with MAP or barometric sensor. our car has the MAP, so that must have been what u replaced.

To be honest with you I have no idea what it is a friend of mine went with me to the junk yard and he pick it up I was told that it was a Baro sensor I dont know don't know and dont car I'm just Happy the car works GREAT NOW

[jackal2000]

Manifold Absolute Pressure.

[Midgear]

aaaaand.. what's the purpose of this sensor? in the intake manifold?

[Redog]

From wikipedia.org


A manifold absolute pressure sensor (MAP) is one of the sensors (http://en.wikipedia.org/wiki/Sensor) used in an internal combustion engine (http://en.wikipedia.org/wiki/Internal_combustion_engine)'s electronic control system. Engines that use a MAP sensor are typically fuel injected (http://en.wikipedia.org/wiki/Fuel_injection). The manifold absolute pressure sensor provides instantaneous manifold pressure (http://en.wikipedia.org/wiki/Manifold_pressure) information to the engine's electronic control unit (http://en.wikipedia.org/wiki/Electronic_control_unit) (ECU). This is necessary to calculate air density and determine the engine's air mass flow rate, which in turn is used to calculate the appropriate fuel flow.

[jackal2000]

the way it is set up from the factory, the PCM uses the MAP sensor for baseline fuel calculations or volumetric efficiency (VE). the MAF sensor fine tunes those calculations to make the car run as it should. in the event of a MAF or MAP failure the PCM will switch to speed density mode and use the VE table in the PCM by itself for fuel calculations. usually cars running in speed density mode do not run very well and the shift pressures default to max, hence hard shifts some people complain about.

[Midgear]

would these hard shifts damage the transmission eventually?

[jackal2000]

i dont know if damage is right word. it will wear down the plates and gears much faster though.

[Midgear]

someone told me automatic transmissions run off of BELTS.

but you say plates and gears :lol: we need a picture of our transmission cut in half- or completely opened up or taken apart.. or something

[ALERO81]

the way it is set up from the factory, the PCM uses the MAP sensor for baseline fuel calculations or volumetric efficiency (VE). the MAF sensor fine tunes those calculations to make the car run as it should. in the event of a MAF or MAP failure the PCM will switch to speed density mode and use the VE table in the PCM by itself for fuel calculations. usually cars running in speed density mode do not run very well and the shift pressures default to max, hence hard shifts some people complain about.

Jackal2000 you know your stuff I just wish I new this 2 weeks ago :coolio:
but as I said before Im just glad this is now fixed !
Honestly it is like driving a brand new car with all kinds of power now !

[Midgear]

^^^ lol dont abuse your new found power :lol:

[ALERO81]

^^^ lol dont abuse your new found power :lol:

..... lol ok I will try not too!

[jackal2000]

someone told me automatic transmissions run off of BELTS.

but you say plates and gears :lol: we need a picture of our transmission cut in half- or completely opened up or taken apart.. or something

there are bands, not belts i believe. i have never seen the insides, just regurgitating what i have read/heard.

[Cliff8928]

the way it is set up from the factory, the PCM uses the MAP sensor for baseline fuel calculations or volumetric efficiency (VE). the MAF sensor fine tunes those calculations to make the car run as it should. in the event of a MAF or MAP failure the PCM will switch to speed density mode and use the VE table in the PCM by itself for fuel calculations. usually cars running in speed density mode do not run very well and the shift pressures default to max, hence hard shifts some people complain about.


The PCM can't use speed density if the MAP fails. The MAP is an integral part of speed density operation. All of the 4-cylinder Aleros only use speed density.

You can however tune the PCM to run well in speed density (MAF-less) mode with tuning software.