fixed at last ! P0121, P2135, reduced engine power

[red fuji]

I finally figured out the root cause for all the troubles my 2007 Pontiac Torrent has been going through for the past 6 month...engine hesitations, erratic acceleration, P0121, P2135 Code, Reduced engine power (limp mode), service stability system warning, Stabilization disabled, and finally my entire display went out while driving.
i came to conclusion that the problem has to do with dirty TPS. i removed the sensor from the throttle body to see what needs to be cleaned and low and behold the solder points shorted out . i could see a tiny 'wire' going from one solder point to another- TIN WHISKERS !! removed the whisker and car is purring like a kitten again. one note, you have to break some plastic tabs to get to the actual electronics of the sensor; i had to glue things back up-but it works. !!


I suspect a good number of people have the Tin Whisker issue but don't know it.

BTW- same Tin Whisker encounter as the Camry that caused a few death.
http://nepp.nasa.gov/whisker/reference/tech_papers/2011-nasa-gsfc-whisker-failure-app-sensor.pdf

 

[melsg5]

thanks for the update

 

[red fuji]

According to this vendor Airtexve.com (automotive electronic parts), the sensor (w/o the throttle body) is used on these models...which would make them susceptible to Tin Whiskers shorts as well.

BUICK LUCERNE 11-06
BUICK TERRAZA 07-06
CADILLAC DTS 11-06
CADILLAC SRX 09-07
CADILLAC STS 10-07
CADILLAC XLR 09-07
CHEVROLET EQUINOX 09-07
CHEVROLET IMPALA 11-06
CHEVROLET MALIBU 10-06
CHEVROLET MONTE CARL O 07-06
CHEVROLET UPLANDER 09-06
PONTIAC G6 10-06
PONTIAC MONTANA 09-06
PONTIAC TORRENT 09-07
SATURN AURA 08-07
SATURN VUE 10-08

 

[melsg5]

I read the attachment, it's almost like the tin is alive!

______________________________

 

[patpeter]

Hi, thanks for the post. I have the same issue with my Pontiac Montana 07. Planning on following ur idea of cleaning the TPS. If you have any resources like how to video,I kindly request u to share. Thanks and have a good one.

 

[Zimgxp]

Youtube is your friend.

 

[red fuji]

here is a picture i found online of the sensor.
1. snap off the six metal clips; the sensor will separate from the valve body and car.
2. once you have the sensor on a work bench you will need to remove the copper plate shown in the picture. break off the plastic tabs (red arrows) that are holding it down then pry off the plate. ( i dont think you will be able to remove the plate w/o breaking those plastic tabs. i tried but didnt want to risk bending the plate.
after plate removal; inspect the soldering points for shorts. in mine i saw what looked like an out of place'wire' crossing from one solder point to another. i removed/flicked off that wire which solved the issue.

now the tricky part is securing the metal plate back on since the tabs holding it are no longer there. i used super glue (i suggest u use epoxy) to glue back on the plastic tabs that u broke off. now the other trick is keeping the plate from popping up while glue sets since the spring loaded 'brush' wants to press up against the copper plate- i used a spring loaded plastic clamp to hold the plate down. for (you will have to find the right clamp for the job)

i know the process sounds crazy but it works at the end if you have good common sense and know what you are doing. BTW...the metal plate is not really an 'electrical conduit'... its purpose is to hold down the 'contact brush against the potentiometer surface. Best of luck.