Our 96 Blazer SES light recently came on and I went to AutoZone and received these codes (P0102, P0108, P0122).
P0102 Mass or Volume Air Flow Circuit Low Input
P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0122 Throttle/Petal Position Sensor/Switch A Circuit Low Input

The thing runs great except for the fact that it shifts very harshly betweem 1 to 2. I wonder if that is a result of the TPPS. The transmission is a rebuilt one and has about 2000 miles on it. Anyone have a similar shifting issue?

 

Well to start with the MAF sensor needs to be checked visually to see if there is dirt/oil buildup on the sensor. If you are using a K&N or oiled foam filter then your MAF could be oil fouled. That could affect the other readings...it coud also affect the transmission since the computer takes readings from all these sensors to determine tranny functioning....

But for the hard shifting I would take it back to the shop that you got the rebuild tranny from and see if they can isolate the hard shifting issue. It could be also as simple as the kickdown (TV) cable is not adjusted properly...

 

I would just take the MAF sensor apart and clean it. If you've already got it out to inspect, might as well shoot some sensor safe tb cleaner on it.

Your TPS sensor can be checked with a multimeter for smooth and even increase/decrease in resistance through the complete rotation of the throttle blade.

Seeing as how all of these sensors have wires in the same harness, you may want to inspect the wiring harness for damage. It is very rare to just have all 3 of those sensors go bad all at once.

 

Thanks for the responses!

My brother already mentioned the TV cable adjustment and we'll do that this evening and we'll also be cleaning the MAF anyway.

Speaking of the TV cable, at what MPH should the shift between 1 and 2 take place?

Given that all three sensors threw codes, I've been inspecting all the wiring and connectiuons and have not found any problems yet but I'm not finished.

 

Um... Does a '97 even have a kickdown cable? I thought all of this was controlled by the PCM...

 

Good point! I'm not even sure yet. But I guess I'll find out when we clena the MAF.

 

Well...The MAF is clean now and tiny wires are intact. I have yet to find any wiring/connection problems from all 3 sensors. And, it does appear there is a TV cable. There are 2 cables going to the throttle linkage and I do not have cruise so I am assuming it to be the TV cable. I plan to adjust the TV cable this evening (ever so slightly) to see if there is any improvement in shifting between 1 and 2. I think I may also clear the codes and see what happens.

 

Don't know if you got to the TV Cable yet or have this information but I found this site at another S series site...

http://www.tvmadeez.com/article/index.php

It has instructions and pics for how to adjust....