jt_2002_ta

iTrader: (3)

first off this isnt the car in sig,but is a cammed,stalled camaro with 4l60. car drove fine for about 8 miles yesterday then started to slip badly. had a code for tps low voltage p 0122 and one for the maf p0102. the car is fine for a minute once its turned off and started up again. it wont move at all,shut it off start it up and moves fine for a few blocks. i replaced the tps sensor. didnt help. any ideas? i feel its a easy fix but idk. any help is appreciated

01ssreda4

iTrader: (96)

Tried unplugging the MAF? How about reading the volts the TPS is putting out.

jt_2002_ta

iTrader: (3)

haven't tried this yet. how do i read the volts, multimeter?

jt_2002_ta

iTrader: (3)

and i dont know if this matters but when the check engine light came on and was showing the codes the car drove fine. now the light is off and the car is having the slipping issue. and there is no codes for the transmission. if it was a internal issue with the trans woulnt there be codes for it? could a fluid and filter issue cause this?

jt_2002_ta

iTrader: (3)

11.0v at black wire and 5.0v at grey wire.

mantycarguy

Sounds like you've got battery voltage shorted to ground. Black wire is the ground side of the circuit. Check to make sure your pcm grounds are ok. Ive seen bad grounds causing all kinds of stray voltage backfeeding onto other circuits.

jt_2002_ta

iTrader: (3)

alternator is a bit weak if that matters. should read 11.5-12v on black wire correct? i would assume weak alt is why reading 11v. i dont think a weak alt would cause this?

01ssreda4

iTrader: (96)

Where do y'all people come from?

Op, the purple wire (if memory serves) is the output wire to the computer. It will show something like 0.50 for no throttle and sweep to around 4.65v for WOT. The maf is obviously causing your issues because when its faulted (ses light is on and the computer ignores it) there is no issue. When your computer reads the error'd maf, you are having problems. How are they related? Glad you asked. The computer adjusts trans fluid pressure based on engine load. It determines load using sensors, one of which is the maf. Faulty signal, haywire trans behavior, ignored faulty signal, trans resumes normal function. Thank you and good night!

jt_2002_ta

iTrader: (3)

makes sense. gonna try swapping the maf. thanks 01ssreda4. glad there are people that know their stuff to help people like me that are learning still.

jt_2002_ta

iTrader: (3)

i unplugged the maf and it still does it. i got a truck i can pull the maf off and try. do you think it would make a difference even though unplugging didnt?

01ssreda4

iTrader: (96)

Is it back to throwing the code? What was the code before?

jt_2002_ta

iTrader: (3)

no its not throwing any codes at the moment unplugged or not. they was p0122 for the tps which i replaced and the p0102

01ssreda4

iTrader: (96)

Leaving the Maf unplugged for long enough should fault it. Understand, though seemingly simple, sometimes these pcms can be finicky about failing the MAF and going into speed density mode. Speed density fault should cause max line pressure and restore your transmission feel. If it doesn't, you may have a transmission problem but I wouldn't point to that just yet .

mrvedit

As 01ssreda4 mentioned, the PCM adjusts the trans line pressure according to the engine load. It reads the TPS, MAF and MAP. When you disconnect the MAF it uses only the TPS and MAP. The TPS is probably the most critical; as mentioned it should read between 0.5 and 5 volts. If it goes below about .15V you will get get a code.

However, the trans will only change the line pressure in a range, typically 50psi to 185psi on a stock setup. 50psi is plenty to lightly accelerate the car. If your car does not move at all, I suspect your line pressure is extremely low due to a transmission problem. Under some conditions where the PCM gets bad readings from the MAF, TPS or MAP (or detect trans slippage) it goes into "safe" mode where it maxes the line pressure to protect the trans and get you home.

jt_2002_ta

iTrader: (3)

so when it did get bad readings and the ses light was on it maxed out line pressure and that is why it seemed ok? i mean its fine for a minute then no movement. turn off, immediately start up and fine for a bit. just seems like if it was transmission damage it would not move at all

jt_2002_ta

iTrader: (3)

let it run for 15 minutes or so unplugged and no ses light. is there a issue with that? could it be a pcm issue maybe?

01ssreda4

iTrader: (96)

Did you try unplugging the tps?

jt_2002_ta

iTrader: (3)

no. i replaced it but it could be bad also i suppose. i will try that, or am i just trying to get the pcm to throw a code

01ssreda4

iTrader: (96)

No by unplugging it I'm wondering if it throw you back to a higher line pressure so you can see how long the trans will function, or how much it can function. You can probe the purple wire and that will tell you if the sensor is responding correctly.

jt_2002_ta

iTrader: (3)

unplugged it and still the same. didnt get a ses light either