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Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 4970
Experience:  ASE master tech for 40 years
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On a 1997 Chevy s10 throttle positioning code, changed the

Customer Question

On a 1997 Chevy s10 throttle positioning code, changed the sensor, checked the gray wire, not getting 5 volts, replaced the Pcm with one on eBay the volts on grey wire just jumping around
Submitted: 11 months ago.
Category: Chevy
Expert:  Roy replied 11 months ago.

good afternoon my name is ***** ***** I will assist

the pcm you purchased, did you have it flashed to your truck?? it needs to have an operating system just like a computer or it wont work

Roy

Customer: replied 11 months ago.
The seller said he flashed it everything works good except the problem with the tips sensor original one had same problem. I'm connectin the original one back right now
Expert:  Roy replied 11 months ago.

does the check engine light come on with key on engine off???

are any other wires at the tps have 5 volt reference????

Roy

Customer: replied 11 months ago.
Engine light is on, even if I try to clear it, it doesn't turn off, black wire 12 volts grey wire jumps around blue wire jumps around
Expert:  Roy replied 11 months ago.

check engine light should be on with key on engine off.

if it is running, then I need the code. do not clear anything until the failure is found. clearing does nothing.

jumps around?? what voltage?? looking up wiring diagram

Roy

Expert:  Roy replied 11 months ago.

ok, the black wire should read 0 volts as it is a ground

the other 2 should read 5 volts solid. this is with the connector removed from the sensor.

re check for me please

Roy

Customer: replied 11 months ago.
P0122 p1122 p0462
Expert:  Roy replied 11 months ago.

and the voltages????

Roy

Customer: replied 11 months ago.
Okay blue wire with red lead to connector and black lead to batter ground jumps 43.0 mv
Customer: replied 11 months ago.
Grey wire hooked the same is 195. 3 mv
Customer: replied 11 months ago.
Black 12 volts with with black lead on connector and red on Batter power source
Customer: replied 11 months ago.
Tester continuity from connector to pcm, checks out good
Customer: replied 11 months ago.
The connectors to the pcm
Expert:  Roy replied 11 months ago.

why are you connecting to anything??? I just want the voltage with the connector off and nothing else. you jumping wires may be damaging the pcm you just installed

Roy

Customer: replied 11 months ago.
Not jumping anything just tested continuity to see if wire is broken,
Expert:  Roy replied 11 months ago.

Black 12 volts with with black lead on connector and red on Batter power source

your words. there is never 12 volts to this sensor if you applied 12 volts to the black wire, you damaged the pcm

Roy

Customer: replied 11 months ago.
I have other vehicles here, I tested out the same way and everything checks out good, and the vehicles run just fine, I didn't add 12 volts to anything I checked that the ground was working with a multimeter, same as I always do, just wanting to know why the connector isn't getting 5 volts from the pcm,
Expert:  Roy replied 11 months ago.

because the pcm is no good and needs to be replaced.

Roy

Customer: replied 11 months ago.
if it isn't getting 5 volts it had to be the pcm, it can't be anything else and what are the odds of the 2 pcm having the same problem with only the tps, if it wasn't flashed right, wouldn't a lot of other things be going wrong
Expert:  Roy replied 11 months ago.

buying used from e bay is always a risk. it is a used part not new. yes, it can be bad.

you need a correct flash from a shop with the proper scan tool in order for it to work.

that assuming your pcm was the original failure

Roy

Expert:  Roy replied 11 months ago.

how are you making out

Customer: replied 11 months ago.
no 5 volts I guess the computer again, I'm not sure, if I buy a new computer and flash it through the dealer it should read 5 volts and work properly u think
Expert:  Roy replied 11 months ago.

definitely. and that is the correct way to get the part. I have never had success with buying anything off e bay electronic for a car.

Roy

Customer: replied 11 months ago.
Okay thank u
Expert:  Roy replied 11 months ago.

your welcome

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Expert:  Roy replied 11 months ago.

please dont forget to rate me as it is the only way I get paid for my efforts

Roy