Need help with TPS

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Frisco

Newbie
Joined
Jan 6, 2022
Messages
12
Reaction score
5
Location
Texas
So I have a 1995 c1500 pulling a low TPS voltage code (22) I have replaced the TPS gone through the service manual and it said either faulty TPS or bad connection i cant really see anything that looks like there would be a faulty connection but I'm pretty new to a lot of this stuff and Ive hit a roadblock so ill take any advice
 

AuroraGirl

I'm Awesome
Joined
Jul 27, 2020
Messages
1,033
Reaction score
1,178
Location
Northern Wisconsin
So I have a 1995 c1500 pulling a low TPS voltage code (22) I have replaced the TPS gone through the service manual and it said either faulty TPS or bad connection i cant really see anything that looks like there would be a faulty connection but I'm pretty new to a lot of this stuff and Ive hit a roadblock so ill take any advice
your TPS has a 5 volt reference, a ground wire to the ECM, and also return wire that changes voltage according to position. ddi you properly install the TPS and can you probe the wire coming off the sensor as Return for voltage from low up to 4.50 ish and be consistent increase directly tied to operating the throttle with your hand

if that works, your wiring is bad some where on that line after your hand touching it and the ECM or the ECM has an internal issue.
 

AuroraGirl

I'm Awesome
Joined
Jul 27, 2020
Messages
1,033
Reaction score
1,178
Location
Northern Wisconsin
if your 5volt reference isnt there Or it changes or isnt 5 volts, you have other problems. They can get complex but it should always bee 5 volts at key on and when doing the throttle changes.
the ground being an issue would also affect things but that can get involved too.Your ECM ground is the first thing id check assuming the ground is not interupted all the way to the ECM.
to my knowledge, there is a ground on your thermostat housing. is that there?
 

Frisco

Newbie
Joined
Jan 6, 2022
Messages
12
Reaction score
5
Location
Texas
if your 5volt reference isnt there Or it changes or isnt 5 volts, you have other problems. They can get complex but it should always bee 5 volts at key on and when doing the throttle changes.
the ground being an issue would also affect things but that can get involved too.Your ECM ground is the first thing id check assuming the ground is not interupted all the way to the ECM.
to my knowledge, there is a ground on your thermostat housing. is that there?
yeah getting 5 volts, ive jumped the 5 volt back to signal and pulled a code 21 for TPS high voltage, ecm ground is good. Ive back probed from the tps and it was jumping around form .2 to .1 volts with throttle closed. service manual says code will come on at .2 and less and normal should be about .5. i have no clue about the thermostat ground i will be out there to check tomorrow. only problem i can see is signal at the tps im not sure if i installed it right or not i just assumed you throw it on there and bolt it down so issue could lie there as well.
 

1997

I'm Awesome
Joined
Aug 2, 2013
Messages
1,139
Reaction score
2,121
Location
B.C. CDN
Are you testing at the ECU connectors?

Blue connector:

F-14GRY5 Volt Sensor Reference Voltage (TPS, MAP)

Red connector:

A-15DK BLUTP Signal

you can check connectivity etc from those connectors also, (need to disconnect battery etc when doing that)
 

PlayingWithTBI

2022 Truck of the Year
Supporting Member
Joined
Jan 3, 2019
Messages
9,546
Reaction score
14,666
Location
Tonopah, AZ
Ive back probed from the tps and it was jumping around form .2 to .1 volts with throttle closed. service manual says code will come on at .2 and less and normal should be about .5.
Yes ~.5 is what you want. Some TPS come with slotted mounting holes, otherwise you can drill or use a moto tool to slot them and adjust until you get closer to .45V+ then, at WOT you should see ~4.5V

Note: Here's mine when I bought the 46mm bored TB from SPR Performance. He supplies flow matched injectors, new AIC and calibrated TPS.
You must be registered for see images attach
 
Last edited:

Frisco

Newbie
Joined
Jan 6, 2022
Messages
12
Reaction score
5
Location
Texas
Are you testing at the ECU connectors?

Blue connector:

F-14GRY5 Volt Sensor Reference Voltage (TPS, MAP)

Red connector:

A-15DK BLUTP Signal

you can check connectivity etc from those connectors also, (need to disconnect battery etc when doing that)
yeah i have tested at ECU now that i think about it though those grounds at the thermostat housing (three i think) were cut for some reason.
 
Last edited:

AuroraGirl

I'm Awesome
Joined
Jul 27, 2020
Messages
1,033
Reaction score
1,178
Location
Northern Wisconsin
yeah if youre missing grounds its probably a good idea to remake them and find a good place for them either there or elsewhere but with no high voltage or amperage grounds of other circuits running over or past them.
 

Frisco

Newbie
Joined
Jan 6, 2022
Messages
12
Reaction score
5
Location
Texas
yeah if youre missing grounds its probably a good idea to remake them and find a good place for them either there or elsewhere but with no high voltage or amperage grounds of other circuits running over or past them.
no change gonna find somewhere else to ground them thermostat bolt was very rusty. question though would the grounds affect the signal coming out of the TPS when cause Im testing at the tps and getting a low signal voltage.
 
Top