TPS voltage problem (searched but no dice)

[jasonlee]

alright I am working on this car for a friend, I got a safc installed, and turned the key to the on position to start seting up the safc.... and it shows the tps at 100% with the arrow turned to the up position like RRE says its supposed to. so i checked the sensor wiring with a multimeter, and it shows 5.8V from the brown/red wire to the black wire (I am assuming this is ground)

the weird thing is it shows this voltage when it is not plugged into the sensor.. thats just the harness..... mabye something messed up in the ecu?

 

[steve]

I'd bet on the install.
Without knowing what car your doing this to, your wasting our time.

Steve

 

[jasonlee]

all right here are the details:

its a 1998 dodge avenger, converted to awd with a 1995 eclipse as the donor car. wiring, is all 1995, ECU is 1997,

(here are the install pics: http://redefinedrides.com/kyles.html

its got a 6 bolt 1g engine with a 2g head, 16g turbo, dnp manifold, greddy egt gauge, apexi turbo timer, safc, 650cc injectors, apexi down pipe and 3" cat back exhaust

everything else works great, the car starts and idles, although quite rough because it has no tune on it yet.. its only been started twice just to make sure it would.

the alternator may be bad because the brake light on the dash, and the battery light are lit up, and both shut off when the alternator is unplugged. the brake fluid is full, and the sensor on the brake fluid resivior is working properly... as well as the ebrake switch is working correclty too.

everything checks out 100% execpt I am getting voltage from the ecu on the brown with red wire for the TPS sensor....

 

[jasonlee]

just a little more info on this..

the brown/red wire at the ecu doesnt show any voltage unless the tps is plugged in, then it shows like 5.8 volts or something,

when I unplug the harness under the hood, and test the wires, the black wire (I am assuming supplies power instead of ground to the tps now) is about a 6 volt signal...

I did the tps tests, and it seems like the sensor is ok... is that black wire supposed to be suplying power, or a ground? is it supposed to be 6 volts, or 12? or less??

thanks

Jason

 

[jasonlee]

well, I checked the voltages on another car and found them way different.. the black was a ground... blah blah blah..

so i swapped out the ecu and bingo... no more problem. musta been the install jk

 

[steve]

Glad you solved it.

For reference the +5v sensor power on a 2G is the Green/Yellow wire.
The Brown/Red wire is the output of the TPS voltage divider.
As you know know the Sensor Ground is Black.

Sorry, I don't usually use the wire colors but the pins on the connectors, so I had to dig out my 2G wiring diagrams to follow along.

It's interesting that the other ECU was that messed up and still started the car.

Steve

 

[jasonlee]

I thought so too... i wonder if there is a way i can have it tested or something mabye fixed?

thanks for the wiring info... i wont likely forget it very soon haha