tps problem

compucarracing · #1 (**permalink**) 07-11-2010, 01:05 PM

I have a tmw 8 pack induction hooked up to my xfi and the tps always reads zero. I tried a new tps from tmw.. still zero sensor ground is good. If i jump the ref to signal wire I see reference voltage at the computer but wont work thru sensor. I hooked up jumper wires from the tps to the harness. If I disconnect the center, signal wire the sensor value changes normally but as soon as I hook up the signal wire the voltage drops to zero. I am wondering if the tmw sensor has different resistance values than the sensors that fast supplies? My cts ats are also stuck at 255 degrees. The fan runs all the time. I have checked the resistance of all the wires from the computer to the sensor connectors and the resistance was below .4 ohms in all cases with no shorts to power or ground. The system was tuned by a company in cincinnati ohio on an engine dyno but was always hard to start and I hooked it to my laptop and discovered the above mentioned problems. I think that the tuner I used new the problem was there just choose not to deal with it. I want to solve the problem to make this a more reliable setup. Can someone help! Oh ya..there is a code 31
Thanks,
Scott

TurboNova · #2 (**permalink**) 07-12-2010, 12:29 PM

Sounds like a harness problem all of the sensor signals use a common ground wire located at FAST C-11

If you are having problems with the air and water temp values are also not right then that is the only shared circuit.

The other question I have is all of the main grounds grounded directly to the battery?

Do you have 5volts on the voltage when you probe the 5v wire and use the ground wire on the connector for your volt meter? I would suspect the ground is the problem and you will only see 5v if you ground it some where else.

FAST Tech Maxwell · #3 (**permalink**) 07-12-2010, 03:45 PM

Just a couple of things to add.

1. If you are using C-Com XFI version 1.340, then make sure your ECU Firmware is 56. You can view it by going to View>Display ECU Configuration. Goofy things can show up if there is a firmware/software mismatch.

2. You can go to View>Display ECU Fault Status to see what is causing your error code. A code 31 is odd, so it looks like you have more than one thing causing the code.