I have a 96 Integra GSR. While accelerating, the car hesitated and Check engine light came on. Ran obd2, says low voltage on throttle position sensor. Got a used tps from a yard. checked it with multimeter. besides a fluctuation of 0.10 volts checked out fine. 0.40 at idle and 4.40 wide open with car not running. Tested wires goint to the tps. 5v going in and ground tested 001. Put the car together and still the same fluctuating throttle, high rpm at startup. Engine light came back on says the same low V on tps. Messed with all the wire connections and reset the comp. again. Car ran fine for 2 days and now once again the same exact symptoms. Rechecked tps and wires involved, now the ground wire is reading 098 continuity. Supplyed a ground from fire wall straight to the tps to see if that would work.... Now its acting even wierder. 2k rmp at startup, It will drop down to 1500 after N.O.Temp has been reached, but if it is reved it up, on the way back down it will stop at 2k for a minute and drop the rest of the way down at its leisure. If left at idle rpm will keep rising up and down on its own. Possibly Bad ECU? Any Ideas???

 

It's throwing the code because, well, your voltage is low. Recalibrate the TPS (Info on google) for .45v closed and 4.5v open. You won't have to move it much.

Your idle is likely either because of the code you're throwing or because of the IACV.

 

ok. so the update is, I disconnected the ground that I hooked straight up to the car and it lets the check light come back on and actually does better with the old weak ground. I guess the ecu needs that ground on their. I disconnected, cleaned and resurfaced the battery ground to the car and the ground from the engine to the body. The ground to the t.p.s. is now reading good 001. Adjusted the tps but I'm not sure if the specs are wrong or just variences in sensors, but in order to have the V at 4.5 open throttle the idle V has to be at .50 not 4.5.. I tried setting the idle at .45 but at full it only goes up to 4.45. But so far no check light seems fine. But what should I set the t.p.s to .45 to 4.45 or .50 to 4.50??

 

Either should be fine. They're both within spec for the vehicle to run properly.

 

agreed that either should be fine, but I find that the idle is more critical. I'd go with the .45 option.

 

Ok. So once again. back to the same issue.... Got the code again P0122
Checked the t.p.s 5v in, ground it good, .5v closed 4.5wot steady no jumping around. sweeps fine but the code came on low voltage input and the car idles at 1500rpm. Any ideas????

 

I have the exact same problem....only my tps code is for high voltage.if you figure it out let me know

 

Check the ground at the thermostat housing.

 

I'm also having a nightmare session with my tps should my ground volts be reading .003

 

I am was having similar issues; my input voltage was 4.7 and would run great and then throw a code. I have new installed a new TPS thinking it was going bad and now my ECU is putting out 3.7V (ECU pin to chassis and TPS connector to Battery -)

Any idea on why my ECU is now outputting 3.7V and not 5V

Engine is a JDM B18C ODBI with bolt on mods (intake, header, exhaust. etc.)

 

That's not the exact same problem, it's the opposite problem caused by a different issue. High voltage is most likely a ground problem.

Low voltage is typically a short. Something else is drawing your power back to ground. You need to check continuity from your power and signal wires to ground to figure out which one is shorting.

It could be a sensor drawing the power away, so you should disconnect all sensors, valves and solenoids before testing for a short. This isn't exactly a job a noob can perform, so if you aren't familiar with this or have a lot of time to figure it out, consult a shop.

It could however, be as easy as a loose/corroded pin in the plug at the ECU or sensor. It's not exactly easy to re-tension the pins if that's needed, but there are threads on here about it.

 

so I have tracked it down to the ECU pin/connector - I am not sure how to test the actual pin; have a link/thread handy that shows how to power the ECU and test pins on the D connector?

 

the 'pin' is just a hole with a metal band in it for tension. If it has significant resistance between the crimped end at the wire and the solder point in the ecu, snip off the old pin, crimp a new one on.
http://www.xenocron.com/obd1-pins-p-...45jr9cot2ib454