CalebjW02 Posted June 3, 2023 Report Share Posted June 3, 2023 So I’ve already gotten a new TPS and installed and calibrated it. Using my ohmmeter I verified it’s in the correct position, but one thing I notice is how when I slowly open the throttle and watch the ohms rise. It all the sudden cuts out to infinity and then goes back to normal. So every time I go to calibrate the TPS in link software it just reads wrongs. I’m not sure what’s causing this, maybe grounds. The Link just sees it at 100% except when idling. Then it’s okay, is this how the sensor is supposed to work? Any help appreciated, trying to start tuning. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 3, 2023 Report Share Posted June 3, 2023 What does the TPS voltage show on the AN Volt runtime? Does it vary steadily with throttle movement by say more than about say 3V from closed to open? Quote Link to comment Share on other sites More sharing options...
CalebjW02 Posted June 3, 2023 Author Report Share Posted June 3, 2023 So the tps voltage at idle it shows under 1 volt, but as soon as I crack the throttle the slightest bit it jumps to 4.99v and the tps % main jumps right to 100%… even though I really only have the throttle barely open. I did the oem tps calibration and it’s all in spec. Other than where it cuts to infinity ohms for half a second when opening. Any ideas.? I can’t really do any tuning with it always showing 100% Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted June 3, 2023 Report Share Posted June 3, 2023 Is it a 3pin TPS or 4pin? If it's 4pin you may have wired it to the "idle switch" connection which is there to tell older factory ECU's when you are fully off the throttle. They don't provide a linear output, its either on or off. Is the TPS a factory Toyota one or a aftermarket one for a aftermarket TB? What you're looking for is a smooth ramping output when moving the throttle and probing the appropriate pin. Different TPS sensors can operate in slightly different ways, but for example if its a 5k ohm range TPS with the pins; Pin 1 = Sensor GND Pin 2 = Sensor OUT Pin 3 = Sensor 5v Probing between 1 and 3 will give you 5k ohm, and wont change when the TB is moved Probing between 1 and 2 will give you 0 ohm, and will ramp up linearly to 5k ohm as you open the TB Probing between 2 and 3 will give you 5k ohm, and will ramp down linearly to 0 ohm as you open the TB Quote Link to comment Share on other sites More sharing options...
CalebjW02 Posted June 3, 2023 Author Report Share Posted June 3, 2023 It is a 4 pin, I didn’t re wire it but I did mess with the signal grounds and 5v outputs and I have them all tied together going into the correct spots in the ecu. I think it works off 5 ohm though because when I have ohm meter connected between VTA and E2 then it goes up to around 4.8 ohms. I thinks what’s causing the issue is where it cuts out to infinity for the half second when pressing down on throttle. Thanks for the replies so far! Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 3, 2023 Report Share Posted June 3, 2023 VC is 5V. E2 is sensor Gnd. VTA is signal. IDL is not used. Quote Link to comment Share on other sites More sharing options...
koracing Posted June 3, 2023 Report Share Posted June 3, 2023 It kind of sounds like you have IDL running to the VTA pin for some reason. I would continuity test the wiring given the above information @adamw provided. Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted June 4, 2023 Report Share Posted June 4, 2023 1 hour ago, CalebjW02 said: I think it works off 5 ohm This doesnt sound right for a Toyota TPS. They're typically around 2k or 12k range. 5 ohm is almost margin of error for cheap/bad multimeter leads and all you're measuring is the IDL/Idle Switch opening and closing. 35 minutes ago, koracing said: sounds like you have IDL running to the VTA pin for some reason. Or maybe E2 to IDL? So the Idle Switch is providing the ground while the TB is closed and as soon as the TB is opened beyond the Idle Switch trigger point the ground is lost and VTA just reads full 5v? Either way it should be pretty obvious to look at the TPS plug and figure out which 3 of the 4 pins have wires in them. Quote Link to comment Share on other sites More sharing options...
CalebjW02 Posted June 4, 2023 Author Report Share Posted June 4, 2023 So my TPS has all four of those wires currently wired up in the tps plug, so IDL isn’t used?? I know I have the signal ground hooked up right but it’s soldered to all the other signal wires then going into ecu. I’m going to maybe switch it over to the expansion loom signal ground Quote Link to comment Share on other sites More sharing options...
DerekAE86 Posted June 4, 2023 Report Share Posted June 4, 2023 Nope, not required for non-factory ECU setups. With the TPS unplugged just get your multi-meter and check for continuity between E2 and another known Sensor Ground, then VC and another known Sensor 5v. Then check VTA all the way back to the ECU plug. Can then check if IDL has continuity/resistance to any of the other TPS plug pins to figure out where things have gone wrong. Quote Link to comment Share on other sites More sharing options...
CalebjW02 Posted June 4, 2023 Author Report Share Posted June 4, 2023 So It looks like I have the IDL (pink wire in my case) wires up to tps signal…. I guess that’s prolly not right. It’s getting dark out now, I’m going to switch those around in the morning and see what is does. Thank you Quote Link to comment Share on other sites More sharing options...
koracing Posted June 5, 2023 Report Share Posted June 5, 2023 Signal wire is VTA - so yeah switch those and it should be ok. Quote Link to comment Share on other sites More sharing options...
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