Issues with "TPS idle" - S13 ka24de ECU

[adamky]

I'm having trouble getting the TPS Idle flag to light up red in Consult (s13 ka24de ecu). The problem is that the voltage at which TPS idle activates seems to keep changing. For instance, earlier this week, I was having to adjust TPS down to .38V to get it to light up red. I put in a brand new sensor today, and now it seems to activate around .20V. But, here's the thing... it jumps around. If I rev the engine a few times, it starts activating at an even lower voltage, like .16 volts. Rev it a few more times, and now it's kicking in at .20 or .22 again. The old sensor was also jumping around like this, only it would switch from .34V to .40V, or somewhere around there.


This is driving me crazy. Because TPS idle isn't getting activated every time, my idle is extremely unstable, and the car is dying when coming to a stop because TPS idle never kicks in. I was under the impression that the ECU only uses TPS voltage to determine TPS idle conditions, but I am starting to wonder if there isn't something else that affects this that I don't realize. Or, maybe I just keep getting bad sensors and need to pick up an OEM one? Any suggestions would be great, because I don't understand what's going on.

[adamky]

I just ordered an OEM TPS sensor, because I just don't know what else to do here. I was hoping someone on here might have heard of this problem.

Would it help if I recorded a log file showing how this happens?

[Matt]

I havent heard of this before. Can you get a log file with rpm, tps, inj time, tp in stream mode so I can see it?

[louiswun]

Same issue happened on my customer's S14 AT or MT, also BNR32 GTR,
it might be happen when forgot to switch off the ecu power before unplug the TPS,
I'm not sure would this help on your case,
just try this to reset the TPS,
adjust the TPS voltage to 0.45v - 0.5v (temporarily neglect the TPS Idle switch)
unplug all TPS related plugs, you will see the TPS voltage raise to around 5v,
turn off the key while the TPS plugs are unpluged (power off the ecu),
turn on and off the key for 5 times while all the TPS plugs are still unpluged,
plug the TPS back when the ecu power is off,
turn the key on to check if the TPS idle switch is back to normal at 0.45v - 0.5v.
there might be an error code show in DTC, just clear it and your are done.

Hope this could help !

[adamky]

Same issue happened on my customer's S14 AT or MT, also BNR32 GTR,
it might be happen when forgot to switch off the ecu power before unplug the TPS,
I'm not sure would this help on your case,
just try this to reset the TPS,
adjust the TPS voltage to 0.45v - 0.5v (temporarily neglect the TPS Idle switch)
unplug all TPS related plugs, you will see the TPS voltage raise to around 5v,
turn off the key while the TPS plugs are unpluged (power off the ecu),
turn on and off the key for 5 times while all the TPS plugs are still unpluged,
plug the TPS back when the ecu power is off,
turn the key on to check if the TPS idle switch is back to normal at 0.45v - 0.5v.
there might be an error code show in DTC, just clear it and your are done.

Hope this could help !

Thanks for that. Someone actually recommended something similar on ka-t.org that worked great. Here's what he said to do:

Unplug the tps and turn the ignition on for a few minutes. When you reconnect it the ecu sets that voltage as the tps idle voltage.

Even after connecting the new OEM sensor, TPS idle wouldn't activate at 0.4V at first. So I used the above method and it reset it. Works perfect now. It looks like you're describing pretty much the same thing, except for the part about turning the key on and off 5 times. Don't think that part is necessary.

By the way, I've learned my lesson with aftermarket TPS sensors. Avoid them at all costs!! I went through two that had quite a bit of play in them. I could crack the throttle a tiny bit while idling, and the voltage wouldn't change at all. The RPM's would go up a little, but the voltage would just stay the same. This new OEM one works perfect.

[Matt]

Never heard of that one. Good info!

[adamky]

Never heard of that one. Good info!

Yeah, this must be why the voltage at which TPS idle activates kept changing on me. When diagnosing TPS issues and trying to get it working, I was unplugging it, turning off the key, turning on the key, plugging it back in, etc.,... so I was constantly resetting the TPS idle voltage without even realizing it. Combine that issue with a non-OEM sensor with a lot of play, and it's easy to see how frustrating this was!!

Now if I could just get 9.14.19 or 9.14.20 to work correctly! Consult keeps disconnecting after just a few seconds. I switched back to 9.14.13 by re-running the installation file and it's working again. SO it doesn't seem like it would be a driver issue or anything.

[Matt]

try 0.9.13.21

sorry about the problem in those previous releases. some of the new knock highlighting code screwed up the connection on the S13/S14 KA24DE models which I fixed as soon as I found it (having to do with those ECUs dont have knock maps so there was nothing to probe and consult went idle)

[Preston]

I didn't know the s13 ka didn't have knock maps...I leave those stock anyways but is there a way you can disable those or remove them for ease of use?

That comment also answered my next question... I heard about the new turn on CEL when knock maps being accessed...guess I don't have to worry about that feature

[Matt]

Well S14 KA24DE doesnt have knock maps anyway but it has VE tables (have to double check S13 perhaps it did have them)

Turn on CEL has not been implemented. That was an assumption - the highlighting is inside Nistune against the fuel/timing maps. Its still being tested with different ECUs at this time

[adamky]

Thanks, I'll try 9.14.21. I figured there might have been problems since 9.14.20 came out so quickly after 9.14.19.

S13 ECU's do have knock maps, btw.