Electrical gremlins in my car ONLY at track days?!
#1
Registered User
Thread Starter
Electrical gremlins in my car ONLY at track days?!
Help, my car has a Gremlin and it is driving me mad!
Apologies for the big post, but I'd really appreciate any ideas.
I'm not sure what is going on but only at track days I am getting the following problems:
Until today only the speedo has played up before and has caused the engine and other light mentioned above.
I have a Hondata Flashpro fitted to the car and also a yellow box from having a 4.44 rear gearset fitted.
I got the flashpro and yellow box at the same time and the problem has only been since they were fitted.
With just the speedo problem I was thinking it was a yellow box problem. However with the fuel gauge and power cut starting today I am thinking it could be flashpro related.
I tried clearing the code (P0720) at the track via the Torque app but it wouldn't go. At lunch after about a five minute rest it wouldn't clear. The speedo mucked up the whole way home including after stopping the car and switching off for petrol. I also switched off after each run throughout the day and that didn't help.
Here is the interesting bit. I get home, leave the car turned off for 20mins whilst washing the wheels. Turn it back on and I can clear the code and CEL light! Speedo now works fine again. It as always F'ing does this when I get home!
Given this only happens at the track and does seem to sort itself out when home I have come up with some crack pot theories:
I've all this on video so I'll have to work on an edit to post up here.
Thanks a lot if you made it this far
PS I only drive the car a handful of times a month so perhaps not long enough/hard enough on road for it to rear its head but perhaps all these problems are always there, it just takes a days solid days driving to clock enough time up on the car for them to show themselves?
Apologies for the big post, but I'd really appreciate any ideas.
I'm not sure what is going on but only at track days I am getting the following problems:
- Speedo gets a mind of its own. It will read numbers at random and today it even stuck on 0 for a large part of the day, even when doing 130mph+
- Petrol gauge has a mind of its own. I had a quarter of a tank and in one instant it went to empty! I went and filled up and only 45l went in. On the drive home I watched it go from one quarter of a tank to just over half full one notch at a time moving up one notch per second and then stopping and then going back down in the same way. It also kept moving erratically the whole drive home.
- Check Engine Light is coming on sometimes and wont clear. Pulled the code, P0720, 'Output Speed sensor unit' is the fault. I'm not convinced the sensor is at fault and causing the speedo errors, as you'll see later on.
- Steering wheel light and '!' next to it is coming on some times.
- Car won't rev past 6 or 7k approx occasionally. Normally 4 laps or so in the car won't rev past 6 or 7k, tends to be on the main straight and not just after the corner. It doesn't bounce off a limiter, it just won't rev past it. I leave it a few corners and all is back. No engine fault codes present on ECU.
Until today only the speedo has played up before and has caused the engine and other light mentioned above.
I have a Hondata Flashpro fitted to the car and also a yellow box from having a 4.44 rear gearset fitted.
I got the flashpro and yellow box at the same time and the problem has only been since they were fitted.
With just the speedo problem I was thinking it was a yellow box problem. However with the fuel gauge and power cut starting today I am thinking it could be flashpro related.
I tried clearing the code (P0720) at the track via the Torque app but it wouldn't go. At lunch after about a five minute rest it wouldn't clear. The speedo mucked up the whole way home including after stopping the car and switching off for petrol. I also switched off after each run throughout the day and that didn't help.
Here is the interesting bit. I get home, leave the car turned off for 20mins whilst washing the wheels. Turn it back on and I can clear the code and CEL light! Speedo now works fine again. It as always F'ing does this when I get home!
Given this only happens at the track and does seem to sort itself out when home I have come up with some crack pot theories:
- The extreme cornering only seen on the track is causing a loose connection or earth, perhaps as a result of the flashpro install or yellow box.
- Heat, the car and perhaps ECU (?) are working at much higher temps causing some sort of issue.
- Speed, the car is never driven above 100 normally, perhaps there is something up with the flashpro or yellow box that doesn't like the higher speeds.
- Power cut could be down to the mapping?
I've all this on video so I'll have to work on an edit to post up here.
Thanks a lot if you made it this far
PS I only drive the car a handful of times a month so perhaps not long enough/hard enough on road for it to rear its head but perhaps all these problems are always there, it just takes a days solid days driving to clock enough time up on the car for them to show themselves?
#3
Registered User
Thread Starter
mmm, people getting this code with HOndata Kpro before
https://www.s2ki.com/s2000/topic/821...o-on-a-my2006/
Also looks like there is more than one way the yellow box could be wired up.
https://www.s2ki.com/s2000/topic/815...elerates-slow/
https://www.s2ki.com/s2000/index.php...&f=22&t=119078
It has to be down to all this I reckon
https://www.s2ki.com/s2000/topic/821...o-on-a-my2006/
Also looks like there is more than one way the yellow box could be wired up.
https://www.s2ki.com/s2000/topic/815...elerates-slow/
https://www.s2ki.com/s2000/index.php...&f=22&t=119078
It has to be down to all this I reckon
#7
From reading the other threads, it seemed the errors were more common when the yellowbox was wired up close to the ECU rather than taking the feed wire off the speed sensor on the transmission housing.
If i was guessing, i'd say that if you wired it close to the ECU you were somehow changing the resistance in the circuit by shortening the length of the cable and the ECU picks this up as a fault hence the limp mode situation either that or something in the yellowbox itself sends an incorrect signal when it's cable run to the ECU is decreased.
If i was guessing, i'd say that if you wired it close to the ECU you were somehow changing the resistance in the circuit by shortening the length of the cable and the ECU picks this up as a fault hence the limp mode situation either that or something in the yellowbox itself sends an incorrect signal when it's cable run to the ECU is decreased.
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#8
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#9
Registered User
Thread Starter
From reading the other threads, it seemed the errors were more common when the yellowbox was wired up close to the ECU rather than taking the feed wire off the speed sensor on the transmission housing.
If i was guessing, i'd say that if you wired it close to the ECU you were somehow changing the resistance in the circuit by shortening the length of the cable and the ECU picks this up as a fault hence the limp mode situation either that or something in the yellowbox itself sends an incorrect signal when it's cable run to the ECU is decreased.
If i was guessing, i'd say that if you wired it close to the ECU you were somehow changing the resistance in the circuit by shortening the length of the cable and the ECU picks this up as a fault hence the limp mode situation either that or something in the yellowbox itself sends an incorrect signal when it's cable run to the ECU is decreased.
#10
Registered User
Thread Starter
It was the best track day ever, once I knew the CEL wasn't anything serious and the rev issue didn't happen too much. All I can say is Stoptech rule