Error code 76

[beemn]

I have a mini r53 and this fault Error 76 has happened 3 times, twice during a race.  Can I just swap out the throttle body or is it a bit more involved than that??

[Adamw]

In the throttle body there are two independent throttle position sensors (we call them TP main and TP sub), there is two so they can be compared to each other, if they ever read differently then ecu knows there is a problem.  

Fault code 76 means the readings from the two sensors arent matching each other (there is about 2% error allowed). So this could be just a calibration issue, it could be a failing sensor (need to replace the whole throttle body), or it could be a loose connection/wiring issue. 

Have you got any logs?  If not can you give us one with just a few free revs in the garage.  And a copy of your tune.   

[beemn]

On 8/13/2022 at 9:53 PM, Adamw said:

In the throttle body there are two independent throttle position sensors (we call them TP main and TP sub), there is two so they can be compared to each other, if they ever read differently then ecu knows there is a problem.  

Fault code 76 means the readings from the two sensors arent matching each other (there is about 2% error allowed). So this could be just a calibration issue, it could be a failing sensor (need to replace the whole throttle body), or it could be a loose connection/wiring issue. 

Have you got any logs?  If not can you give us one with just a few free revs in the garage.  And a copy of your tune.   

Whoops thought I had sent this yesterday....Thanks Adam, I have just down loaded the tune, also not sure if logging had ever been set up so I have just given that a go too...hope I have done it right. The car is a bit too loud to rev up on a sunday but I can try again today if i havent done it right

test logging.llg Minichallenge.pclr

[Adamw]

Yeah no obvious problems in that log, they both match quite well.  That would suggest it is only an intermitant issue which makes it more difficult.  

You could either set up ecu logging to record all throttle related stuff so we have some data when it next occurs, or you can chance it and replace parts. 

 

[beemn]

Thanks,  so if i go logging> set up logging > and add everything under electronic throttle, this should be all?...not entirely sure which stuff i should be logging in general anyway 

[Adamw]

Thats odd, you should have another "ECU logging" tab on that screen.  Below is probably the setup we want.  

You should reach that setup screen from >logging>setup logging.  Is that what you are doing?  

[Vaughan]

10 hours ago, Adamw said:

Thats odd, you should have another "ECU logging" tab on that screen.  Below is probably the setup we want. 

Looks like he's opened PCLink and hasn't connected to an ECU or loaded a basemap, ECU logging tab will show as soon as a basemap is loaded or an ECU is connected to.

[beemn]

Sorry for the delay, yes I didn’t have it connected to the car in that photo, only just got around to it now 

[beemn]

while i have been trying to work out how to set the engine fan to stay on after shut off, the car done the fault while idling, im hoping the logging worked this time roundECU Log 2022-08-23 1;45;14 pm.llg 

[Vaughan]

That log only has TP Main, doesn't have TP Sub TP Error Accumulator, An 5, An 6 or most of the other runtimes from Adam's example setup.

[beemn]

47 minutes ago, Vaughan said:

That log only has TP Main, doesn't have TP Sub TP Error Accumulator, An 5, An 6 or most of the other runtimes from Adam's example setup.

I will give it another go tomorrow, I had moved across everything it would allow me to under E throttle if you see my photo above...will see where to find what's missing

 

To clarify when the car is running the ecu will automatically log? and when it does it auto saves with a time stamp...?

 

Sorry to be a pain!

[Vaughan]

3 hours ago, beemn said:

This photo doesn't show some of the things Adam said to log but it does appear to have a scroll bar so those might be just offscreen.

 

3 minutes ago, beemn said:

To clarify when the car is running the ecu will automatically log? and when it does it auto saves with a time stamp...?

The way you have it setup it will always be logging, it doesn't save with real time stamps, you just get multiple log files each of which have their own internal times but no indication of time between the logs or when the logs were taken as the ECU doesn't have a real time clock.

[beemn]

Just now, Vaughan said:

This photos doesn't show some of the things Adam said to log but it does appear to have a scroll bar so those might be just offscreen.

 

everything above the scroll was just default stuff maybe?...but from the log that I attached can you tell if what I have under logged parameter's in that pic are they actually in the log it self that you looked at?...if that makes sense

 

[Vaughan]

1 minute ago, beemn said:

everything above the scroll was just default stuff maybe?...but from the log that I attached can you tell if what I have under logged parameter's in that pic are they actually in the log it self that you looked at?...if that makes sense

Your log had all the runtimes from your picture in it but we need more information than that to see what is happening, add all the runtimes from Adam's picture as well please.

On 8/15/2022 at 10:49 PM, Adamw said:

 

[beemn]

right, I added everything from Adams list to the logging and have had the car running and it went into the same fault, hopefully this log has worked!

error 76.llg

[Adamw]

Yep that caught it pretty well.

In the pic below to the left of the pink box I have drawn you can see TP sub and main traces (purple & light blue) are sitting almost smack on top of each other - this is how they should be.  Inside that pink box you can see TP sub - the light blue line starts to drift away from TP main, TP main remains close to target (orange).  Since the RPM didnt change when the TP sub signal initailly drifted up I think we can assume that the TP main is correct (ie throttle hasnt moved), so it is the TP sub signal that is telling lies.  

Since there are no dropouts or spikes like you would commonly see with a loose connection, I would say this is more likely the sensor (throttle body) that is failing.  

[beemn]

Thanks team, finally got the replacement throttle body and after some mucking about got the new one calibrated and after 30min of idling no problems!....so far