Random e-throttle faults - tracking error

[AEWON]

Hi all, I have recently had a weird and random e-throttle issue, vehicle has been recently tuned and no issues previously. 

 

Sometimes when I first start it, it will go into safety mode and throw a code 76 TPS tracking fault code and looking through live data it seems to be the Main TPS side percentage will race upto 100 percent ( I’ve even watched it randomly on its own move up and down) while the Sub TPS will always  read around 6.5 percent with the ignition on , on a good day I’ll clear the fault code and restart the vehicle (maybe carry out a throttle relearn) and both main and sub will read around 4.5 to 6.5 percent when running at cold start idle, can drive it for the day and no issues, on a bad day it won’t clear (it’s always on cold start ups I’ve found but it doesn’t get driven much)  and it’s a 50/50 chance that recalibrating the e-throttle will sort it. I’ve checked wiring and even repinned and fitted another new connector for the throttle body and even when swapping Main and Sub wires over at the plug harness, the fault still appears on the Main TPS side, I’d normally think throttle body is the issue, but it’s a brand new bosch 60mm direct from bosch motor sport Australia, it could be faulty out of the box....but seems unlikely , so I’m a little stumped as to what other influences might have on the e-throttle to cause a tracking fault, its a plug in S13 76pin G4+ that’s had an ECU modification at Link across the lmain board to suit e-throttle. Using factory sheilded Main TPS wire and another from the XS loom for sub. 

 

I’ve also had the throttle body percentage stick at 6.5 percent on a start up, idle will fluctuate a little, no fault code, but pressing accelerator and no movement from the throttle body, I can see the pedal voltage changing in runtime values, but no throttle change , I’ll carry out a recalibration (sometimes it takes several attempts) to ecu , save it and then it’s fine for a few start ups until it randomly faults again. 
 

Any thoughts? 

[Adamw]

Will need to see a log of the TPS error to see if there are any clues.  Do you have plenty of margin between normal TP voltage and the values you have set as error values?

 

52 minutes ago, AEWON said:

I’ve also had the throttle body percentage stick at 6.5 percent on a start up, idle will fluctuate a little, no fault code, but pressing accelerator and no movement from the throttle body, I can see the pedal voltage changing in runtime values, but no throttle change , I’ll carry out a recalibration (sometimes it takes several attempts) to ecu , save it and then it’s fine for a few start ups until it randomly faults again. 

That sounds like it has been disabled, 6.5% is about where the spring pushes the blade to with most throttles when unpowered.  

[AEWON]

I didn’t tune the car, just built it, but set some of it up to be able to start and send it for a tune.

I’ll wait for it to fault again and can record a log and I’ll post it up.

can screen shot the margins for you to see? Or easier sending the map? Not currently at the vehicle but it’s at work 

[Adamw]

attach the map.

 

[AEWON]

cold start throttle issue.llg

 

heres a log of the fault , cold start and idle.

 

is there an easy way to pin point what map i have loaded? I have 3 different maps in the directory from the tuner and there all a similar date.

map file attached 

NISSAN S14.pclr

[Adamw]

The fault happened before you started logging so cant see what caused it.  Since you have tried swapping the sub/main pins at the throttle end, I would next try changing the TP sub/main assignments in the software (so main is on AN V 11), that will show if it is a wioring issue at the ecu end or possibly a bad internal connection.

 

40 minutes ago, AEWON said:

is there an easy way to pin point what map i have loaded? I have 3 different maps in the directory from the tuner and there all a similar date.

Yes, connect to the car, then use the file compare function, it will highlight anydifferences betwwen the ecu and the map you are comparing.  You may also get a vauge idea which is more recent by looking at the "engine starts" parameter in the ecu statistics.  

[AEWON]

Cool, I’ve re assigned Main and Sub, cleared faults and recalibrated the e-throttle, all working as normal . The fault only seems to happen on a new key cycle/ re start and will never fault during a drive. I’ll just wait for it to re fault and see if it shifts to Sub or stays on Main.

Thanks for the help.

 

[AEWON]

Ok so after leaving it for nearly a week, start up and its instantly faulting, switching AN outputs over and the fault moves with the output, ive then switched the wiring and the fault hasnt shifted, switching the AN outputs back and the fault shifts back, so at a guess thinking it might be ECU related? Im in Auckland, would it be worth while sending the ECU back for testing?

 

Cheers

[Adamw]

Can you clarify that statement... 

So you changed AN V 11 in the software to TP main and AN V5 to TP sub, but it is still AN V5 which is going to 100% at power up?

Then you swapped wires and it was still AN V 5 going to 100%?

[AEWON]

Sorry for not being clear enough, I switched the software AN V5 TP main (which was faulting) to AN V11 TP sub and vice versa and the fault moved from TP Main to TP sub, switched the TPS wiring at the throttle body around (main to sub and sub to main ) and the fault was still present on AN V11 TP Sub, I then switched the software back and the fault moved back to AN V5 TP main  

[Adamw]

Now im even more confussed.  So it cant be internal then if you get the fault on both ANV5 and ANV11.  If it was internal it would always be the same ANVolt pin that plays up.  

[AEWON]

All good, just doing what you asked me to try, guess it must be a wiring issue or the new throttle body is at fault.

 

[AEWON]

So just an update on this, I re wired all the e throttle including new pins at the ecu and replaced the throttle body with another new bosch item and once recalibrated it’s fine.

As soon as I flick the main power fuse off in the boot to disconnect the battery and switch it back on, when the ecu powers up it’s going straight into limp mode, the e throttle faults (now a code 70 %DC) and as soon as I recalibrate the e throttle it’s absolutely fine again it has no drivability issues or e throttle faults, it’s only on an ecu power up cycle.. I’m at a loss as to why this would be happening 

[Adamw]

Can you set up ecu logging to log all e-throttle related stuff and give us the log after this event occurs.

[AEWON]

5 minutes ago, Adamw said:

Can you set up ecu logging to log all e-throttle related stuff and give us the log after this event occurs.

Unfortunately it’s faulting as soon as the ignition is on so the log is only going to show you limp mode default settings for the e throttle I’d say?   
 

I’ve been looking at run time values and the tps main and tps sub percentages sit at 6% when it’s been calibrated at key on engine off as soon as I flick the kill switch off and on, they instantly hit 90% key on engine off, I then have to recalibrate and the go back to 6%, I’m not sure how to log this as the ecu will be powered down 

 

[Adamw]

You can set up the ECU log to record anytime the ecu is powered so that will likely capture more than you are seeing on the screen.  Also I would try logging a power cycle with it in setup mode too as that will not allow it to go into safety mode.