Hi all,

I have a strange issue that has just started and I need some help to figure out what's going on. Been doing a lot of searches and I have some idea but things don't add together well.

Here is the back story:
- car has been parked for about 1 month waiting for some parts
- during this time I fixed 1 brake line and did a brake bleed for that corner
- during this time I also replaced a broken tail light and used an LED tail light
- during this time I also installed 3mm wheel spacers at the front wheels
- my tire sizes are not matching very well but this has been the case for the last 5k+ miles (235/35/19 fronts and 295/30/19 rears)

The issue:
- I get a PSM/ABS error message on dash
- warning lights disappear after I re-start the car
- DME code read by Durametric is P0571 (brake switch: signal implausible)
- warning light appear at 75mph (without touching the brake) at the same time that the spoiler raises
- no issue at all as long as I stay under 75mph





Note that my cheap cable running durametric 3.0.15 SW version cannot read the actual ABS/PSM module

 

Check your brake light switch usually the culprit.

 

yes it seems to be the most common root cause and it could be that my wife pressed the pedal too hard as we were bleeding the brakes, but then the question is why would it show up only at 75mph and without me braking?

 

I've also read that a MAF issue can cause this condition.

I have the issue intermittently, but I've been too lazy to troubleshoot it. Now that the car is back together (I finally got the GT3 console delete finished), I'll move on to this issue.

 

Interestingly, I see this most often when I'm at idle for a while - for example, waiting for my wife at the Nissan dealership a while back. This was the same pattern I saw when my MAF was going bad last time around...

 

yes I read MAF several time and I thought this was it as it's supposed to come under hard acceleration first, but then I tried accelerating slowly to 75mph and still get the issue.

Would be completely random that MAF issue is coming now when I have tinkered with all those other things that could be related, but I guess I should keep that in mind.

 

ok, just had an idea and went for a test drive. at 40mph, if I push the manual spoiler button (down by my foot), I get the same error.

so definitely something to do with the spoiler, I think that means it's not the MAF nor an alignment issue.

I don't get the spoiler warning light which I would expect... wonder what to do next now

 

How old is your battery? I vaguely also remember something about a failing battery being at fault for someone's PSM/ABS fault, and since deploying the spoiler draws a decent amount...

 

was thinking the same... especially since another mod I have is a BigCrank ETX14L that's about a year old.

It got pretty low while the car was parked, maybe that's the issue.

Will try swapping the battery tonight see if that helps

 

I'm thinking all of the above....

The one that sticks in my head though is the one you didn't mention in the poll. You removed a brake line than bled. Did you purge the entire system or just that corner?

 

was a bit lazy and did just that corner (rear left)... I guess I should have done at least the rear right as well.

 

I would suggest you bleed all corners. RR, LR, RF and LF in that order. If you don't have a Motive Power Bleeder you should get one. Its a one person diy.

Also you have a Durametric right? I would activate the brake booster and bleed it at the RF.

Just some thoughts...

 

Did you use a whole LED taillight assembly or just a bulb?

Try taking out the LED tail light and see if things go back to normal.

 

Did you change the brake light switch yet? It is cheap and takes 5 minutes to do. Start with that.

 

If MAF, then you'd get P0115 and P5525.

I'd say either brake light switch or -most likely- led brake lights. Did you install aux resistors with led bulbs? If not, please do so. I have not got any warnings with leds and resistors. When installing I made a test without resistors...and installed them right away...