JB4 satety code 5 = fuel trim variance

Bongo

Specialist
Feb 22, 2018
61
54
0
Ride
E92 N54 335i
So since last week my N54 won't go out of the safety map.
I completed my single turbo project a few weeks ago and started getting O2 related codes and JB4 safety map, so i replaced them with NTK O2 sensors.
Problem is, that my JB4 still goes into safety map the moment i turn it on. (Even with the engine off)
JB4 tells me it's a safety code 5 = Fuel trim variance.
I already flashed it back to stock to see if it's tune related, but still occurs when i turn on the JB4.
Does this mean my injectors are probably done?
Car still has a stock LPFP and no port injection, only on pump + wastegate spring so far with a BMS backend flash.
Thanks.
 

doublespaces

General of the Army
Oct 18, 2016
8,945
4,152
0
AZ
Ride
2009 E93 335i
Hello Bongo! I'm glad to see you're using the Question format where people can vote on the best answer and you may select a solution!

I would guess @[email protected] might have an answer for you.
 

Bongo

Specialist
Feb 22, 2018
61
54
0
Ride
E92 N54 335i
Hello Bongo! I'm glad to see you're using the Question format where people can vote on the best answer and you may select a solution!

I would guess @[email protected] might have an answer for you.
Thanks, already mailed him few days ago and told him i'd make some WOT logs.
At idle and low load everything seems fine..
I'm just waiting for a friend to show up one of these days so we can check out my injector values and things.
 

Rob09msport

Major
Oct 28, 2017
1,928
662
0
Monroe CT
Ride
09 335i msport le mans 18 x5
I was told that valve cover leaks can cause fuel trim variances idk how but was reliable source.
 

Bongo

Specialist
Feb 22, 2018
61
54
0
Ride
E92 N54 335i
I was told that valve cover leaks can cause fuel trim variances idk how but was reliable source.
That's good news, i was about to replace that, already have the gasket and new NGK plugs.
 

Bongo

Specialist
Feb 22, 2018
61
54
0
Ride
E92 N54 335i
Ever find the answer?
No, haven't been looking for it either.
Still have to order index 12's, kind of a expensive "maybe".
And weather has been really bad here so didn't have a opportunity to log WOT..
Can't find any similar problem on the internet regarding the "Last safety 5, fuel trim variance".
I just find it weird that it seems to be stored inside the JB4. Like if it's reading some kind of error code automaticly triggering safety map with the engine off for more than a week.
 
  • Funny
Reactions: doublespaces