JB4 + Check Engine Light

[racer_x]

Hi All,

I installed a JB4 yesterday (no other mods thus far)... I took the car for a "spin" on map 5 for about 40 minutes and all was well.

I was driving home from work just now and the Check Engine Light came on (yellow) which according to the manual means "full power is not available".

This happened at about 4,000-4,500 RPM under hard acceleration. Not quite WOT. Probably 70-80%.

I turned the engine off and back on and the light went away.

I then proceeded to push again when traffic allowed and managed to replicate the issue.

The thing is, I had the JB4 on map 0 for the drive home given I was in Sydney traffic which puts the JB4 in bypass mode.

The car has 68,000 kms on the odometer and I can't find any records of the spark plugs ever being replaced in the set of invoices I was given when I bought it. So it will be back to Advan for a quick pit stop next week to change those.

The original HPFP and injectors were replaced under warranty back in 2010 @ 45,000 kms.

What else should I look out for? Coils?

Also, is there a way of getting the error code being thrown when the light comes on through Check Control? My car does not have iDrive unfortunately and I haven't got the BMS cable to do any logging if I was to turn the JB4 back on.

Thanks in advance.

[Knightelf]

Do you feel anything wrong with the car except for the CEL? If the car drives fine it could just be JB4 tuner codes which is normal. If so, just turn on autoclear codes on the JB4 to ignore.

You can check for codes using the JB4 controls (can't remember what the menu option is). Once you know the code you can google to find out what it is.

[Zen]

Originally Posted by racer_x

Hi All,

I installed a JB4 yesterday (no other mods thus far)... I took the car for a "spin" on map 5 for about 40 minutes and all was well.

I was driving home from work just now and the Check Engine Light came on (yellow) which according to the manual means "full power is not available".

This happened at about 4,000-4,500 RPM under hard acceleration. Not quite WOT. Probably 70-80%.

I turned the engine off and back on and the light went away.

I then proceeded to push again when traffic allowed and managed to replicate the issue.

The thing is, I had the JB4 on map 0 for the drive home given I was in Sydney traffic which puts the JB4 in bypass mode.

The car has 68,000 kms on the odometer and I can't find any records of the spark plugs ever being replaced in the set of invoices I was given when I bought it. So it will be back to Advan for a quick pit stop next week to change those.

The original HPFP and injectors were replaced under warranty back in 2010 @ 45,000 kms.

What else should I look out for? Coils?

Also, is there a way of getting the error code being thrown when the light comes on through Check Control? My car does not have iDrive unfortunately and I haven't got the BMS cable to do any logging if I was to turn the JB4 back on.

Thanks in advance.

Pete recommends Spark Plugs every 25,000 km and Coils every 50,000 km for a tuned N54. Probably get both done at that mileage and at the same time to save yourself a bit of labours, but if you are tight then just get Spark Plugs done for now, and do the coils at your next oil service.

[racer_x]

Originally Posted by Knightelf

Do you feel anything wrong with the car except for the CEL? If the car drives fine it could just be JB4 tuner codes which is normal.

It doesn't feel down on power.

I found this thread which shows how to read the codes through the dash [http://www.n54tech.com/forums/showthread.php?t=11495]. So will check tomorrow morning.

What are JB4 tuner codes? Is it the stock ECU detecting the JB4 and complaining?

What else would auto code clear blow away? I don't want to go sweeping codes under the carpet if I don't have to.

[JB4-335]

Change your plugs ASAP.

My car has only 35k on the clock and I'm on my 3rd set of plugs.

[racer_x]

Originally Posted by Zen

Pete recommends Spark Plugs every 25,000 km and Coils every 50,000 km for a tuned N54. Probably get both done at that mileage and at the same time to save yourself a bit of labours, but if you are tight then just get Spark Plugs done for now, and do the coils at your next oil service.

Thanks Zen. Might do both while we're at.

What would coils cost?

[Zen]

Originally Posted by racer_x

Thanks Zen. Might do both while we're at.

What would coils cost?

I asked Stu a few wks back, it was $60 each.. x 6 = $360

[froop]

To be honest, sounds like it could be the HPFP. Even new versions can fail. How are your morning cranks? Longish?

[racer_x]

Originally Posted by froop

To be honest, sounds like it could be the HPFP. Even new versions can fail. How are your morning cranks? Longish?

It starts first time every time.

I managed to read the error code through the dash using the instructions here: http://www.e90post.com/forums/showthread.php?t=876049.

It reads 2099 to my eye.

I could not find the error description anywhere on the n54tech forum but a Google searched found this http://www.datsc.com/tabid/122/OBD-E...W/Default.aspx

Is this correct? "Post Catalyst Fuel Trim System Too Rich"

If so, what am I replacing first?

[Zen]

Originally Posted by racer_x

It starts first time every time.

I managed to read the error code through the dash using the instructions here: http://www.e90post.com/forums/showthread.php?t=876049.

It reads 2099 to my eye.

I could not find the error description anywhere on the n54tech forum but a Google searched found this http://www.datsc.com/tabid/122/OBD-E...W/Default.aspx

Is this correct? "Post Catalyst Fuel Trim System Too Rich"

If so, what am I replacing first?

http://forums.bimmerforums.com/forum...re-Help-Advice

hope this helps.

[racer_x]

Originally Posted by Zen

http://forums.bimmerforums.com/forum...re-Help-Advice

hope this helps.

Thanks Zen. I saw that but the car in that thread was a 2004 325i so I didn't really know what to make of it.

Just thinking out loud here but could a misfiring spark plug or a bad coil cause the air fuel mixture to run rich (unburnt fuel) and cause this error?

Then again, wouldn't a misfire be reported as a different/more obvious error code?

The only other thing I can think of would be a bad O2 sensor. Correct me if I am wrong but those usually don't die before 100,000 kms.

The car feels fine apart from the warning light!

[drjekl]

Based on my experiences, a fresh set of plugs and coils should be installed in conjunction or prior to the tune!

It just makes it so complicated when you get your tune, and start getting CEL's when 90% of the time its plugs or coils being the issue.

[racer_x]

Hi Guys,

Thanks to all those who responded. It's what makes this forum great.

It turns out I was reading the error code wrong. The actual error code was 30FF : Boost under target - possible boot leak.

In case anyone has the same issue in future and is running on the G5 ISO, I found the following thread on the n54tech forum: http://www.n54tech.com/forums/showthread.php?t=19021

The takeaway from this is the bit highlighted in red in post #4:

5) Map 0 is no longer a true pass through map. It disables the JB4 and targets 7psi across the board. On map 0 the car will drive and operate normally, can be taken to the dealer, reflashed, etc. But extended WOT runs on map 0 may result in a 30FF underboost code. Map 4 targets OEM boost values and should be used for dyno comparisons, driving around stock, etc.

So it seems that Map 0 is no longer the true "back to stock" tune...

BMS confirmed that the 30FF error can be cleared and ignored on Map 0. They also recommend running on Map 1 for stock cars and not Map 5.

I drove into work this morning on Map 4 because I've still got some 95RON fuel that was in there before the JB4 was installed... So far so good.

[135iam]

I suggest you stick with maps 1 , 4 and 5. I have logged them all with my stock 2010 n54 with no issues.

One thing I have read from Terry@bms is to not change maps too often as it takes several pulls to "adapt/learn" the new tune. Every time I change maps I do a three 2-6K rpm pulls back to back for the learning part to complete (as instructed on n54tech)

Once you can log, try 35% E85 on map 5. It'll put a smile on your face stock fuel pumps vary so start at a low percentage, but I can use 50% E85 with no issues and 50% 93 octane and see a peak of 16.7psi (all else stock) in 3rd and 4th.

Even if you can't get e85, higher octane will make more power on a stock car with map 5 over map 1 for sure.

[Zuzu]

Also... I wouldn't even run 95RON on a standard N54, let alone a tuned engine.

[135iam]

Oh, just read 95RON is US 91 octane, yeah that's not good for a tune. I utilize between 93-100 octane only, which if I did my math right is between 98-105 RON
.

[kaitan]

Originally Posted by racer_x

Hi Guys,

Thanks to all those who responded. It's what makes this forum great.

It turns out I was reading the error code wrong. The actual error code was 30FF : Boost under target - possible boot leak.

In case anyone has the same issue in future and is running on the G5 ISO, I found the following thread on the n54tech forum: http://www.n54tech.com/forums/showthread.php?t=19021

The takeaway from this is the bit highlighted in red in post #4:

5) Map 0 is no longer a true pass through map. It disables the JB4 and targets 7psi across the board. On map 0 the car will drive and operate normally, can be taken to the dealer, reflashed, etc. But extended WOT runs on map 0 may result in a 30FF underboost code. Map 4 targets OEM boost values and should be used for dyno comparisons, driving around stock, etc.

So it seems that Map 0 is no longer the true "back to stock" tune...

BMS confirmed that the 30FF error can be cleared and ignored on Map 0. They also recommend running on Map 1 for stock cars and not Map 5.

I drove into work this morning on Map 4 because I've still got some 95RON fuel that was in there before the JB4 was installed... So far so good.

If boost is leaking you wouldnt have any power at all dependson how the boost leaks I had this issue recently and I thought it was HPFP failure coz the car with or without the cell error it just runs like a N/a car without any boost. It turns out to be 2 turbo hoses crack so I change them and it's all good.

[kaitan]

http://www.e90post.com/forums/showthread.php?t=940526 read this.

[racer_x]

Originally Posted by Zuzu

Also... I wouldn't even run 95RON on a standard N54, let alone a tuned engine.

Totally agree. I was in woop woop, low on fuel and 95 was all they had.

[Knightelf]

Originally Posted by kaitan

If boost is leaking you wouldnt have any power at all dependson how the boost leaks I had this issue recently and I thought it was HPFP failure coz the car with or without the cell error it just runs like a N/a car without any boost. It turns out to be 2 turbo hoses crack so I change them and it's all good.

The boost leak code for the OP is not actually a boost leak. Map 0 on N55 ISO is not meant for driving and will throw a code over 4k rpm (this is probably the only "bad" part of the N55 ISO - there is no true bypass map).

OP - glad you have it sorted out, regarding your question on autoclear, it doesn't clear any real codes (if something is actually broken) as it's just intended to clear the tuner codes and DP codes (when you install aftermarket DP) etc.

[Zuzu]

Originally Posted by racer_x

Totally agree. I was in woop woop, low on fuel and 95 was all they had.

Fair enough mate... We have all been in that situation.

[racer_x]

Originally Posted by Knightelf

OP - glad you have it sorted out, regarding your question on autoclear, it doesn't clear any real codes (if something is actually broken) as it's just intended to clear the tuner codes and DP codes (when you install aftermarket DP) etc.

Cheers for that.

I have to say BMS support was very good too. Surprisingly so, given that they must answer the same old set of questions EVERY day.