P3Cars vent gauge not fully functional with JB4(G5) tune

[kirkbar]

Hey everyone - new to the BMW scene and just installed P3Cars digital vent gauge and it seems to not like the JB4(G5) tune.

The gauge will not display intake air temperature, ignition timing or exhaust temp when my JB4 is on any map but 0 (disabled).

Anyone here have both of these installed and have similar (or no) problems?

I have exchanged a few emails with Rick from P3Cars and he more or less states that the JB4 is aggressively using the Canbus to the point where the gauge can't read the signals.

Was thinking about using one of the gauge's analog wires to hook into the IAT wire from the DME - has anyone here tried this?

Thanks

[c_ozanich]

Welcome to the forums!

I have both of those installed and do not register anything like that. The P3 works great and I always have a read out no matter what Map I run. I can't say that I've read any threads regarding this issue either.

Map 0 is suppose to disable the OBDII ports to register a bone stock read out, it doesn't alter the DME at all. Wiring it directly could work as a bypass around the issue, but I believe there's another issue there that hasn't been found yet. It should function properly because the gauge reads what the OBDII port spits out, and the OBDII port is straight from the DME. I would say something's off with the P3.

I have an n55 engine and my P3 reads the digital outputs, the n54 reads the same way minus the analog boost (vac) line. The issues you are having is with the digital aspect of the gauge. If it's only certain parameters that are not displaying correctly, maybe the pins in the OBDII connection aren't fully engaged? Sometimes if wires get bent/kinked too far the connection will weaken and not send signal

[kirkbar]

Thanks, that's good to know. I'm exchanging emails with Rick from P3 Cars to try to get this worked out. I found if I choose map 0, and then reset the gauge, and then choose another map like 3 or 5, everything on the gauge works but the data displayed seems to lag behind.

I'm also getting random flashing of the turn signals well after my oil heats up above 160F. Did not have this before the P3 install.

I'll check the pins too just in case.

[b1aze]

You cannot communicate through the OBD2 port properly with a JB4 Plug and Play setup on any map other than 0. This is the same reason you have to remove or turn off your JB4 before service or inspections.

[kirkbar]

Originally Posted by b1aze

You cannot communicate through the OBD2 port properly with a JB4 Plug and Play setup on any map other than 0. This is the same reason you have to remove or turn off your JB4 before service or inspections.

So the N55 JB4 harness is not a Plug&Play so I guess that is why it works with MonsterNtheMaking's P3 gauge?

I thought it uses the same canbus method as the N54 JB4 from the description but what do I know?

[b1aze]

The N55 PnP connects to various sensors in the engine bay while the N54 PnP connects inline in the DME connectors. They are different ways of interfacing with the car.

[c_ozanich]

n55 JB4 is straight plug and play--just like the n54. Our plugs are different but the end goal is the same. the CANbus method is the same also. B1aze means that with the JB4 installed, it alters the communication between the sensors and the DME so the OBDII port doesn't provide 100% true information. It shows what the DME is interpreting as true. Any installed piggy back type tuner modifies the sensors in your engine and then intercepts the signal and translates it for the DME. That is how there are no check engine lights when it is working correctly.

Might want to send Terry@burgertuning.com an email also. Your lights flashing could mean you need a firmware upgrade or that there's something off in your settings on the JB4. Mine flashed like that and my gauges (on the dash) would sweep at random intervals during driving. It was weird. Upgraded firmware and cross referenced some threads on n54tech.com and I was set pretty good.


**edit** B1aze explained himself, and I read his wording wrong anyway

[kirkbar]

Thanks to both of you! I'm learning something new every day. Came from the Vw/Audi world where all tunes were ECU flashes with limited options for maps, etc. This is a whole new world!

[Mike@N54Tuning.com]

Originally Posted by ///MonsterNtheMaking

n55 JB4 is straight plug and play--just like the n54. Our plugs are different but the end goal is the same. the CANbus method is the same also. B1aze means that with the JB4 installed, it alters the communication between the sensors and the DME so the OBDII port doesn't provide 100% true information. It shows what the DME is interpreting as true. Any installed piggy back type tuner modifies the sensors in your engine and then intercepts the signal and translates it for the DME. That is how there are no check engine lights when it is working correctly.

Might want to send Terry@burgertuning.com an email also. Your lights flashing could mean you need a firmware upgrade or that there's something off in your settings on the JB4. Mine flashed like that and my gauges (on the dash) would sweep at random intervals during driving. It was weird. Upgraded firmware and cross referenced some threads on n54tech.com and I was set pretty good.


**edit** B1aze explained himself, and I read his wording wrong anyway

The JB4 is not compatible with the p3 gauge OBDII connection. They fight over resources and any data that makes it to the gauge just means your tuning isn't receiving enough of the data it needs to work properly.

Mike

[kirkbar]

Guess it's time to sell one of them which is too bad. I do like the boost somewhere besides my oil or gas gauge.

[Mike@N54Tuning.com]

Originally Posted by kirkbar

Guess it's time to sell one of them which is too bad. I do like the boost somewhere besides my oil or gas gauge.

With the p3 gauge you can use an external manifold sensor so it doesn't need OBDII access. Remember exhaust temperature data is not valid also. There is no sensor for it. The DME just spits out a modeled number which is not accurate once tuned.

Most people run the boost on fuel and then put it on stealth mode so it only shows boost when racing around. Otherwise fuel.

Mike

[c_ozanich]

Originally Posted by Mike@N54Tuning.com

The JB4 is not compatible with the p3 gauge OBDII connection. They fight over resources and any data that makes it to the gauge just means your tuning isn't receiving enough of the data it needs to work properly.

Mike

Interesting... thank you for correcting my knowledge with regards to the n54 engine

[kirkbar]

Just an update on what has been going on with these two products.

When the car is started either the JB4 or the P3 gauge "wins" the battle so to say. If the gauge wins - all metrics are displayed but the JB4 behaves oddly (flashers go off, idle feels wrong) and the numbers on the gauge are very slow to update.

When the JB4 wins - 3 of the metrics do not update - stay at 0 - but the JB4 tune works fine on map 5.

I may just run the gauge off the analog boost and power it by tapping into a 12V source somewhere. It's a bit of a PITA but if the gauge wins - I just need to put it into config mode and exit.

[Everfly]

I had both on my N55 but the only thing i can not get is the digital boost so i have to use the manual boost reading instead but also i dont have the newest JB4.

[Nugget]

I directly asked Rick from P3.

me:I have a 135i with a N55 engine. I recently installed a JB4 and was having some issues.

Terry (who makes the JB4) informed me that the P3 gauge isn't compatible with the JB4 as they fight over CAN data and I would need to leave the gauge unplugged.

He said it might also be possible to set up the P3 so it's not using the CAN lines. Is this possible

Rick:You can change your engine mode to AnLg and that will allow you to use the boost function without canbus.

Me:Thanks Rick,

will using the other functions interfere with the canbus?

Rick: They will use the canbus, yes. The jb4 uses up all the bandwidth, and doesn't like anything else using the canbus diagnostics channel

[kirkbar]

With my N54 they did not play along together. My P3 gauge is for sale on this board for $40 off retail. I should attempt to return it for a refund but Turner states no returns on electronic components?

I think there should be a compatibility statement for both products on their respective sites. If I knew it would not work properly - I would not have bought it.

Example statement:
"This product uses/alters the cars Canbus system and may not be compatible with other after market Canbus devices".

[Joelkswagen]

I recently got an 08 135i N54 with JB4 and P3 hooked up through OBD which seems to be fully functional. It will read out everything such as boost, coolant temp, oil temp... Confused because I am reading a lot about how these two things aren't compatible. Will my car have difficulties with both hooked up? Only issue I have is sometimes the turn signals will randomly flash once, which somehow lead me to this thread.

[Joelkswagen]

Additional note, I installed JB4 Back-end flash through MHD this evening. Prior to doing this the P3 gauge would show the boost the DME was reporting, which was less then actual. Now with the BEF, it seems the boost reported on the P3 is accurate. I.e. Map one on JB4 will read around 14-15 PSI, but prior the BEF it would read around 9. Does anyone know if this is a consequence of having the BEF. Should the boost values from the DME now read accurately?

[xQx]

Wow, way to get an old thread back to life.

The JB4 has changed a lot since 2013. It now automatically detects if something is plugged into the OBDII port and puts its self in pass-through mode.... For the last two years or so it hasn't been necessary to put your JB4 in map 0 to flash your car for this reason. (It's still a good idea... but I can say I've done XHP and MHD flashes many times with the JB4 on map 2).

Critically, the P3 gauge reads what the ECU sees. The JB4 sits between the ECU and the car and modifies ... stuff. So, if you want accurate gauges, use the JB4 mobile app.

That said (and to answer your question directly): Yes.

When you have no Back-end flash, the JB4 lies to the ECU about your boost levels, if it didn't, your ECU would say 'holy crap, my boost is 15psi while I'm targeting 8psi' and throws errors.

When you do the back-end flash, the JB4 stops lying to your ECU and passes through accurate details. The JB4 still controls your boost targets, but your ECU BEF is told what the _actual_ boost is, so that it can manipulate the timing/fueling & tq figures reported to the tcu better. The BEF also turns off all the overboost/underboost warnings because it knows the JB4 is in control of that.
(caveat: I'm not a tuner nor a JB4 programmer, so if you want to know the details go to the n54tech forums and see what you can find there).
So, now with the BEF, your boost levels will report correctly. Your boost target will not.


Your turn signals aren't randomly flashing once, they're flashing when your oil temp reaches 71C/160F. This is telling you that the JB4 has taken over the boost targets, and your car is now 'up to temperature' and using the boost targets set by your selected map. When your car is cold, it uses the stock/ECU boost targets of about 8psi max, once warm, it'll target whatever the map says (Map1: 15psi, Map2: 17psi, Map5:12-17psi, Map7: 18.5psi). The indicator flash can be turned on or off by programming the JB4 via your steering wheel controls (option 6/3IIRC)

[Joelkswagen]

Originally Posted by xQx

Wow, way to get an old thread back to life.

The JB4 has changed a lot since 2013. It now automatically detects if something is plugged into the OBDII port and puts its self in pass-through mode.... For the last two years or so it hasn't been necessary to put your JB4 in map 0 to flash your car for this reason. (It's still a good idea... but I can say I've done XHP and MHD flashes many times with the JB4 on map 2).

Critically, the P3 gauge reads what the ECU sees. The JB4 sits between the ECU and the car and modifies ... stuff. So, if you want accurate gauges, use the JB4 mobile app.

That said (and to answer your question directly): Yes.

When you have no Back-end flash, the JB4 lies to the ECU about your boost levels, if it didn't, your ECU would say 'holy crap, my boost is 15psi while I'm targeting 8psi' and throws errors.

When you do the back-end flash, the JB4 stops lying to your ECU and passes through accurate details. The JB4 still controls your boost targets, but your ECU BEF is told what the _actual_ boost is, so that it can manipulate the timing/fueling & tq figures reported to the tcu better. The BEF also turns off all the overboost/underboost warnings because it knows the JB4 is in control of that.
(caveat: I'm not a tuner nor a JB4 programmer, so if you want to know the details go to the n54tech forums and see what you can find there).
So, now with the BEF, your boost levels will report correctly. Your boost target will not.


Your turn signals aren't randomly flashing once, they're flashing when your oil temp reaches 71C/160F. This is telling you that the JB4 has taken over the boost targets, and your car is now 'up to temperature' and using the boost targets set by your selected map. When your car is cold, it uses the stock/ECU boost targets of about 8psi max, once warm, it'll target whatever the map says (Map1: 15psi, Map2: 17psi, Map5:12-17psi, Map7: 18.5psi). The indicator flash can be turned on or off by programming the JB4 via your steering wheel controls (option 6/3IIRC)

Thank you very much, this helps a lot. A few things I would like to clarify.

1. You say that the JB4 detects if something is in the OBDII port and goes into pass through mode. Wouldn't this mean map 0, with no tune being applied? Maybe you are referring to something else, but to me "pass through mode" means map 0 i.e. JB4 is off. My tune is definitely still active with the P3 gauge connected to OBDII. Also, BMS still advises that you put the car in Map 0 for a BEF flashing procedure... if this is completely necessary, I don't know.

2. You note that the BEF will ignore overboost and underboost warnings. Can you advise if what you are referring to is different than 30FF code (boost not meeting requested?). I have had the 30FF crop up once or twice and I would like to know if the car is still having this issue. I believe due to WG wear, car has some gnarly rattle without WG rattle fix turned on. Would like to know if with the BEF, that code can still be thrown.

I am glad to hear that the P3 should be reading accurately now with the BEF.

As for the single flash of the turn signals, this has been happening long after the car is fully up to temp, at seeming random times. I would need to confirm that setting 6 is not set to flash when the car is at 160*, but it definitely has not been flashing at this point. I have however not see this flash since I updated the JB4 to 32.12 last week.

Thanks again, and apologies if this is

[xQx]

Originally Posted by Joelkswagen

1. You say that the JB4 detects if something is in the OBDII port and goes into pass through mode. Wouldn't this mean map 0, with no tune being applied? Maybe you are referring to something else, but to me "pass through mode" means map 0 i.e. JB4 is off. My tune is definitely still active with the P3 gauge connected to OBDII. Also, BMS still advises that you put the car in Map 0 for a BEF flashing procedure... if this is completely necessary, I don't know.

Yes, They don't make public the exact logic, and I'd say not many people are doing what you are (using both the JB4 and another ODBII device). They also still advertise that you should put it in 0/0 before flashing.

Back in the day if you did a MHD or BB flash with the JB4 in anything but 0/0, you would get a very corrupt ECU. (requiring a reflash). BMS fixed this, and you can now, pretty reliably, plug in your MHD with the JB4 on map 2 and flash without issue. Maybe it only puts its self in passthrough mode when it detects something plugged in and the engine is off, maybe it isn't detecting your P3 gauge and the only 'incompatibility' is that the P3 gauge reads the ECU and the JB4 sometimes makes these values inaccurate (ie. boost target will almost always be wrong).

Now, if you're using NCSExpert to re-flash your iDrive unit, I would 110% recommend putting the JB4 in map 0. I have flashed my car many times with the JB4 set to map 2, but this week when I did a long (40min) flash back to stock then back to BMS backend I manually set it to map 0 because I wanted to be sure it wouldn't mess up.

No doubt it's safer to set it to map 0, and some people are running very old firmware - so if you're doing anything remotely risky - set it to map 0. However, I am saying with absolute certainty, this is actually something you don't have to do for your XHP or MHD flash, but you should.

Originally Posted by Joelkswagen

2. You note that the BEF will ignore overboost and underboost warnings. Can you advise if what you are referring to is different than 30FF code (boost not meeting requested?). I have had the 30FF crop up once or twice and I would like to know if the car is still having this issue. I believe due to WG wear, car has some gnarly rattle without WG rattle fix turned on. Would like to know if with the BEF, that code can still be thrown.

Ah ha! A question I'm in a uniquely qualified position to answer. Yes, the BEF absolutely suppresses 30FF. If you have a N54, you should diagnose that code and find out to your satisfaction what is causing it. We have two turbos but only one boost sensor. If you have one wastegate closing and one remaining open, one of your two turbos will be doing much more work than the other, and potentially much more work than it was designed for. If that's the case, it'll wear out prematurely and you'll be up for a $4k+ turbo replacement job. (I dare you to ask me how I know this )

The good news is that might've been being caused by your JB4 giving fake values to your ECU. But you will want to know for sure.

There are two ways you should diagnose this issue. Just driving around and being happy there are no codes on the dash isn't good enough, especially if this is a relatively new car to you and you can't 'feel' if it's working in perfect order.

If you have the USB or Bluetooth interface to your JB4, your best way to diagnose it is to set it to map 4, start logging, then go as slowly as you can in third gear and push the throttle to the floor and keep it there until redline. (you'll be speeding by redline, so do this on a private road ). Then, submit the log to the 'log review' section of the n54tech forums. They will be able to tell you if it is building boost properly. If it all looks good, repeat the process on map 1 or map 2 depending on your mods.

If you can't get a log from the JB4, I would flash back to stock, set the JB4 to map 0 then drive hard and see if you get the code (same process should do it - foot to the floor in third gear until redline). If you do get 30FF on a stock tune with the JB4 on map 0 - I'd get that checked out ... it could be nothing (hopefully it is)... but it could also be why your previous owner sold the car.

Originally Posted by Joelkswagen

I am glad to hear that the P3 should be reading accurately now with the BEF.

As for the single flash of the turn signals, this has been happening long after the car is fully up to temp, at seeming random times. I would need to confirm that setting 6 is not set to flash when the car is at 160*, but it definitely has not been flashing at this point. I have however not see this flash since I updated the JB4 to 32.12 last week. Thanks again, and apologies if this is

Last thing first - not a repost .. and even though you did bring a 5 year old thread back from the dead, you'll likely not be the last person to have some of these issues.

The JB4 flashes its indicators to you for a number of reasons, and BMS will always say upgrade to the latest firmware before trying to diagnose anything... In the latest version, the most common reasons your indicators flash are:

• If you've got the shift-light setting, the indicators turn on solid as your 'shift light' at high revs.
• If you have warm-up flash set, it flashes at 160f
• If you trigger a JB4 safety (generally speaking - overboost, or any condition which means the JB4 can't gaurantee enough fuel is getting to the engine (two things that can cause 'rapid unintentional disassembly' of a N54), the JB4 will flash indicators to you and switch to map 4

If it's gone away with the latest firmware, I'd think nothing more of it. If it hasn't, first check that you're not switching to map 4 for some reason.