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Fuel Pump Controller Options/Upgrades (this is gonna be a long one...)

arob157

Go Kart Newbie
Location
USA
Hello all you cats and kittens in MQB land! I think I am traveling down a solid path here. First, I want to qualify the following information with the fact that I have done zero testing on this, nor have I verified pinouts/wiring. I have ordered one of each variant and will be trying to track down the wiring diagrams for the options I have discovered. There are other load concerns with wire gauge in the stock harness as well. That could be overcome by using an empty 12V fuse location and using larger gauge wire and repinning the stock connector (as is done with other controllers such as the PM4).

One of the challenges faced when upgrading the stock LPFP is having to restrict the LPFP duty to limit the current draw so as to not burn up the stock MQB controller. I was previously triggered by two different brushless pumps: The Iroz and PAGParts units both pictured below:

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MQB_Brushless.png


Turns out the Iroz controller is from an older Tiguan and the PAGParts is from a RS3/TTRS (4M0906093N). The Iroz uses a custom harness and the PAGParts uses a jumper harness to convert from 7-spade to 5-spade to mate with the stock harness.

It wasn't until yesterday that I I have been thinking that there is no reason that VAG would produce exclusive connectors and controllers across every single platform. Turns out, that is correct. So far I have discovered variants with 3-spade, 5-spade, and 7-spade receptacles. The stock MQB controller is a 5-spade. When researching allowable current loads on the stock controller, I have seen anywhere from 15-17 amps referenced as the limit. The stock fuel pump controller/driver has a 15 amp fuse in the fuse box (stock controller shown below).

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So I started doing some digging. Got on the good old Audi Parts USA website.In my quick search, I found two variants that look to utilize a similar connector. The first is for 2015+ Q3s and Tiguans. Part number: 5N0906093B. Crossreferencing the fuse chart for an Audi Q3 shows a 25A fuse and for a VW Tiguan shows a 20A fuse.

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The second for Audi R8 / Q7s. The part number is: 4F1906093B. Crossreferencing the fuse chart for an Audi Q7 shows a 30A fuse.

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At the end of the day, we will see what happens. I have a spare LPFP that I was going to chop up for my PR 525 kit. For now I am going to experiment on the stock LPFP and see if any DTCs arise. I will still utilize the stock, 15A fuse and wiring.

I know I might be crazy, but the rabbit hole was too tempting not to dive into head first. Let a guy know if he is crazy and please by all means, help shed some light on if this may be doable.
 

Mosquito

Ready to race!
Location
FL
I always wondered why SB10 fuse was 15A in NA and 20A in ROW MPI enabled cars.
It pertains to the J538 Fuel Pump Control Module. The J17 Fuel pump relay remains at 10A regardless.

I don't know if the ROW controller is a different part#, but if VW went from 15A to 20A is because clearly the pump needed more juice to power up the other 4 injectors with enough fuel to surpass the 15A and they felt they could safely work the controller up to 20A. First line of defense is a fuse, so they wouldn't risk putting a 20A fuse on a controller that would otherwise burn out at 17A. Only I would do such foolish things.

Thanks for looking into this. I'll follow this closely.
 

Gvazquez

Go Kart Newbie
Location
North Carolina
You might be on to something genius here. You might have to tune out some lpfp speed codes is all I see wrong
 

arob157

Go Kart Newbie
Location
USA
Any idea what size/gauge the stock power/ground wires are?
I am not sure, but will measure them to check and see. I may have a cut, stock connector on the spare LPFP I have.

I always wondered why SB10 fuse was 15A in NA and 20A in ROW MPI enabled cars.
It pertains to the J538 Fuel Pump Control Module. The J17 Fuel pump relay remains at 10A regardless.

I don't know if the ROW controller is a different part#, but if VW went from 15A to 20A is because clearly the pump needed more juice to power up the other 4 injectors with enough fuel to surpass the 15A and they felt they could safely work the controller up to 20A. First line of defense is a fuse, so they wouldn't risk putting a 20A fuse on a controller that would otherwise burn out at 17A. Only I would do such foolish things.

Thanks for looking into this. I'll follow this closely.
From what little I can gather about the ROW parts, they seem to be the same controller and sender. No one seems to ever upgrade the sender or relay. I imagine the relay is simply switched on with the ignition. And has a 10A internal fuse so it doesn't fry an inline component from in-rush current. I do see that the two options listed for the fuse are based on the specified alternator (generator) amperage spec. Looks to be 90/140/1XX alternators available.

You might be on to something genius here. You might have to tune out some lpfp speed codes is all I see wrong
We will definitely see. I have poked around on the Eurodyne code tables a bit, so if I throw a LPFP speed code, I can lower the warning level or potentially disable the code.

I honestly just wanted to find a less expensive option. eBay has a metric crap load of these controllers. They are anywhere from $40-150. Like I said, my biggest concern is the wire gauge. I will identify both the gauge and spec of the stock wire (load / temp capability). I will also post the connector PN.
 
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EvoFool

New member
Location
Oregon
Car(s)
‘03 Evo 8, ‘18 R
I love what you are researching, I’m currently hung up on what I want to do for a LPFP.

Is you idea to use a Part’s Bin controller as a substitute for a PM4? I thought I read on here somewhere that the brushless kits are all using the Ti BKS1000...? I was trying to figure out the dimensions of the BKS1000 but I‘m not sure if will fit in the basket and it needs a check valve added to it.

I was wondering if adding a check valve to the 295 pump would be a better long term solution than running the 285(525 Hellcat pump) that draws a ridiculous amount of current.

Maybe all of this has been covered on here somewhere already but I’m useless when it comes to the search function.
 

The Dude

Go Kart Champion
Location
PNW
I love what you are researching, I’m currently hung up on what I want to do for a LPFP.

Is you idea to use a Part’s Bin controller as a substitute for a PM4? I thought I read on here somewhere that the brushless kits are all using the Ti BKS1000...? I was trying to figure out the dimensions of the BKS1000 but I‘m not sure if will fit in the basket and it needs a check valve added to it.

I was wondering if adding a check valve to the 295 pump would be a better long term solution than running the 285(525 Hellcat pump) that draws a ridiculous amount of current.

Maybe all of this has been covered on here somewhere already but I’m useless when it comes to the search function.
Pagparts is your cheapest brushless option. It will fit in the basket, thats what they use. I dove reeeeeeal deep on this one Morty, and I'll save you the time. The E5LM (Veyron/X5M pump) is what pagparts and iroz both use. Pagparts has theirs around 400 dollars cheaper. Torqbyte is prototyping a brushless controller and I'll do an unboxing/review when I get them.
 

arob157

Go Kart Newbie
Location
USA
I love what you are researching, I’m currently hung up on what I want to do for a LPFP.

Is you idea to use a Part’s Bin controller as a substitute for a PM4? I thought I read on here somewhere that the brushless kits are all using the Ti BKS1000...? I was trying to figure out the dimensions of the BKS1000 but I‘m not sure if will fit in the basket and it needs a check valve added to it.

I was wondering if adding a check valve to the 295 pump would be a better long term solution than running the 285(525 Hellcat pump) that draws a ridiculous amount of current.

Maybe all of this has been covered on here somewhere already but I’m useless when it comes to the search function.
I wouldn't call the controllers "parts bin" as opposed to "readily available" either used or direct from Audi or VW and brand new. They manufacture vehicles with turbo I-5, supercharged V-8, V10 and V12 motors. All of which required significantly more fuel (and some of which run brushless fuel pumps). They also sell vehicles in parts of the world (Brazil, etc) that run high ethanol content fuel. Obviously those pumps do not fit our configuration/tank, but it would be crazy to have electronics & different mechanical cases designed for every single individual fuel pump. They want to order large quantities and cut as much cost as possible.

As you pointed out, the purpose of the PM4 is to allow the significantly higher current draw that the higher flow pumps require when running high ethanol contents. As my preliminary research shows, the two controllers listed above run 25 & 30A fuses in their fuse boxes. I would imagine it is safe to say that based on this knowledge, that the controllers themselves can handle 25 or 30 Amps (and would be designed with suitable headroom).

I have received both the R8/Q7 and Q3/Tiguan controllers with the chopped harness & connector. The pinout is identical. Wire gauge is as well. Measuring the wire came up with 2.5mm diameter (internal copper wire diameter). I haven't ordered or measured the stock MQB harness, but the wires look to be 1.0-1.5mm. I do believe it would still be prudent to run power back to the controller and potentially direct to the pump (although I find it interesting that Precision Raceworks nor the brushless options modify the stock harness in any way). The connector part number is: 6N0 973 755. There are a ton of websites that sell pre-crimped repair wire, the required terminals, de-pin tools etc. I am going experiment with the Q3/Tiguan controller first as I believe it will fit the stock location/mount.

In regards to the 525 pumps, if you compare the charts for each pump, the 285 variant maxes out around 24.80 amps, and the 295 variant maxes out around 23.00-23.50 amps. Initial current looks to be the difference between 16 amps for the 285 and around 13 amps for the 295. So initial load is a decent bit lower.
 
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yirayira

Go Kart Newbie
Location
Lancaster, PA
arob157 great work and please keep us updated! Running a 285/295 to it's full potential with an OE controller would be an ideal solution to going brushless (y)
 

The Dude

Go Kart Champion
Location
PNW
Those pumps you mention both pull a ton of current. The brushless pump only pulls around 18 amps at full rip.
 

yirayira

Go Kart Newbie
Location
Lancaster, PA
Those pumps you mention both pull a ton of current. The brushless pump only pulls around 18 amps at full rip.
Is it too much current for the Q7/R8 controller with a modified harness? I'm curious how much flow we could get out of an inexpensive diy brushed solution
 

The Dude

Go Kart Champion
Location
PNW
I'll be honest, I feel like it'd be fine with the stock controller. Put a 20 amp fuse in and call it good, you're not gonna pull that much power. Looking again, the chart stops at 14 amps, over 100 PSI fuel pressure, if you look at the curve from the data they have, it'll flow 445 lph at 105 psi. It's a crazy amount of fuel. I should literally never ever run out of LPFP. And it's brushless, so hopefully it lasts a really long time.

Radium Pump Comparison
 
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arob157

Go Kart Newbie
Location
USA
Well the test round for the two FPCMs brought about a fail. Upon start up, neither fuel controller is being activated or utilized. I used OBDEleven to monitor the LPFP fuel pressure and duty requested from the pump. Ignition on automatically brings up a 10% load. Upon start the stock GTI LPFP looks to request around 50-60% duty at idle. Neither FPCM was requesting any duty.

No CELs were thrown which was interesting. The system did register a code for not communicating with the FPCM for both controllers. I am currently investigating the wiring/pin out for the FPCMs for the Q7/R8 and the Touareg. I am almost wondering if the controller pinout is simply different (ground vs. power in flip-flopped; if it is, I can swap pin/wire locations in the harness).

After verifying pin outs, I can take the controllers to work and see if I can apply a load and check the controller output to see if it is sending out a signal. The other potential issue could be with the relay for the LPFP. There is a chance that the relay needs to be changed and there a a good chance that it would not be compatible with our body. I should be able to take a look at the RS3 controllers and relays to get an idea of how they are wired. I do have my doubts about that theory though because neither PAGParts nor Iroz has you change a relay. Should really just be the ECM activating the relay and then allowing voltage/current to go back to the FPCM.

I will report back with my findings as they come about. Currently this isn't a viable upgrade, but I am going to figure out why.
 

Dragk913

Ready to race!
Location
DFW, Tx
Thanks for the update! I'm very excited to see what you find out(y)(y)(y)
 

aaronc7

Drag Racing Champion
Location
Clovis, NM
@arob157 any progress? I saw a new LPFP kit that appears to be the RS3 fuel pump and an oem audi/vw controller. Just need a controller that works and figuring out the wiring/harness side of stuff and that might be a good / cheaper option as well.
 
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