[djx]

Hi guys, I'm new here but having owned an E39 for some years i'm not new to bmw's.

I have just got an issue with my diesel E93 cabrio (325d). it cut out on me just as was going out. The car had started fine and ran for around 5 mins or so before i decided to head out. It then just cut out and refuse to start, but cranked over fine.

The AA diagnosed a faulty camshaft sensor which i have replaced but it still wouldn't start.
After a bit of digging around i found that a 20amp fuse in the enginge bay ebox had blown so i replaced this and it fired straight back up.
After about 20 mins or so the car died again and this same fuse has gone again. There is a blue relay and a black relay next to this fuse block and the black relay is hot. I have taken it out of it's plastic casing and the metal parts are too hot to touch. I'm guessing this is why the fuse is blowing but can't find any info on what the fuse is for. can anyone help please.

The photo attached shows the fuse block and the blue relay, the black housing has the black relay removed.

[ckev70]

any chance of getting getting codes off the ODBII port

https://www.newtis.info/tisv2/a/en/e...trical-system/

or using https://www.realoem.com/ may help narrow down the parts in the the DME

[gbalthrop]

Originally Posted by djx

...E93 cabrio (325d). it cut out on me just as was going out. The car had started fine and ran for around 5 mins or so before i decided to head out. It then just cut out and refuse to start, but cranked over fine.

The AA diagnosed a faulty camshaft sensor which i have replaced but it still wouldn't start.
After a bit of digging around i found that a 20amp fuse in the enginge bay ebox had blown so i replaced this and it fired straight back up.
After about 20 mins or so the car died again and this same fuse has gone again. There is a blue relay and a black relay next to this fuse block and the black relay is hot. I have taken it out of it's plastic casing and the metal parts are too hot to touch. I'm guessing this is why the fuse is blowing but can't find any info on what the fuse is for. can anyone help please.

The photo attached shows the fuse block and the blue relay, the black housing has the black relay removed.

Hi DJ (X = Incognito?), Welcome to the Forum!

I don't know anything about your 325d, but TIS Online Service Manual can help you if you go to this site and enter the last 7 characters of your VIN. Bookmark/Save the resulting page (for your specific vehicle) as you will certainly want to revisit that site. It has great circuit diagrams, and I have linked a few farther below, based upon my SWAGS of which circuits may apply. Circuits vary by Engine, Build Month/Year, as well as model.
https://www.newtis.info/tisv2/a/en/

First thing to do is identify the fuse circuit that the "Unidentified" 20A fuse relates to. It would appear that whatever circuit is served by the fuse you replaced has component or wiring failure that is causing too much current draw, blowing the fuse. The fact that it took ~ 20 minutes for the 2nd fuse to blow suggests a component "heat-related" issue (electrical component internal heat buildup during use) rather than a wiring short (which would blow the fuse immediately).

After identifying that circuit, you can test for resistance using the Ohms function of a cheap multimeter, and disconnect components to see if resistance goes UP (eliminating a relative short-circuit). Easier/cheaper to test that way rather than blow a bunch of 20A fuses. Of course there may be a wiring or connector fault that is causing a "near-short", so some creative testing is called for rather than throwing parts (you already have TWO good Camshaft Sensors and 2 blown fuses ;-).

SWAG #1: is that you replaced fuse "F01," which is a 20A fuse, located in the E-box under the hood at the location shown in the attached "Installation Location," and providing power to the Camshaft Sensor:
https://www.newtis.info/tisv2/a/en/e...d-cab/IRJqpuu6

That is simply a guess on my part, based upon the fact that you had a code for no Camshaft Sensor signal (I presume from your description), AND that there was a blown 20A fuse in the E-box which upon replacement allowed engine start.

Also, IF there is no Camshaft Sensor signal (NOT sure exactly what your code was), the engine cranks but does NOT fire, as that signal is necessary to correctly time the pulse of the injectors, so you had NO injector function. I'm NOT familiar with the Diesel engine and therefore know nothing about the other 3 components on that fuse F01 circuit, but here is the circuit from TIS:
https://www.newtis.info/tisv2/a/en/e...1-fuse/hHTSMIK

SWAG #2: the "DDE Main Relay" or "K2003a" is the relay that provides power to F01, which in turn provides power to the Camshaft Sensor and the other 3 components shown in the F01 circuit diagram. IF THAT is the relay which got hot (see Installation Locaation), that is one more clue that you NOW know with certainty which circuit to test for excessively LOW resistance (short).

That DDE Main Relay provides Battery (unswitched) power to F01, F02, F03 & F04 per this circuit, but if Camshaft Sensor was only fault read, F01 seems likely:
https://www.newtis.info/tisv2/a/en/e...supply/h6DyiB0

If my guesses about the fuse & relay in question are incorrect, you can get more information on any component in the diagram (Installation Location, Connector View, wiring diagram) by simply clicking on the BLUE component ID#.

You want to test for resistance with power DISCONNECTED of course. If you had a clamp meter that is capable of reading DC Amperes (Current Flow) just by clamping a wire, you could always test that way with Ignition ON, but I would only do that as final confirmation, as you will run out of 20A fuses.

Please let us know what you find,
George

[djx]

thanks for such a detailed reply. i'll have a read through and let you guys know.

[djx]

ok guys just an update on this.

I have changed out the overheating relay for a new one. replaced the fuse and the car starts ok.

It will run like this forever UNTIL i put the car into reverse (It's a manual btw) then the car dies with the blown fuse again.
The reverse lights are working ok

UPDATE 2:- The fuse blows when i put it in reverse even if the key isn't in (ignition off)
Is it worth getting a new reverse light switch or the fact that the lights are coming should mean it's ok

[gbalthrop]

Originally Posted by djx

...I have changed out the overheating relay for a new one. replaced the fuse and the car starts ok. It will run like this forever UNTIL i put the car into reverse (It's a manual btw) then the car dies with the blown fuse again. The reverse lights are working ok UPDATE 2:- The fuse blows when i put it in reverse even if the key isn't in (ignition off)...

As requested in my first post in this thread, in order to help you, we need to know WHICH relay was "overheating" and WHICH fuse is blowing. I thought from your original post in this thread that the blown fuse was in the E-box??? Now you are describing a fuse blowing whenever you put the M/T car in reverse, even without the remote key in the slot and ignition OFF???

Please identify the relay by number in the TIS diagram I linked initially, with the help of the "Installation Location" (ALSO linked ;-) AND please ALSO identify the Fuse or Fuses which originally blew and/or are NOW blowing when you put it in reverse with ignition off.

Here is the Reverse Light Switch TIS circuit diagram for the 2008 325d E93:
https://www.newtis.info/tisv2/a/en/e...lights/apJiaOH

Notice Connector X6021 (on the Diesel, X6011 on the Petrol model) in the wire between the switch (S8511) and the FRM (Footwell Module). Those two connectors are located in the E-box as shown in this "Installation Location":
https://www.newtis.info/tisv2/a/en/e...d-cab/IRVeOggQ

My first SWAG would be that someone has recently been in the E-box and has mis-connected the Gray/Violet wire from the switch (which is a GROUND when Reverse is selected) to a wire related to WHATEVER fuse (FO1???) is blowing when reverse is selected (which immediately shorts that mystery fuse to ground via the Reversing Light Switch.

We can offer more specific suggestions of what to test next, but there are getting to be WAAAY too many suppositions here without specific identification of (1) the hot relay and (2) the mystery fuse that blows when reverse selected. Now add as #(3) a confirmation of what connector the Gray Violet wire from the Reversing Light Switch is connected to. Photos might help if you are NOT sure from the TIS diagrams.

MORE QUESTIONS:

Are your Backup Lights ON all the time? ONLY when key in slot? Only when ignition ON? If you have NO fuse in the F01/ Mystery fuse socket (so you don't have to worry about it blowing) do the backup lights come on ONLY when reverse is selected (key on or off)? If the latter, then something related to the blowing fuse is mis-connected to the ground connector X6021, which ONLY becomes ground when reverse is selected.

There IS an answer to this, and it's silly-simple once the wiring is properly traced. Let's start with properly identifying the blowing fuse.

George

[djx]

hi, so many thanks again.

The relay that is getting hot is K9137 cut off relay, electric fan.
The fuse is the end one, F01, 20 amp. This is the fuse that is blowing when i pop the car into reverse (even without the key inserted).

The reverse light appear to be working as normal and are not on all the time. They come on as normal when the car is put into reverse.

[djx]

Just another update guys, still no joy although maybe a bit further along.

So.. When i open the car door i can hear an electrical buzzing/ whirring noise from somewhere. It lasts about 10 seconds or so then stops.

If i put it into reverse whilst this buzzing is happening then it blows the fuse.
If however i wait until it has stopped, or i don't open the door, then i can happily put it into reverse and it will not blow the fuse.

I have changed the reverse light switch today but no difference. I have also traced the wiring from the reverse light switch back up into the engine bay and there are no breaks/ chafed wire, etc.
I have disconnected everything that is on the same section of harness (exhaust sensors, a/c pressure, etc) but this didn't make any difference.

I have probed the reverse switch connector with a multimeter and the brown wire has good ground (which is correct) but the other wire is also put up a ground (around 450ohms) is this correct?

Thanks for your help so far, yet again i'm running out of ideas

[zackkcaz25]

Originally Posted by djx

Just another update guys, still no joy although maybe a bit further along.

So.. When i open the car door i can hear an electrical buzzing/ whirring noise from somewhere. It lasts about 10 seconds or so then stops.

If i put it into reverse whilst this buzzing is happening then it blows the fuse.
If however i wait until it has stopped, or i don't open the door, then i can happily put it into reverse and it will not blow the fuse.

I have changed the reverse light switch today but no difference. I have also traced the wiring from the reverse light switch back up into the engine bay and there are no breaks/ chafed wire, etc.
I have disconnected everything that is on the same section of harness (exhaust sensors, a/c pressure, etc) but this didn't make any difference.

I have probed the reverse switch connector with a multimeter and the brown wire has good ground (which is correct) but the other wire is also put up a ground (around 450ohms) is this correct?

Thanks for your help so far, yet again i'm running out of ideas

is the buzzing coming from underneath like fuel prep or interior?

[djx]

Originally Posted by zackkcaz25

is the buzzing coming from underneath like fuel prep or interior?

Hard to tell really, i think it's interior but can't be sure

[gbalthrop]

Originally Posted by djx

... When i open the car door i can hear an electrical buzzing/ whirring noise from somewhere. It lasts about 10 seconds or so then stops. If i put it into reverse whilst this buzzing is happening then it blows the fuse. If however i wait until it has stopped, or i don't open the door, then i can happily put it into reverse and it will not blow the fuse. [Since USUALLY when you put it in reverse you want to move the vehicle Rearward with ignition on, and engine running, (as opposed to keeping the car from rolling when parked), we really need to get it to NOT blow F01 when ignition ON and you put it in Reverse (M/T)] I have changed the reverse light switch today but no difference. I have also traced the wiring from the reverse light switch back up into the engine bay and there are no breaks/ chafed wire, etc.
I have disconnected everything that is on the same section of harness (exhaust sensors, a/c pressure, etc) but this didn't make any difference. I have probed the reverse switch connector with a multimeter and the brown wire has good ground (which is correct) but the other wire is also put up a ground (around 450ohms) is this correct?

I thought you had identified the problem when you ascertained that selecting Reverse caused F01 to blow, but perhaps my observations related to the two wiring diagrams (A) Reversing Light Switch circuit, and (B) F01 circuit were not clear so let's try again.

Here is the Reversing Lights circuit from TIS:
https://www.newtis.info/tisv2/a/en/e...lights/apJiaOH

The Switch is S8511 shown in the Lower Left Center of the schematic, the 2nd box from the left, for M/T and Diesel. Note that there are TWO wires attached to the switch's connector, X8511: (a) a Brown/Orange wire which is connected to chassis ground at one end, and to Pin #2 of X8511 at the other end. This Brown/Orange wire should have near-zero resistance in relation to ground at Pin #2 of X8511; (b) a wire which MAY or may not be Gray/Violet, which is supposed to go to Pin #8 of Connector X6021 in the E-box, and from there go to the FRM (Footwell Module). We can't tell from the schematic what color the wire is at pin #1 of X8511, and it may NOT be Gray/ Violet, BUT the wire to which it connects at Pin #8 of Connector X6021 IS Gray/ Violet according to the TIS diagram.

What happens when you put the M/T in Reverse gear: the Reversing Light Switch (S8511) closes the circuit or connects the chassis ground at pin #2 of X8511 to the wire that is supposed to go to Pin #8 of X6021 in the E-box. When R is selected with M/T shift lever, that wire, whatever it is connected to in the E-box, becomes a ground, and the grounding of that wire (by closing the Reversing Light Switch) SHORTS F01 (IF ignition on/F01 powered by DDE Main Relay -- see below), just as if you had touched the Red/White wire coming from F01 in the following diagram to GROUND. The closing of the Reversing Lights Switch contacts is SUPPOSED to provide a ground to the FRM to activate the lights, which it apparently DOES; it is NOT supposed to ground F01, which it apparently ALSO does :
https://www.newtis.info/tisv2/a/en/e...1-fuse/hHTSMIK

For Fuse F01 to BLOW when Reverse is selected, that fuse F01 needs to be Powered (DDE Main Relay, K2003a) closed or activated by the DME, which it is during fuel pump operation for several seconds upon unlocking, or upon "Ignition On" (different events, either of which activates DDE Relay). See this circuit for DDE power supply:
https://www.newtis.info/tisv2/a/en/e...supply/h6DyiB0

So you or someone who is conversant in reading circuit diagrams and testing wiring, need to determine WHERE the wire from Pin #2 of X8511 is connected in the E-box, and HOW that is improperly connected to the Red/ White wires from F01, causing F01 to BLOW whenever Reverse is selected, and that "Gray/Violet" wire becomes ground.

Since you already have access to the Reversing Light Switch connector (X8511) at the transmission, test that theory by simply disconnecting the connector from the switch (so that the switch will NOT connect the two wires in the connector when Reverse is selected. Merrily Shift from reverse to N with engine running, and F01 should NOT blow, and the engine should NOT die. ONLY downside, you will NOT have Reversing lights since NO ground supplied to FRM.

So if THAT goes according to my prediction, we have to electrically trace the wire going from Pin #2 of X8511, and see WHAT is electrically connected to it in the E-box, and HOW the Red/White wires coming from F01 are connected to that wire (They should NOT be).

If that is NOT clear, OR the suggested test (X8511 disconnected from Switch) does NOT work as predicted, please let me know. If you are not sure how to trace the wire from Pin #2 of X8511, and would like further suggestions, please post back. Assuming you have the N57 engine, here is the Installation Location for X2051, which is the connector to which the F01 Fuse 12V+ output (Red/White wire) attaches, and is being shorted to GROUND when R is selected:
https://www.newtis.info/tisv2/a/en/e...d-cab/IRJBQX0t

Finally, here once again is the "Installation Location" for X6021 to which the Reversing Light Switch should be connected at Pin #8, and ALSO the "Connector View" for X6021 (assuming N57 engine):
https://www.newtis.info/tisv2/a/en/e...d-cab/IRVeOggQ
https://www.newtis.info/tisv2/a/en/e...d-cab/CjsCQsMc

I'm NOT personally familiar with YOUR E-box and the various connectors shown in the TIS circuit diagrams, but TIS is generally reliable, and you obiously have the Red/White wire getting shorted to ground by the Reversing Light Switch. Figuring out HOW those two are getting together due to improper wiring or a failed connector has to be done by proper testing on your end.

George

[djx]

It pains me to bring this thread up again but i'm still having some kind of trouble.

Firstly, Gbalthrop (George) you have been a MASSIVE help so far and i really appreciate it.

From my initial trouble i have now stopped the fuse blowing (F01 in the E-box) but when i turn on the ignition the reverse lights come on and parking sensors start staright away.

The wires that goes from the E-Box that carry the wire for the reverse light switch wire pass through a rubber sleeve, when i wiggled this sleeve it seemed to make a difference as to whether i had voltage on the wire where i shouldn't have done. i have separated the wires here and recovered what looked like breaks in the insulation. After puting it back together i started the car and put it into reverse and all seemed ok. I thought i had won at this point.

So now i put the key in and press the start/stop button (not starting the car) and my reverse light are on and i can hear the parking sensor beeping (as i'm close to a wall).
My initial thoughts were that the reverse light switch may be at fault and as i had messed with this i have swapped it out for a new one. The reverse lights are coming on even though the connector (X8511) is unplugged from the switch.

I do have a good ground from the brown wire. On the the grey/violet wire i have 12volts for approx 5 mins then something must shut off and the 12v dissapears. This comes back again for 5 mins or so once the ignition is switched on again.

Currently i'm slowly stripping back the car trying to trace wiring but no such luck.

Am i missing something obvious here. My initial though was that the my original issues (car blowing fuse and cutting out when reverse selected) and this new issue must be related but i'm not sure. If i unplug the connectors from the rear light units the parking sensors still come on (obviously not the lights).

I'm stuck , HELP!!!

[gbalthrop]

Originally Posted by djx

...
[1] I have now stopped the fuse blowing (F01 in the E-box) [THAT is a good start -- WHAT did you change to accomplish that?]
[2] but when i turn on the ignition the reverse lights come on and parking sensors start staright away.

[3] The wires that goes from the E-Box that carry the wire for the reverse light switch wire pass through a rubber sleeve, when i wiggled this sleeve it seemed to make a difference as to whether i had voltage on the wire where i shouldn't have done. [The wire from Pin #8 of X6021, should have NO voltage in relation to ground, NOR should it have continuity to ground until Reverse is selected, at which point it IS ground (IF the connector is attached to Reversing Light Switch), or virtually NO resistance in relation to ground. If wiggling that wire causes it to have voltage in relation to ground, then there must be bad insulation in BOTH a 12V+ wire and the "ground" wire coming from the Reversing Light Switch (S8511). I would try to identify any other wires in that "sleeve", by color, and by Pin# & Connector to which they connect in the E-box (we can then identify them in the proper electrical circuit) and properly insulate any cracked wiring insulation by wrapping with electrical tape.]

[4] I have separated the wires here and recovered what looked like breaks in the insulation. After putting it back together i started the car and put it into reverse and all seemed ok. I thought i had won at this point.

[5] So now i put the key in and press the start/stop button (not starting the car) and my reverse light are on and i can hear the parking sensor beeping (as i'm close to a wall). My initial thoughts were that the reverse light switch may be at fault and as i had messed with this i have swapped it out for a new one. The reverse lights are coming on even though the connector (X8511) is unplugged from the switch. [What that means is that the Grey/Violet wire that goes to the FRM from Pin #8 of Connector X6021 is somehow grounded (independent of the ground wire from the switch) and that ground signal to Pin #19 of Connector X14261 at the FRM causes the FRM to activate the Reversing Lights and the Parking Sensor (as it should). The problem is WHATEVER is causing that Grey/Violet wire to be "grounded".]

[6] I do have a good ground from the brown wire. On the the grey/violet wire i have 12volts for approx 5 mins then something must shut off and the 12v dissapears. This comes back again for 5 mins or so once the ignition is switched on again.

Please describe by Pin# & Connector (Per TIS wiring diagram below) EXACTLY WHERE you are measuring 12 Volts on the Grey/Violet wire. ALSO, please described EXACTLY what you are contacting with each probe of your meter to read 12 Volts, and/or attach a photo or two identifying exactly where you are measuring that voltage. It appears that you have at least prevented F01 from shorting out, BUT as a part of the SAME issue, you have a "False Ground" or "Short to Ground" in the Grey/Violet wire causing the FRM to light the Reversing Lights (and activate the Parking Sensor) whenever Ignition is on, or more correctly, until the FRM goes to sleep after Ignition OFF (and FRM is no longer active).

Perhaps the best test NOW would be to disconnect the Grey/Violet wire from Pin #8 of Connector X6021, and then measure voltage BOTH on the disconnected wire, AND at the connector to which the wire WAS connected.

If that doesn't change anything, then I would disconnect the Grey/Violet wire from the FRM connector, X14261, and if NOW the Reversing Lights go out, and the Parking Sensor doesn't sound, you have a short to ground in the Grey/Violet wire between the E-box and the FRM.

Please let us know what you find,
George

https://www.newtis.info/tisv2/a/en/e...lights/apJiaOH

[djx]

sorry for the delay, i haven't managed to get on the car until today.

I have checked across the pin you suggested and there is no short to ground using the multimeter on the pins. There is a good connection between pin 8 (connector X6021) in the e-box and pin 19 (connector X14261) which is connected to the FRM.
This grey/violet wire does not ground at all.

Would i be right in thinking that the FRM2 is at fault. Now that i think about it i am getting some rather random warnings pop up on the instrument cluster when i know there is no issue with these.
The warnings i had were...
Tyre pressure
bulb failure
washer fluid low
ABS
The car on the jack warning.

[djx]

Final update on this..

Car appears to be now fixed and i could not have done this without help from here.

Turns out it was the FRM2 module. I got another from ebay, coded it myself using information from here and solved the problem.

Thanks so much everyone who helped

[djx]

well, not wanting to bring an old thread up but here i am again with the exact same problem.

The same fuse blows after putting the car into reverse.

Given the previous info i was armed to go straight for a second hand FRM2 again but definetly no luck this time, the replacement frm2 has been vin changed and coded in but still blows the same fuse and throws up loads of errors
such as start assist inactive, both rear turn signal failure, tyre pressure failure, brake failure.

Could this ebay frm2 be faulty, and should i try another before starting to rip the car apart again.

[djx]

Still no joy, got hold of another frm2 and still the same issue

Are there any electrical wizards on here who can point me in the right direction.

[djx]

Ok, I've spent the day tracing the wiring from the fuse that keeps blowing back to the components that it powers.

From F01 (in the ebox fuse block) the red/white wire goes to a junction (located next to it) that splices off into 5 red/white wires. These go off to the sensor on the turbo, the camshaft sensor, hall effect sensor(not sure what it's called) and the throttle body sensor (haven't traced the 5th wire yet)

The throttle body wire goes to a permanent ground when connected to the throttle body (i'm assuming this is wrong). when disconnected from the throttle body then the wire seems ok.
I've taken the cap off the throttle body and the pcb is swimming in oil, the ground pin (brown wire) and the red/white wire pin (next to it) are connected electrically insidethe unit, again, i'm assuming this is incorrect and would explain my fuse blowing?

[gbalthrop]

Originally Posted by djx

Ok, I've spent the day tracing the wiring from the fuse that keeps blowing [F01 in E-box I presume?] back to the components that it powers.
From F01 (in the ebox fuse block) the red/white wire goes to a junction (located next to it) that splices off into 5 red/white wires. These go off to the sensor on the turbo, the camshaft sensor, hall effect sensor(not sure what it's called) and the throttle body sensor (haven't traced the 5th wire yet)

The throttle body wire goes to a permanent ground when connected to the throttle body (i'm assuming this is wrong). when disconnected from the throttle body then the wire seems ok.
I've taken the cap off the throttle body and the pcb is swimming in oil, the ground pin (brown wire) and the red/white wire pin (next to it) are connected electrically insidethe unit, again, i'm assuming this is incorrect and would explain my fuse blowing?

Last time we "played along at home with your dilemma", TIS was operative (BEFORE 10/8/2020) -- NOT so today. Your "header" says "2008 E93 325d", which you state is an E93 (MT). I'm using ISTA now to get wiring diagrams. ISTA shows NO F01 circuit for 2008 325d. BMW E9x models sold in US did NOT have F01-F05 in E-box AFTER 3/1/2007 build date. I realize you are in UK.

Please provide Last-7 Characters of VIN so we can get correct wiring diagram (SSP) to properly diagnose the ENTIRE circuit. Also please indicate build Month/Year and Engine (M57/N47).

Thanks,
George

[djx]

Hi George, It was you that helped massivly last time.

The last 7 digits are E114122 (prod date 09/2008)

[gbalthrop]

Entering your VIN in ISTA, the Identified Vehicle is: E93, 325d, M57, MT, ECE, RL/RHD, built September, 2008.
There is NO single fuse F01 circuit diagram found.

Doing "Text Search" for "F01", Filtering for SSP (Wiring Diagram) documents ONLY provides FIVE different SSP
Wiring Diagrams which are attached below. The Components to which power is supplied by F01, per those diagrams:
1) Boost Pressure Adjuster
2) Throttle Valve
3) Hall-effect Sensor, Cam 1
4) Rail Pressure Control Valve
5) Volume Control Valve

Also attached is ISTA ScreenPrint of Reversing Light wiring diagram. Two+ years later, I don't recall exactly HOW
I "thought" the X6021/8 Connector and "R" switch was related to F01 blowing when R selected, & TIS links don't work.
If R selection is believed associated with F01 blowing, I would try disconnecting the wire that comes from
R-light Switch at X6021/8, and see if F01 no longer blows. If so, THEN the issue becomes WHAT is wired incorrectly
causing Ground provided by R-light Switch to short F01. I don't immediately see any way an internal fault in FRM
would cause F01 to blow, as that is NOT related to F01. Does your vehicle have PDC or Backup-Camera?
Has any aftermarket device triggered by Reversing Light Switch been added? Have you traced EACH of the wires
spliced to F01? Is there SOMETHING that ADDED to the components powered by F01 per attachments?

I know NOTHING about the M57 engine or DDE's in general. I'm simply providing ISTA document ScreenPrints.
George

[djx]

Hi George,

The car does have PDC (factory not aftermarket) .

I'm suspecting there may be a fault withthe electric throttle valve and i'm unsure if you can confirm this or not (or even add to my suspicions)

Each one of those iterms (Hall sensor, boost pressure, throttle sensor, etc) all run from the same fuse (F01 - 20amp) located in the ebox. From that fuse they join at a splice, i have dismantled this splice currently so i have 5 seperate wires and i have traced and labelled each one back to their respective harness connectors. My only issue one is the electric throttle valve. With this one disconnected from the thottle valve then i have no issue, but as soon as i make the connection to the throttle valve then the red/white wire goes to ground (i can only imagine that this should NOT be happening).

I have taken the throttle valve off the car and opened up the casing only to find it is FULL (and i mean full) of oil. Could this have caused an internal shorting or damaged some electrics on the board