E53 Electrical Gremlins
 

Morning all,


E53 3.0D - Looking for some suggestions/confirmation on the below.


Issues:


1. Both front main headlight unit indicators keep burning out on the bulbs contacts. At a glance I'm suspecting worn bulb holders not holding them tight enough causing a arc. They are fairly brittle, Thoughts?


2. My central locking has gone dead entirely. Keys got power etc tried all the reset and nothing. Suggestions on the web seem to be the GM Module. Correct or other places I should look? )I should also not I mean dead at the key, works via door lock / internal button )


All fuses are fine - None have blown and all tested ok. I have a spare GM module but aware this requires coding?

Cheers!

On #2

Carefully pry out the central locking switch from the center console and see if it is broken at the bottom. The switch housing is made of plastic and if breaks (which is common) the switch stops working and disables all central locking. If it is broken you can glue it back or replace it.

#1 Mine kept burning a right side bulbs. After replacing 2, I checked deeper. The housing internal wires have cracks. Two wires were close enough on bumps, the wires would touch an arc. Arcing burned the light bulb. Check wires for cracks and arcing.

The switch works fine unfortuantly sorry I did edit the post to note its all working via the switch and keylock just not with the key buttons (which I tested and they do work/power etc)

I did check from the holder to the connector, but I'll check further back to see if there's any splits

Do you have a bidirectional scanner? With the likes of Foxwell 510 you can activate button presses from the scanner and also confirm if a button is getting pressed.

Often when the central lock button is not working it’s because the car is seeing some sensor that precludes the doors locking. Example: you cannot central lock with driver’s door open.

While in the car, lock with key fob then see if you can unlock. Don’t take too long you’ll set off the motion alarm.

Doors are double locked from key fob so you can’t pull handle to open door to have to hold central lock button to disable the double lock.

So the test: lock with key the door handle should do nothing (dry fire).

Then hold central lock button and try the door handle again.

If you can unlock door with handle the central lock button and the hardware that it runs is functional.

When mine malfunctioned it was the upper hatch button that shortened out from rain.

The car will disable the hatch button if it’s shorted but my central lock button stopped working until I removed the damaged rubber cover from the hatch button.

(Foxwell told me the button was always pressed)


–awr–

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Hello bud thanks for the lengthy response.


Everything works - Bar pressing the buttons on the key. So I can't do any of that as noted in the original post. Same applies to trying to pair the key again it doesn't work.


Ive tested the key and power - both are working as in voltage is correct, and its reaching the buttons, and the buttons recieve power when pressed (on the key) I swapped to a new battery twice, no success.

I can lock/unlock the central locking using the key in the door


I can lock/unlock the central locking using the main button in the cabin


There was no pre-cursor to it not working - Just came out one morning and I couldn't remote cetral locking anymore.


In short its remote central locking that is borked - The central locking system itself is otherwise functioning as intended. Sorry if I wasn't super clear.

You confused me saying the central locking not working that means the button on the console doesn’t work.

What you meant to say is the remote fob no longer acts on the central locking.

This almost always is from a bad solder joint in the key. When mine (both) went bad, reflowing the solder joints on the key brought them both back to life.

Second key? The problem is if you started key paring and not successful, you may have disconnected any alternate key.

Often it’s a secondary button not working that prevents pairing since you must press two at once.

You said you replaced battery (not likely the issue). Power is not getting to the right places. If you can open the key again re-flow the solder joints on all the chips. I’d skip the ID chip for the starter since that works if you can start. Do one key at a time to make sure you didn’t break the RFID function.

When I refurbished my keys they worked ok for over a year then failed again. When they failed, symptom was they worked from less and less distance from the car so if you ever noticed needing to get closer than 100’ to unlock that’s the reality check it’s key solder joints.

My favorite fix in the 6 years i had e53 was getting a factory key. My 30-50' range went to 300' immediately. Expensive yes. Made me smile every time i used it. (I even kept the key wen insurance wrote off the car).


–awr–

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My $/£/€ 0.02: in 2023 bought a new fob/remote from BMW as the one I got with this rig was long dead. Remote lock/unlock worked fine until one day it just stopped working. I thought maybe the battery in the remote was dead already despite being new (new old stock, maybe sat on a shelf for 20 years?). Went to a battery/key shop and it passed transmit tests with a strong signal.

Did the re-pair procedure: key in ignition, turn to position 1, turn back, remove key, press the buttons in the right order. Nope. And another nope. Had to do that three times before it worked again. This happened last month too, when my fuel pump died, and again it took 3/4/5 tries at pairing before it worked. So maybe keep trying? My central locking system worked fine from the door lock and the console switch, sounds similar to your issue.

It's def worth more tries to re pair. With my iffy original keys it usually took multiple tries and usually bcai never remember if you have to start with doors locked or unlocked


–awr–

Using Tapatalk VIP on iPhone

The first post says "keys" but I am assuming you only have one? Do none of the buttons work? The pairing can be tricky because the procedure isn't totally clear on keeping the button pressed. Having a second working key is KEY when one stops working! ;)

You can test the key is transmitting at some stores where they sell key fob batteries. They might have a radio receiver that lights up when it detects a remote signal.

If you have the key open you can also test by watching the battery voltage when you press the buttons. Voltage out the switch doesn't mean the power is going where it needs to go.

When mine didn't transmit the vBat would not drop and when i fixed the solder joints (reflow), then i saw something like 0.2v drop when pressing any button.

I made a thread showing where you can use needles to poke through the key to measure voltage without disassembly. But obviously much easier if you have the key open.


–awr–

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Hey all sorry have been keeping up but was busy


So no joys with the reflows - I had already done this before but JUST incase did it again. I've ordered some new buttons on the off chance one is knackered internally.


But yea single key, I have a spare but its the hard key not the remote locking. I've tried to resync it god knows how many times and it is flat out not working at all so we'll see if the new switchs work otherwise yea I might whip into a local and see if they have a tester, I think timpsons usually have one floating around!

As long as you have the non remote key it’s safe to work on the key.

If you monitor the vBat while pressing the buttons you should see the voltage drop a significant amount the whole time the button is pressed that's exactly how i confirmed my key wasn't working.

You can measure Ω across the switch or voltage across the switch to see if the switch has failed.

In my case switch worked something downstream wasn't getting power.

Even when i reflowed the fault eventually returned and a replacement key was the true solution and even though expensive was worth every penny.


–awr–

Using Tapatalk VIP on iPhone

Morning,


Sorry I hadnt gotten back to you a lot happened!


So initially I swapped the buttons for new ones (I do SMD soldering work as a side job) no joys. So good chance I just order a new key.


Anyway the reason it all got a bit derailed is I got a Trans Prog Fail Safe pop up.


Luckily I had just landed at my unit - Code 52/53 (2nd & 3rd Gear Monitoring) No other codes....


I've got the plug to check but otherwise chances are it's the solenoid for 2nd&3rd thats gone possibly MOT tester kindly let me yoink his shiny new snap on along with a slew of historical and now deleted codes these remain. Not terrible but we'll see if the plugs choked up first.


And then to top it off... I pulled my E36 out of mothball to cover while the X is incapacitated only for the fuel pump to fail just before emissions :D


What a week...

Been there, done that.

My X's fuel pump failed as I was getting the emissions inspection, though it was running perfectly until then, and I had to get a new "reliable" Valet key the next week, after the pump was installed....

The X isn't running correctly ever since, but hopefully I can make it do so, soon.

So it seems that other X's sometimes have multiple failures on similar timescales, and it's not just the bad luck I thought it was.



Sent from my moto g power 5G - 2024 using Tapatalk

Yours failed *at* emissions!


–awr–

Using Tapatalk VIP on iPhone

Sorry, I don't understand what you're getting at?

He went to get emissions tested, and while in the bay his fuel pump died. So he said been there done that to your comment fuel pump died just before emissions.


–awr–

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Oh no the fuel pump failing was on the E36 (as mentioned in the post)


Although the X5 has it's own issue with fuel... ie the connector hose between the two so it's running off the smaller tank currenlty so no dropping below about a 1/4 tank! Pump works fine just that stupid hose between the main/res tanks is busted I just have yet to fix that one :D

Ah I did wonder what you were on about!


And yea mine died before getting to that test, we were just moving it off the brake checking machine when it conked. Highly annoying but the tester is a really good guy and messed around for 5 mins and checked the pump and confirmed it died for no extra charge.


Nice to have helpful staff, he'll be getting a xmas 6 pack!

We saw it was the other car but it’s a relatable circumstance.

My wife’s FP died one day we got home and wife wanted me to move the car a few feet to not block the walkway. Wouldn’t restart. Best timing ever to fail.

I got stranded a few times from the siphon jet failure (before learning what the hell was going on).

You said the hose was busted?

The hose has to work or the pump will move all the fuel to the left tank. Have you monitored the fuel tank levels while driving? The hose can be leaking to cause inefficient transfer left to right would give the same symptoms of jet pump leaking.


–awr–

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It's the siphon jet that's failed *presumably - Fuels being pumped to the other side of the tank which is causing the issue so I need to keep it above a certain point or it conks out. I think the secondary pump is taking up the slack.


I used the normal dash test to watch levels on the tanks and it all fits with previous posts about the siphon pump.


Other then shoddy MPG of 23.7 I'm not noticing any other fueling issues. I did have a minor leak at the HPFP but I replaced that hose with a new one from BMW so thats all solved now

The jet pump is usually repairable. There’s a design defect that makes them spray fuel out the side as the plastic part bends over time both our e53 had exactly the same failure and I’ve seen many similar on the forums.

Usually just replace the o-ring and some Teflon[emoji769] tape.

Looks like e53 siphon jet shares some dna with the e36. (Similar connector from the level sensor going down to the feet of the siphons). I’m betting same failure mode similar repair.

The first time I got stranded WA’s because wife never told me she needed to get rescued with a can of gas when the car showed ¼ tank. She just never went below ¼ after that but didn’t tell me.

So when it happened to me it was the start of my learning curve.


–awr–

Using Tapatalk VIP on iPhone

Good shout, I'll dig the pipe out when I get the car back and take a look. Hopefully its that easy! Its not a huge bug bear but it's annoying.


I miss driving on the edge of the red line :D


But with diesel prices I may swap back to E36 longer term to save on fuel!

The ¼ tank failure mode is almost always from the o-ring leaking going down to the siphon jets. It just makes the siphons weaker so they need doin some amount of fuel at the bottom of the tank to function.

If they didn’t work at all, the fuel would all stay on the left tank until it can flood over to the right. That happens at about 27L on E53, not sure when in E36.

The positive confirmation on e53 is the right tank will read a constant 1.4L of fuel steady state driving once you get below about 27L but at ≈ ¼ tank the 1.4L will start dropping to zero. You only have a few minutes/miles if that happens. When right tank reads zero there’s about 1 gallon left but your can’t drive 15-20 miles as the fuel pump will be pushing fuel to the left tank.


–awr–

Using Tapatalk VIP on iPhone

Yep thats what happens to me, get to a certain point and it dumps all the fuel over the other side.


I'll check that at the weekend, do you happen to remember what size O-Ring it was?


Something you may be able to shed some light on, I have in the boot on the left hand side looking in - Where the amp usually is, it's always wet and I have no idea where it's coming from. The light seals are brand new and fully sealed. I threw a air line over it and nothing came through.


I can't think of any other obvious places it could be coming from. Underside is fine and all the plugs are in place, I considered the roof strips which there was a small crack but that turned out to just be the paint.

Its not the washer as thats been disconnected for a long time. So I'm a little stumped

My e70 gets mystery water same location I don’t check often enough to figure out the source. I drilled a drain hole and it apparently collects slow enough no more puddle. My guess was spray from wheel but I haven’t had a chance to root that one out.

https://chatgpt.com/share/69b0351b-b...1-890b0c77c09c

GPT found an answer on the o-ring in your case. BMW doesn’t list the size but 7.5x1.5 is what GPT came up with.

That’s way way smaller than e53 so it’s less likely the fault. More likely if like e53, there’s a plastic to plastic flare fitting with no seal just plastic to plastic that’s where I put Teflon[emoji769] tape.

Find my awr-fix on the siphon jet to compare.

The connector seems similar from the BMW shop manual and if it’s held together just from one side I’m pretty confident it’s a similar problem with a similar fix.


–awr–

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E36 Is back on the road, so I have wheels to now deal with the E53!

Will attempt a fix at the weekend... then figure out how to get both cars home :D


Ill let you know if the TCC&2/3 Solenoids fix the issue