So this article is about quite standard problem you can find on lots of cars, but here its about BMW. So you started getting first random lights on the dash and later it became permanent lights on mess on the dash. Usually you get ABS, DSC, DTC, BRAKE lights on and some messages on the idrive, like drive train malfunction, etc.
Lots of mechanics diagnose it as bad abs sensors, abs pump etc, because it shows these errors on the scanner.
YES, IT WILL NOT TELL YOU THAT ABS MODULE IS BAD, IT WILL ONLY TELL YOU WHAT SIGNALS ARE LOST, THEREFORE YOU END UP REPLACING LOTS OF WHEEL SENSORS, ABS PUMPS, SWITCHES AND SO ON. THE ANSWER IS INSIDE THE ABS UNIT-TINY GOLDEN WIRES BROKE OFF FROM AGE AND VIBRATION AND THAT’S WHY YOU GET ALL THOSE ERRORS!
SO SIMPLY REPLACE ABS/DSC UNIT WITH A NEW ONE (600$+)OR GET IT REBUILD FOR 100-150$ WITH WARRANTY. NOTICE NEW CLEAN MODULE DOES NOT NEED CODING- IT IS SELF CODED, SIMPLY IT WILL WRITE VIN NUMBER AFTER YOU CONNECT IT FOR THE FIRST TIME, SO DON’T PAY ANYONE FOR “CODING” NEW UNIT. USED UNIT NEEDS TO BE REPROGRAMMED, BUT I RECOMMEND NEW UNIT OR REBUILD YOURS.
Ok, i decided to create this post because i see lots of bimmers running hot or even overheating. You would say nothing new here, right? Well believe it or not lots of mechanics or shops trying to resolve this problem with no luck and in the end as a final solution they offer head gasket repair, which won’t fix anything.
So here are the main standard problems, applies to any water cooled engine:
Radiator cap not sealing well or valve inside is not working anymore causing boiling in your cooling system due to pressure loss. Solution? replace radiator cap every 5 years even if its good.
Any coolant leak will create pressure loss and introduce air in the system. Make sure there is no leaks. Use Pressure tester.
Thermostat if bad, it stays open on these engines, and you usually get error code P0128 if heater inside burned or you get thermostat jammed error code. usually tstat lasts 70-100k easily.
Water pump impeller can slip or even fall apart or bearing might seize causing total failure. Good thing these engines head gaskets are very strong and can sustain serious overheating.
REPLACE TEMP SENSORS EVERY 70KMLS, THEY DO GO BAD AND SOMETIMES SHOW LOWER TEMPS THEN IT IS, ESPECIALLY WATER PUMP TEMP SENSOR, LOWER SENSOR IS KNOWN FOR O-RING LEAK, APPLIES TO ANY BIMMER.
Main engine fan (electric) is bad or fan clutch not working anymore, though even with a bad fan clutch and fully working cooling system you will not get overheating, unless you are in Dubai traffic:) AC fan is very effective even with a bad fan clutch. Since 2004 BMW uses only electric fan for both AC and engine, so if it goes bad, you will get overheating.
So, i was not going to create simple overheating article you can find anywhere, right? Its gotta be unique on this site! Here we go:
So what to do if there is no leaks and all hoses are new, gaskets etc, pressure tester confirmed no pressure loss, but engine still runs hot overheating transmission as well??? Did you know running hot will destroy all rubber gaskets and other rubber parts? Why? Because engine temps are not consistent like it was designed! Ok, here is something nobody cares about when trying to fix overheating issues:
NORMAL TEMPS FOR 6cyl=94-98 max
NORMAL TEMPS FOR 8cyl=103-108 max
TO CHECK RUNNING TEMPS YOU NEED TO OPEN HIDDEN MENU:
1) hold reset odometer button until you see the menu
2) go to 19 unlock menu (press button once) and enter (hold the button to enter) the sum of your last 5 vin numbers:
ex: last vin 23657, so sum=2+3+6+5+7=23
3) now go back to menu 7 and hold the button until you see running temps, if you don’t, it means you enter unlock code wrong:
here is a picture of running temps with RECALIBRATED 87C thermostat, these are actually really good temperatures for this and other V8 engines! It will keep your cooling system healthy and will prolong the life of all rubber gasket seals including valve seals. Moreover it will reduce detonation so you’ll get extra power in the city driving! Imagine lowering cooling pressure from 200 to 120??? 200 is what your tire pressure is. It is a big deal, all rubber gaskets run under serious stress and we see tons of exploded hoses, coolant tanks and other expensive leaks like:
wheep hole 2000$ if you install oem pipe
rear cover plate (Tranny needs to be removed)
valley pan (intake removal needed)
Soon we will offer these cooler temp tstats.
HEATER CONTROL VALVE! THIS VALVE DOES NOT LAST! RUBBER SEALS INSIDE BECOME BRITTLE, CLOGGING UP THE COOLANT CHANNELS GOING TO THE HEATER CORE! RESULT IS OBVIOUS=YOU CANNOT BLEED THE AIR OUT OF HEATER CORE=OVERHEATING! THIS ENGINE HAS SELF BLEEDING COOLANT SYSTEM, BUT IT WILL NOT WORK IF THIS VALVE IS CLOGGED.
HERE IS DISASSEMBLED HEATER VALVE FROM 2006 750LI with 98kmls. As you can see rubber seals are cracked and not flexible anymore, BUT if you have working auxillary water pump, you still get okay heat cabin, but system has air pocket, since you need very good flow when bleeding coolant system.
HERE IS THE MAIN PROBLEM: YOU SHOULD SEE A NICE RUBBER SEAL AROUND THE VALVE, BUT ITS ALL BROKEN AND THE WORST PART IT CLOGGED RIGHT CHANNEL COMPLETELY:
SO GOOD RECOMMENDATION IS TO REPLACE IT EVERY 5-7 YEARS AND START EVERY COOLANT SYSTEM PROBLEM FROM THIS VALVE REPLACEMENT. IF THIS VALVE IS GOOD YOU CAN DRIVE YOUR CAR EVEN WITH LEAKING COOLANT (I KNOW ITS NOT A GOOD IDEA), BUT YOU WILL NOT GET OVERHEATING ISSUES IF YOU KEEP ADDING COOLANT, BECAUSE ENGINE WILL BLEED ITSELF ALL THE TIME IF HEATER CORE HAS NO AIR POCKETS. REMEMBER COOLANT SYSTEM IS THE MOST IMPORTANT SYSTEM IN YOUR CAR!
SO UNTIL YOU SEE OIL IN THE COOLING SYSTEM, OR COOLANT IN THE OIL OR EXHAUST SMELL FROM COOLANT TANK, DO NOT BELIEVE IN THE HEAD GASKET FAILURE. WHEN HEAD GASKET IS BAD, YOU WILL KNOW IT FOR SURE:) V8, IS VERY STRONG ENGINE AND ITS NOT EASY TO DESTROY HEAD GASKET BY JUST OVERHEATING, DOESN’T APPLY TO STRAIGHT 6 THOUGH….
In this post we will be describing how to diagnose MOST bus failure in any BMW, AUDI, PORSCHE, ROLLS ROYCE, RANGE ROVER HSE, BENTLEY with MOST fiber optic bus. every car has different configuration, but principle is still the same!
So in 2000 they introduced newer multimedia bus, called MOST, IT IS VERY NICE AND FAST NETWORK, SO THERE IS ENOUGH SPEED TO CONTROL EVERY MULTIMEDIA DEVICE AND THEY ELIMINATED LOTS OF COPPER WIRES IN THE CAR. NOW SOUND IS FULLY DIGITAL AND CLEANEST (BC NO SIGNAL LOSS ON THE WIRES), SO IT IS A GOOD THING, BUT ITS MORE COMPLEX AND NOT VERY RELIABLE.
So to start you need to understand that all MOST (multimedia) modules in the car work in the closed loop, which means if any device in the loop fails-none will be working.MOST bus primary signal (optical red light signal) is generated inside of the main computer, which is your main screen CID (control display or CID in E65 car only, other BMW have main computer incorporated into head unit or CCC/CIC/NBT etc), then it travels through all MOST network devices (ask unit, amp, navi, fm tuner, phone etc. depending on how many options you have) and comes back into main head unit. Basically all units connected in the loop- one unit fails=broken network! Once you understand this principle, you can easily find broken unit or network interruption, don’t forget dealer will charge up to 500-1000$++ for such a serious job! You don’t believe me? go and try, then you will understand how priceless with post is.
Your E65 E66 or Rolls Royce phantom ( yes don’t be surprised it is the same exact car as your 760li btw) car has MOST bus failure if:
-cannot hear any sounds or music
-cannot see tracks playing on the display
-fm stations not available
-navi isn’t functioning
For other BMW like e60/e90/e70/e89/f01 and others MOST BUS FAILURE symptoms are little different because primary head unit has 4-5 modules (SVS, ask unit, MOST GATEWAY, NAVI, Radio tuner) combined and therefore everything will work except for those secondary modules: -amplifier no sound and you see mute icon on the radio or screen -TCUM or telephone module -SAT NAV receiver
Here is the MOST DEVICES order diagram , but this is only valid for basic order and only for pre 2006 cars, you might have way more devices in the network, so you have to figure it out yourself by looping eac modules and draw a diagram of the modules.
Here is a quick video showing how to find a bad unit in real time:
FOR 2006-2008 E65 E66 cars basic order will look like this:
MMIGT(screen)>>CDC>>AVT(if you have it)>>TEL>>SAT(hd RADIO)>>L7>>SVS>>NAVI>>ASK>>OOPS(GLOVE BOX MOST LOOP)>>MMIGT
FOR E60 E90 E63 E89 E90 E92 E93 and so on:
HEAD UNIT CCC/CIC/NBT>>L7AMP>>SAT>>TCU>>MULF>>HEAD UNIT
On these cars in most cases i see sat and amplifier unit failure very often, telephone module goes bad too but not that often.CCC navi units have a high rate failure, but the good thing once you replace it, you replace 5 modules at once, so its more reliable and much easier to find a faulty unit because you only have 2 or 3 modules to diagnose and all of them located in the trunk. We also offer CCC or CIC repair service
So to find out the faulty unit you either need to see a dealer (but even dealer makes mistakes), but here is an easy solution if you don’t have anything, and if you do it right it always works:
You need basically to find out where the most signal gets lost, after what device you don’t see the red light. In other words you will be checking the red light after every device in the network, and the one which is not sending the red light signal is your FAULTY MOST UNIT. OOPS is the last diagnostic connection located in the glove box and it has lollipop attached and it has to be looped there, some people think it is a spare jumper, but its not, without this jumper you will interrupt the network!
HOW TO BYPASS NON WORKING MODULE??? EASY! GET THIS P/N FROM ANY BMW DEALER 61136917541, YOU CAN GET IT ONLINE FROM ECS TUNNING ECS TUNNING FIBRE OPTIC JUMPER. YOU HAVE TO REMOVE INNER PART WITH SOME FLAT SCREWDRIVER OR A KNIFE, YOU CAN ALSO USE ZIP TIE IF YOU PLAN TO KEEP THE JUMPER BYPASSED, IRT WON’T STAY WITHOUT ZIP TIE.
most common MOST devices failure (descending from most common to less):
-SAT SIRIUS unit always goes bad, we will offer repair of this unit soon
–TCU TELEPHONE BLUETOOTH MODULE RECENTLY WE SEE TONS OF THEM FAILING!
-Logic7 amp AMP
-ask cd unit ASK
-navigation NAVI
-fm tuner
-CD itself main screen CID
-cd changer CDC
-SVS (gets flooded with hydraulic fluid from trunk opener cylinder, if you see sticky fluid on the NAVI, SVS- replace asap)
other modules. depending what you have in your car
Always check if you have red light in the glove box, disconnect that jumper and check for the light, if you found and bypassed bad unit correctly you should see the red light in the glovebox and then you can install the jumper and everything should start working. I know it sound complicated but once you understood how it works it is kind of very easy.
BUT PLEASE DO NOT BLINDLY BYPASS EVERY MODULE, LIKE LOTS OF PEOPLE DO, YOU MIGHT FIND THE PROBLEM, BUT ITS NOT EFFICIENT AND SOMETIMES YOU CANNOT DIAGNOSE IT RIGHT. ALSO MAKE SURE EVERY MODULE HAS 12v POWER. BASICALLY EVERY MODULE NEEDS FIBER OPTIC SIGNAL AND 12V POWER ATTACHED TO FUNCTION.TO WAKE UP MOST NETWORK IT IS ENOUGH TO OPEN/CLOSE THE DOOR, YOU DON’T HAVE TO START THE CAR, THE THING IS MOST GATEWAY WILL GO TO SLEEP AFTER 10 MINUTES IF NETWORK IS BROKEN AND TO WAKE IT UP YOU NEED TO OPEN/CLOSE ANY DOOR OR TURN ON THE RADIO.
THAT’S about it, IF YOU FOUND THE BAD MODULE YOU JUST SAVED 300-400$ AND TIME. REMEMBER LOTS BMW SHOPS STILL CANNOT DIAGNOSE IT RIGHT AND ALWAYS POINT TO ASK UNIT OR AMPLIFIER, “BECAUSE THERE IS NO SOUND”, WHICH IS NOT ALWAYS TRUE, I WOULD SAY IN 50% ITS NOT CORRECT EVEN FROM OFFICIAL DEALERS. WHY THEY MADE IT SO COMPLICATED AND NOT RELIABLE?? WELL THIS A FUTURE OF CARS AND TECHNOLOGY, YOU ARE THE ONE WHO ASKED TO HAVE ALL THESE TOYS IN THE CAR, SO YOU EITHER LEARN IT OR HAVE YOUR WALLET READY TO GET SKINNIER, OR BUY HONDA/TOYOTA….
The article below discusses common audio issues you may experience with your LOGIC7, standard ASK system, or both. The LOGIC7 amplifier and ASK module are used in the Rolls Royce Phantom and BMW E65, E66 models.
The audio system is available in two variants, standard 6 speaker Hi-Fi, and BMW LOGIC7 also referred to as ‘Hi-Fi Professional DSP’, ‘Top Hi-Fi’ or ‘Premium DSP’.
The standard Hi-Fi system has the following configuration:
ASK Module:
– 2 Front Mid Range Speakers and Tweeters
– 2 Rear Deck Mid Range Speakers
– 2 Subwoofer Pre-outs (fed directly to Hi-Fi Amplifier)
Hi-Fi Amplifier:
– 2 Underseat Subwoofers
Summary:
Conventional analogue amplifier, analogue audio is received from the ASK module and amplified for the two subwoofer channels.
Common Failure Modes: ASK:
– Failure of one or more front or rear deck speaker outputs, usually crackling, distorted or no audio output. This is an ASK related failure. Hi-Fi Amplifier:
– The subwoofer amplifier is very reliable and rarely suffers any failure symptoms.
The LOGIC7 system has the following configuration:
ASK Module:
– 2 Front Mid Range Speakers and Tweeters
– 2 Rear Deck Mid Range Speakers
LOGIC7 Top Hi-Fi Amplifier:
– 1 Centre Mid Range Dashboard Speaker
– 2 Rear Door Mid Range Speakers
– 2 Underseat Subwoofers
Summary:
Digital amplifier with full DSP (Digital Signal Processing) and 7 channel graphic equaliser. The audio data is received from the ASK (Audio System Controller) via a fibre optic connection, it is decoded, processed to enhance the sound and staging effects before being converted back to analogue and fed to the internal 5 channel amplifier.
Common Failure Modes: ASK:
– Failure of one or more front or rear deck speaker outputs, usually crackling, distorted or no audio output. LOGIC7:
– Sub-woofer output failure, resulting in crackling, distorted or no bass output.
– One or more of the three mid range speaker output channels can suffer crackling, distorted or no audio output.
2002-2005 Pre Facelifted ASK UNIT (CD-Player)
2006-2008 Face lifted ASK UNIT (CD-Player)
Standard problems with ASK AUDIO CONTROLLER:
– crackling, static noise from front doors and rear deck speakers. No sound at all. Therefore it will affect all service sounds like:
-PDC (parking sensors) not beeping, no NAVI guide voice, door chimes, warning sounds etc.
– in some cases ask unit controller is not responding to fibre optic signals causing MOST fibre optic bus failure. But it does not mean the problem is your ask unit or Logic 7 amp, it could be any device in the MOST BUS network, to troubleshoot and find out which module is causing failure I will cover in details in my next post, stay tuned.
THIS VIDEO SHOWS HOW TO REMOVE LOGIC 7 AMPLIFIER
How to remove ASK CD PLAYER UNIT?? EASY!
LOGIC 7 TOP HIFI AMPLIFIER 2002-2008
FIRST GENERATION BAD DESIGN L7 AMPLIFIER 2001-2006:\
NOT ALWAYS FIXABLE…. 50% SUCCESS RATE.
GOOD AMPLIFIER DESIGN AFTER 2006. 4 CLIPS:
VERY GOOD SUCCESS RATE ABOUT 90%
BMW Logic7 amplifier is a fiber optic controlled amplifier with FIBRE OPTIC CONTROLLER AND HIGH SPEED 24 BIT DSP PROCESSOR, therefore you can not install regular aftermarket amp. It produces 5 channels:
-sub woofers under front seats 8″ shallow type
-rear doors
-front center speaker in the dash
Any problems with those speakers are related to the AMP and have nothing to do with the speakers most of the times, but sometimes sub woofers get flooded and therefore can be bad, causing amplifier failure. Speakers can be easily tested: it should show about resistance=4 Ohms.
Main problem is that modules inside the amplifier overheat and die, the only way to rebuild i is to replace it, unfortunately BMW or Becker made it impossible due to non standard mini modules. we redesigned the entire system and since 2009 we did not have any returns.
Please do not even think that capacitors went bad, it never happened, but you can always check them if they are ok, before replacing it (makes sense?). But since 2009 and ~280 amps fixed none of them had bad caps.
Another problem with Logic7 amps is that when it does not sound right, those burnt modules overheat entire amplifier causing Logic board to fail, so if your amp isn’t doing well its better not to use it and fix it ASAP.
In most of the cases, APPLIES TO CARS BEFORE 2004 (AFTER 2004 THEY CHANGED SOFTWARE AND SETTINGS ARE ADJUSTABLE EVEN WITHOUT ANY AMPLIFIER CONNECTED!) if Logic7 level AND EQ SETTINGS ARE adjustable in the menu (entertainment),
it means that logic board is still okay and it is fixable, but if you don’t have any sound, or if its cutting in and out, it means that Logic7 amplifier is causing MOST bus failure, and lots of things are not working in your IDRIVE:
In my next Post i will cover how to diagnose MOST bus failure and what device causing it, because it could be any device in the MOST bus network, and to find it out you either need bmw software and cable or i will explain the way on how to diagnose it without anything.
IF YOU DECIDED YOU NEED HELP WITH REPAIR, PLEASE SEND YOUR AMPLIFIER OR ASK UNIT OR BOTH (550$X2) HERE ALONG WITH 550$ PAYPAL PAYED TO LOGIC7REPAIR@GMAIL.COM.
We have also EBAY add, so you can see real feedback.CLICK THIS LINK BELOW, MAKE A 550$ PAYMENT, PRINT A RECEIPT AND INCLUDE IT IN THE BOX WITH YOUR AMPLIFIER OR ASK UNIT AND SEND IT TO OUR ADDRESS (SEE BELOW). USUALLY IT TAKES 1-2 DAYS TO REBUILD IT AND 2-3 DAYS SHIPPING. INEXPENSIVE AND FASTEST SHIPPING IS USPS PRIORITY MEDIUM OR LARGE BOX (15$).
if your car facelifted 2006 and up, its 99% guaranteed its fixable.
before 2005 logic7 amplifiers are not always fixable, so if you have cutting in and out, or it plays only from front speakers and Logic7 level is not adjustable, most likely we cannot help, but you can still bypass it and install standard amp, though it will not sound like original one, though much cheaper.
IF YOU ARE STILL HAVING PROBLEMS DIAGNOSING YOUR AMP FAILURE PLEASE GIVE US A CALL OR TXT IF NO ANSWER, SO WE WILL CALL YOU BACK, BUT PLEASE READ THE ARTICLE FIRST, IT EXPLAINS A LOT IF NOT EVERYTHING.
NOTE: If you don’t have any sound and cannot see NAVI, FM stations, CD tracks changing or playing, it means you have at least one device failure in the MOST network and you have to find out which one (most common are: NAVI, SVS, CD changer, ASK, L7, FM tuner) is causing this problem, i will be describing it in my next post.
Disclaimer: By sending us the unit for repair you do authorize us to work on your unit. Please make sure your shipping address is correct: unit can only be shipped to the address you specified during payment, no exceptions! $100-$150 diagnostic fee will be applied if the unit needs no repairs. If you bought a replacement unit from us and your original unit was misdiagnosed as faulty we can only offer 50% refund. This is due to time spent on coding and preparing your unit plus shipping cost. Dismiss
