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Discussion Starter · #1 ·
I saw a video online of the high cluster, so I figure I do one for the low...


Seek to understand,^Value
25,199 Posts

So that others find this easily in the future, I'll add a pointer in the best links:

Doing a search for on-board computer /OBC(F3) in the bestlinks, I find:
- How to unlock your HI-OBC. Kinda sucks if you don't got this upgrade. I think ALL 540's have HI-OBC while only SOME (and i don't think it's much either) 528/525's have HI-OBC's.
- QSilver's unlocking the instrument cluster OBC and resetting oil service intervals
- How to tell if you have the high or low OBC instrument cluster
- Unlock OBC & Test or this
- How to unlock the low/high OBC on-board-computer cluster for diagnostics (1) (2)
- How can I tell if I have the High or Low OBC?
- How do I unlock the OBC (Low and High)?
- How to unlock the low/high OBC on-board-computer cluster for diagnostics (1) (2) and quickie telephone instructions for unlocking the high instrument cluster on the E39 (1)

Putting all that together with this thread, we get something like:

- How to tell whether you have the high or low on board computer cluster (1) & a nice video to unlock the low OBC (1) or the high OBC cluster for diagnostics (1) (2) and quickie telephone verbal instructions for unlocking the high instrument cluster on the E39 (1) & how to change the OBC MID IHKA KTMP temperature from degrees Celcius to Fahrenheit (1) (2) (3) (4) (5) (6) (7) (8).

Seek to understand,^Value
25,199 Posts
See also:
Found it!

This one explained it alright, as long as you have the codes and explanations as well which goes

01: Car ID, Hardware and Software Version Number, Production Date of Car
02: Instrument Cluster Test (All Digits, LED's, Lamps and Needles)
03: The actual fuel consumption (while riding) in Litre/100km or Litre per hour
04: Average fuel consumption in Litre
05: Range
06: unused
07: The actual amount of fuel in the fuel tank (in litre)
08: (My favorite! You can see that in many of my movies!) The actual speed in Km/h
09: Battery Power in Volts
10: Language (US, Spa, Ger, Jap, GB, Fra etc)
11: change am/pm
12: Average Speed
13: ETA
14: ROM Code of your Software
15: Diagnosis Information
16: unused
17: Car specific Data
18: Alarmtype
19: Lock/Unlock (Used to unlock the OBD menu from 3-21)
20: Fuel Consumption Correction Factor (Don't mess with that!)
21: Reset of Boardcomputer (ATTENTION:Will clear all stored Data!(Time,Date,Radio...)

Basically you hold the "reset km" pin till the menu pops, go to menu 19, click on it while it says "off", then wait for it to go back and Select menu number 9 which displays volt. But like mentioned, can only be used when engine not running.

Seek to understand,^Value
25,199 Posts
There are so many good graphics from QSilver7 that I don't know where to put them, so, I'll add the ones from this thread today so that others can more easily find them:
> E39 (1997 - 2003) > 1997 low cluster
The instructions for resetting the (low) OBC is in the very last paragraph...after the text that is underlined in blue:

Otto Zwei-Punkt-Null
3,522 Posts
Yeah I do the temp thing all the time, with as many times as Q has posted the steps to follow for low cluster I figure it didn't need a video, but now there is a video and future generations of E39 owners will rejoice in the ease and convience!! I plan on teaching all these things to the next owner after me,. Along with handing him my ever expanding 3 ring binder of recipts, car parts numbers, order confirmations, explainations of work I've done and why.. So he'll know what parts are in the car, what brand the part is, and at what milage it was installed. I'm maybe too thorough.

Seek to understand,^Value
25,199 Posts
There is good information in this thread today for unlocking the low OBC ...
- Will unlocking the OBC show the battery voltage
You should have mentioned you needed the low cluster unlock procedure in the orig post. :)

BTW...TEST 9 shows voltage. If ignition is in position 1 or shows battery voltage...I prefer position 1 since only a few modules are running thus a lower draw on the battery. In position 2..all control modules are running thus the voltage reading drops faster. With the engine running you get the alternator/charging system's voltage.

I'm on my phone so it difficult to post this info...but just Google "how to unlock the low cluster qsilver7" to find a past thread that has this info. I've posted this info enough over the last decade that you should get a previous post on one of the several bmw forums I'm affiliated with. :)

EDIT: yep a simple Google search turned up this

Low cluster unlock procedure + description of tests:
High cluster unlock procedure + description of tests:
Test 9 will not give you battery voltage.
Current flow from the alternator to the battery, then to the glovebox fuseblock and finally to the instrument cluster causes voltage drops along each segment.
Depending on the amps being drawn (i.e. components turned on) you will see ~0.2 to 0.3 V drop from alternator to battery and a further ~0.2 to 0.3 V drop from battery to cluster. These V drops are not a fault - every electrical circuit has voltage drop unless the wiring is a superconductor.

See this post for an explanation and further comments.
If the engine is not running...are you still getting current flow from the alternator?

I do recognize that TEST 9 with ignition in position 1 will not read the same as measuring from the battery posts...again due to control modules running thus creating a draw...but couldn't that still give an indication of the battery's voltage when a meter isn't available? And again...if the engine isn't running...can the alternator send current to the battery?

Also, the BMW description of TEST 9 for the low & high cluster says "battery voltage"...not alternator/charging system :

There can't/won't be current flowing from the alternator, but there will be current flow from the battery to the fuses in the glovebox & trunk, then onward to any active modules. So there will be 2 voltage drops to consider:
1) voltage drop due to resistance in the wiring from battery to glovebox, which will be proportional to the current. I don't know what that is in key position 1 (accessory) In position 2 (run) I suspect it is at least 25 amps since many vehicle systems are active.
2) since the battery is providing current, terminal voltage will be less than the open circuit voltages found in the tables of state of charge vs temperature. Again proportional to current draw.

I've just now gone out, unlocked the car & called up test 9 at key position 2. The car has been sitting overnight at ~15F. Test 9 indicated 11.3 V, so supposedly the battery is dead as a doornail. Yet it cranked normally and started immediately. My battery is 1 year old & I've no reason to suspect any problems. It's started the car over the last few weeks with temps as low as -10F. This summer I checked sleep current & found ~20 mA. I've no reason to suspect rogue modules, such as the FSU, coming awake spontaneously and draining the battery.

So I think cluster test 9 is not useful for checking battery state of charge, in fact it seems to be misleading. It is though useful for checking that the alternator is working properly. For instance if it isn't able to maintain mid-13 volts or higher with all electrical accessories on: cabin blower high, rear window defogger, headlight high beams, seat heaters, w/s wipers, auxillary fan, etc.

As for the cluster test descriptions, it wouldn't be the first time that the German to English translation got mangled. Or that descriptions were less than a model of clarity - witness some the DTC Pxxx descriptions.

Hope this helps.
Thanks for your input & info...but I wouldn't call 11.3 volts dead as a door nail. :) At 11.89 volts the battery is considered at 0% state of charge...yet there is reserve capacity, cranking amps, and cold cranking amps that still provide current/power for starting the vehicle for a specific time period and load conditions.

Deader than a door nail...I would call that when there is no power provided at all which we see no interior lighting, no radio, no exterior lights, and silent starter...just to name a few total no power conditions.

And again, at ignition position 2..ALL control modules are running versus position 1 where only a few are running...thus the electrical draw/drop would be greater. Test 9 may not be pe r fect...but can still be useful in a no start situation...if you see anything below 10.8 to get the jumper cables out or your battery charger...because 99% of the time the starter isn't turning the engine over is because the battery is too low. At or around 11.2 volts-up...even in very cold or hot confitions...1st crank without heavy electrical drain or draw will still get the vehicle started.

Test 9 with ignition in position 1 or 2 can also be used when jumping or charging the battery to tell when it's reached voltage high enough to attempt a start..again I would recommend when voltage reaches close to 12 volts.

Obviously a meter is the best tool to have/use...but if you don't have one handy...test 9 with a bit of common electrical knowledge can be utilized for some quick on the spot diagnosis (MacGyver style). :)

And last...I totally agree with the "translation" issues...but also recognize that the beginning instructions specifically state KLR which specifically indicates ignition position 1. KL 15 would indicate ignition position 2 and KL 30 would be engine running.
One by one, EVERY stumbling block you are running into, I've been adding the solution to the battery & alternator test thread so that the next person has all the answers.

As for the cluster, we've pointed you to the unlock procedure, but, from memory, here's the simplest I can make it:

  1. Hold down the right button (about 10 seconds) until test 01 shows
  2. Press the left button to get the results of test 1 (your VIN)
  3. Add up the last five VIN digits, e.g., GZ12345 = 1+2+3+4+5=15
  4. Press the right button to go to any LOCK=ON display
    • Note: This is different than the instructions which say to go to test #19, IIRC
  5. Press the left button until it displays that number (15 in this example)
  6. With that number displayed (e.g., 15), now press the right button (this should unlock the display)
  7. To see alternator output, press the right button to get to test #09
  8. Press the left button to view the results (e.g., 13.7 volts at idle)
Note: This is from memory ... so anyone who sees a discrepancy, please correct so we can add these as 'telephone' instructions to people stuck on the road.

The only two tests I find useful on the display are test #7 (KTMP) and #9 (UB).

See also:
- How to tell whether you have the high or low on board computer cluster (1) & a video showing how to unlock the low OBC (1) or the high OBC cluster for diagnostics (1) (2) and quickie telephone verbal instructions for unlocking the high instrument cluster on the E39 (1) & how to change the OBC MID IHKA KTMP temperature from degrees Celcius to Fahrenheit (1) (2) (3) (4) (5) (6) (7) (8) & how to retrofit an E39 from the low obc to the high obc (pdf)


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