ScD 0 Report post Posted February 12, 2005 Just bought a mint '88 E34 535i and I'm, stoked with the car but for one small problem: the trip computer looks to be broken. The clock must be working, because I get the hour beeps and time flash in the instrument cluster, but pressing the button on the indicator stalk does nothing. With the lights on, the computer keys are backlit, but the LCD is dim. I've checked all the fuses in the engine bay, but can't find anything wrong. Anyone got any ideas? Quote Share this post Link to post Share on other sites
Gus 5 Report post Posted February 13, 2005 the backlight tends to go on these things.....www.bmwe30.net has a how to for the e30, i imagine the e34 is similar story, just replace the stock for an LED, much cheaper Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted February 13, 2005 my trip computer works fine but at one time i had the all the panels out round the drivers side of the dash.On the rhs down by the steerng column is a "speaker grill",and behind that is the chime.when i had that unplugged my dash display didnt work,there are two plugs one will kill the chime but one obviuosly mucks up the circuit.The other thing is the PO may have had the display programmed to show nothing.You can choose which obc functions you want displayed...... Quote Share this post Link to post Share on other sites
ScD 0 Report post Posted February 13, 2005 It may be the backlight behind the LED display, from what I can gather, there are three bulbs behind the OBC, so that would explain why the keys are still backlit. Ill check it out when I got some free time in the evening. If it is poked, can I have yours kiwi535 Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted February 14, 2005 yes you can have it for 15000 and the rest of the car for free...... Quote Share this post Link to post Share on other sites
ScD 0 Report post Posted February 20, 2005 You were right kiwi535, I pulled the OBC out and put new bulbs in ($3 each from an auto electrician round the corner from my apartment) and after a brief PPPP error the first time I started the car, it lights up fine. A couple of issues tho: The temperature always displayed -37deg. Does this mean the probe outside the car is broken? I can't program the Speedo display to display the settings I want. Pressing and holding the BC switch on the indicator stem does nothing. I know the Speedo display works because it gives me the temperature when I start the car and the speed limit warning works fine. Any ideas? Quote Share this post Link to post Share on other sites
jochen 4 Report post Posted February 22, 2005 If the temp shows -37deg this means the temp probe is open circuit. You can check the probe with an ohmmeter - it should show some resistance (dunno how much) and change when you eg dip it in cold water then hot water. The probe is a simple thermistor - a resistor that changes value with temperature. You can also check that the temp display works by shorting the probe connector contacts and the temp should change from the negative maximum which it is now, to a positive manximum (prob above +50) The probe is the most fragile piece as it can get damaged in a frontal prang - my Mum's Merc has the same problem, but she's too cheap to fix it. J Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted February 22, 2005 the temp probe is near the "passengers " fog light in a big plug,sometimes because its relatively exposed that connectors getsa bit corroded and the resistance is enougn to upset the temp display.As far as not being able to program the display this maybe because of that temp probe problem,or are you getting any other error displays???,because that will prevent the obc display working properly,I think i have a link at home to show the fix for the fodlight/temp probe plug,watch this space tonite..... Quote Share this post Link to post Share on other sites
cainchapman 0 Report post Posted February 23, 2005 If the probe is faulty. Ask me nicely. I'm pretty sure I've got a spare one in my glove-box. Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted February 23, 2005 http://bmwe32.student.utwente.nl/ there is a link to -37 temp fix or similar on this page,it seems to be down at the moment it is acually am e32 site but the e32 and e34 share many such parts.As i said earelier,the temp at -37 is a warning so you cant display any other info till you have cleared that......the obc will <temp 3c> to warn of ice on the road,obviously -37 falls into the same caategory! Quote Share this post Link to post Share on other sites
ScD 0 Report post Posted February 23, 2005 Thanks for the replies I'll pull the temp sensor out in the weekend and check it out. I'd say your right about the ice warning kiwi, hopefully I'll get it sorted this weekend! Thanks for the offer cainchapman, I'll PM you to beg Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted February 24, 2005 check the connector that the wires from the temp probe and the foglights,that likely where the problem is. Quote Share this post Link to post Share on other sites
E34-535ti 5 Report post Posted February 24, 2005 Yes check the wires out of the probe, thats where my problem was, seems to be quite common..... Quote Share this post Link to post Share on other sites
