| Author | Message | ||
     Nigel Parker Experienced User Username: trawler Post Number: 15 Registered: 9-2011 |
Morning everyone,on my Turbo R(97),the cruise control is now starting to be intermittent.It works initially but over a period of time if speed changes or braking is carried out then sometimes it will not re-engage.Any ideas???All other engine parameters and operation normal.Cheers Nigel | ||
| Jan Forrest Prolific User Username: got_one Post Number: 286 Registered: 1-2008 |
I would strongly suspect an electrical fault. Most likely a bit of corrosion at a block connector. | ||
| Omar M. Shams Prolific User Username: omar Post Number: 214 Registered: 4-2009 |
Dear Nigel, On my 1991 Turbo RL, I have the same issue and the cause is the module below the steering column. My car is a LHD model. The lucky Aussies can go to their local scrap yard and get one from a Holden V8 that I am advised is identical. I have learnt to live with my module in the dead state. The cost of repair is not worth me doing anything about it. | ||
| Brian Vogel Experienced User Username: guyslp Post Number: 44 Registered: 6-2009 |
Gentlemen, The Cruise Control - Repair or Swap? thread on the Rolls-Royce and Bentley Forums site might be of quite a bit of interest to you. Brian | ||
| Omar M. Shams Prolific User Username: omar Post Number: 215 Registered: 4-2009 |
Big time interest Brian. Many Thanks Omar | ||
| Nigel Parker Experienced User Username: trawler Post Number: 18 Registered: 9-2011 |
Thks Brian. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2462 Registered: 4-2003 |
Nigel’s car is a 59,000-series car, and has a different controller from that of a 20,000-series car. They changed at 57,000 and again at 59,000, so I have no idea if this is at all relevant to that car. One source of trouble is the speed pulse sender on the transmission, although I am unsure whether this applies to cars with the 4L80E transmission. They tend to attract moisture such the small PCB inside corrodes and the signal weakens. They are repairable, and fitting a new transistor (a PN100) and diode (EM513) is always a good idea too. The sender is worth eliminating as a fault because it is a cheap and easy repair. Then there is the dreaded ECU of which I have had four. Yep, those Siemens/VDO things are rubbish. The first I replaced with a new one from an Opel Omega (about $700 in 2001, VDO part 412.212/003/002). It works fine, but needs its gain changed to stop jerky engagement and some hunting (I now know how to correct the hunting after subsequent fiddling with a unit bought for testing). The Opel unit being new at the time and my only one, I didn’t want to experiment with it so in 2002 I bought a secondhand one (genuine Crewe type VDO412.212/004/001) for about $500 and it lasted two days. Back in went the Opel one, and it did its job for years but not as it should have. Back in 2003 and expecting the Opel unit not to last forever, I scrounged around some seconhand BMW spares outfits and bought a BMW unit to play with as it looked similar and has a similar VDO part number. The results are excellent although I haven’t needed to apply the solution permanently yet. Last year I bought an exchange one from Holland for EUR180, sending them my 2 day wonder from 2002, and it is fine a year on. I was going to try the well-known US outfit, but they dropped the warranty and trebled the price after bad experiences. Coincidentally I see the article referred to by Brian, and can confirm most of what is written especially the pinouts. I was pleased to see that he worked out the same solution to the hunting that I had. The author there used a VDO 412.212/005/002 (BMW part 1 384 734). I have one on test using a VDO 412.212/011/001 (BMW 1 387 625) which has a more suitable case. These are used on various BMWs around the early 1990s eg E30, E32, E34, E36 etc. The tuning resistor I use is 120k as opposed to the 100k mentioned in the text, however there is little difference. The tricky bit is to find some suitable plugs to make up an adaptor as I do not wish to cut and solder looms. In the meantime the Dutch unit is fine, but when it fails at least I have Plans B (BMW) and C (Opel) covered. As the Opel unit is a plug-in replacement, and given the unreliability of these VDO units on all brands of cars, I am reluctant to modify it, rather keep it as a working spare. The only other car which I know of using the exact Crewe part is an Alfa Romeo, a 164 of around 1990 I believe. RT. | ||
| James Feller Prolific User Username: james_feller Post Number: 174 Registered: 5-2008 |
theres is a reason you are a grand master Richard........ amazing! BTW and im going to touch wood....my cruise in my 89 turbo, which I use all the time, has never given me a days trouble, engages straight away, resumes perfectly and accelarates accurately too...being the age the car is now the only thing I do miss re the cruise on my Big B, is the deceleration function now on modern cruise control fitted to modern cars. Meaning that to slow down a bit you must either hit the brake or the cancel button then hit set again to the desired speed....ohh well not too much of an issue really on a 21 year old car... | ||
| Udo Hoffmüller Frequent User Username: udo Post Number: 79 Registered: 2-2008 |
Dear Richard, I would like to overhaul the speed pulse sender on my TurboR fitting new diode and transistor. Which alternatives would you recommend instead of PN100 - BC357? 2N2222? Best regards and Happy New Year - Udo | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2468 Registered: 4-2003 |
Hi Udo, The PN100 is an NPN. The BC357 is PNP and will not work. A BC347 will do. The 2N2222 is an NPN but has has a TO-18 metal case - a slight disadvantage. The type is not critical as long as it is a low-power NPN suitable for switching and amplification. The PN2222 is a TO-92 version of the 2N2222 - cheaper at 5 cents (!!!!) and better. Greetings from CH. RT. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2469 Registered: 4-2003 |
Speed pulse sender: diode (EM513, 1N4007 etc) and NPN transistor.  | ||
| Udo Hoffmüller Frequent User Username: udo Post Number: 81 Registered: 2-2008 |
Thank you, Richard. I have some BC337 left. The values are close to PN2222, so it should do? By the way, I will be in Genf about second half of April, I hope by car! Are you in CH then? Best regards - Udo | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2470 Registered: 4-2003 |
Hi Udo. The BC337 is fine. I shall be in Zh and GE around then. I hope that we may catch up. Richard. | ||
| Omar M. Shams Prolific User Username: omar Post Number: 217 Registered: 4-2009 |
I have just bought a BMW cruise control unit from a 90s 7 series car. The number is 412. 230/1/03. Will the wire loom that I need to make be the same as per the link that Brian kindly sent us above? In other words are the pins on the BMW units the same for all their modules? Thanks Omar | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2471 Registered: 4-2003 |
Indeed, Omar, they are standardised on BMWs. I hope that you bought the plug and a bit of the BMW cable with the module to make life easier when splicing the cables together. That way you may leave the Crewe plug in place paralleled to the BMW plug. I'll post some pictures when I return to Australia in a week or so. RT. | ||
| Omar M. Shams Prolific User Username: omar Post Number: 218 Registered: 4-2009 |
Dear Richard, Many thanks for the reply. No I did not get the cable as I got the module from Ebay. I do however have a scrap module from one of my old Bentleys and I was hoping to take the socket off that one. Happy new year to you and all the good people on this forum. Omar | ||
| Omar M. Shams Prolific User Username: omar Post Number: 221 Registered: 4-2009 |
Oh dear!!!! My BMW unit looks different on the inside to the one shown in the link above. I dont know how to identify the pins nor which resistor to change. In the words of my 9 year old daughter when she was 4 - "what me do now?" Thanks | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2472 Registered: 4-2003 |
Omar, Yours is for mid-late 1990s BMWs, eg an E39 5-Series. I assume that it has the black casing with the socket on a long side rather that on the end like a Crewe, Opel or BMW E38 etc unit ?? However, the plug is probably the same as the one in the link ?? If so, then the pinouts in the link above will be correct. You could always buy one the same as in the link (E38: VDO 412.212/005/002 or a VDO 412.212/011/001) with a plug and pigtails. I can put you onto an outlet in the USA which will sell you them for about $30 plus $10 shipping, but you may do better on eBay. RT. | ||
| Omar M. Shams Prolific User Username: omar Post Number: 222 Registered: 4-2009 |
Dear Richard, Yes you are right it is. I now know the pin out details thanks to you. What about the resistor? It is not a big deal - I will live with the snatch effect if it is too hard to identify. Thanks for your support Omar | ||
| Udo Hoffmüller Frequent User Username: udo Post Number: 82 Registered: 2-2008 |
You are always talking about BMW, but the ECUs have the wrong plug. Why not buy the one from OPEL Omega or Monza, they are exactly the same as the ones for RR. Even our workshop manual recommends those ECUs from General Motors. There is no problem to fit them because of the matching plug, only difference is fixation with only one instead of 2 screws. Regards - Udo | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2473 Registered: 4-2003 |
Udo, I have one of the Opel ones (VDO 412.212/003/002) which I bought new from an Opel dealer. They are almost the same as the Crewe item (VDO 412.212/004/001), but snatch on take-up more than do the BMW ones. That is why I had a spare Crewe unit repaired in the Netherlands. Of course, the enormous advantage of the Opel unit is that it has the correct socket even if the internals are slightly different. The Opel ones are harder to find than the BMW ones, even in Europe. In fact, I have never located a secondhand Opel unit, but you may have more luck with your German connections. RT. | ||
| Udo Hoffmüller Frequent User Username: udo Post Number: 83 Registered: 2-2008 |
Richard, I bought 3 Opel Omega ones within four weeks on Ebay. One has been repaired in Netherlands, but the job does not convince, it does not work properly, even after having sent it back for a second repair. In the meantime I got a list of all the capacitors and resistors fitted to try my own overhaul. But I am still playing around with other toys. Regards - Udo | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2474 Registered: 4-2003 |
Great Udo. What keywords did you use on eBay ? I tried Tempomat Opel Omega Monza Senator etc and have never found anything. I also tried 412.212/003/002 and GM90213458 I shall buy a few if I can, saving splicing a BMW plug to the loom when my Repaired in the Netherlands module fails (it has always worked perfectly so far). I know which resistor to alter on the Opel board, but do not wish to alter the one I have as it has only been used a little since new. When I used the Opel module (unaltered), the take-up was snatchy. Worse, it hunts as you go over a crest, which is particularly unacceptable on the motorway. The control loop gain is about 6dB too high, hence the need to adjust the (loop feedback) resistor. On test, the BMW module behaved acceptably on the motorway, although take-up was still a little snatchy: changing the resistor is still a good measure. Incidentally, the BMW printed circuit board is slightly longer than the Crewe and Opel ones, but the extra length is not used for any functionality as there are no components mounted on the extra available tracks. RT. | ||
| Udo Hoffmüller Frequent User Username: udo Post Number: 84 Registered: 2-2008 |
Dear Richard, many people on Ebay are stupid and offer simply "Steuergerät Omega", nothing else. So I put exactly that but "-LWR -Getriebe -Glühlampen ...", 30 or more things I do not want to be found. Left I get some 50 offers easy to check. The same with Senator. But at the moment there is nothing offered on Ebay. One can be found on "MercadoLibre" which is like Ebay in Brazil, but they did not want to send it to Europe. Imbéciles! You are right as far to the harsh take-up of the Opel unit. The one I use is very aggressive while the Bentley one is very lazy - it takes 3 seconds to answer after pushing the button. Can that be altered? I do not understand too much of this kind of electronics. Best regards - Udo | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 2475 Registered: 4-2003 |
Udo, thanks for the keywords. Rather than suggesting that you experiment with your ECUs or I with my Opel unit, I’ll try to buy one or two and have them shipped to a relative’s address in Germany if sellers will not ship to Australia. The Swiss Zollamt is far too aggressive, and charges MWSt (GST), customs duty and CHF35 (A$35) handling on all mail imports over $50. At least in Australia the threshold is $1’000 and the GST (Australian MWSt) is only 10% with no handling charges if you do exceed $1’000. Then I can set one up with a potentiometer again to tame it and report the findings. Incidentally, with the Opel ECU I played with some mechanical solutions: fitting preloading springs and damping at the actuator and along the linkages – with no luck. I can tolerate the aggressive take-up, but not the motor hunting 500RPM up and down as you glide over a crest at 120 km/h. The associated clunking of the drivetrain backlash is not too bad, but still not acceptable. I am sure that I can tune the ECU along the lines of my earlier experiments with the calibration resistor on a BMW ECU, but please be patient ! Thanks again, RT. |
