mpg swingometer thingy !

[bigdek]

where does this get its reading from ?

i have tried 3 different sets of clocks in my m30 touring and it doesn't work.

didn't work before the engine swap either.

any ideas how to sort it ?

[Brianmoooore]

where does this get its reading from ?

i have tried 3 different sets of clocks in my m30 touring and it doesn't work.

didn't work before the engine swap either.

any ideas how to sort it ?

Gets road speed info from the speedo and fuel rate info from the ECU, all processed on the SI board.

[Ritchie]

Dek, my one was working before my m30 conversion and its not now. So im guessing the ecu isnt compatible with the e30 clocks. Im not that bothered about mine but if you do figure it out let me know!

[bigdek]

thanks for that m8.

hows the m30 powered beast running ?

[Ritchie]

Not bad, a few litttle niggles. Its developed a strange screeching sound from the rear nearside when its cold, sounds a bit like an air leak which is weird! although ive not looked to see what it is yet. The throttle cables a bit sticky which makes it a bit difficult to be smooth but ill get one from the stealer today. I still have to buy a standard backbox cos its WAY too loud! also ive still got to fit an electric fan and i put Ԛ£70 of optimax in it in 3 days but apart from that its ok!

[gareth]

alright lads!

i've just got my 335i touring running this weekend!!!!

if it helps, my mpg swingometer did work before and now does not! however i suspect the SI boards has gone on a munching mission too so that may have killed it.

[Brianmoooore]

was going to post that I've never heard complaints about this from another 335 owner, but now another one of you has.
The relevant pin on the E30 C101 is pin 8 with a white/black wire.
What do you have connected to this pin from the 3.5 loom?

[gareth]

hehe! it's a disease!!!

to be completely brutally honest, i have no idea where it's connected! i simply plugged the M30 (E32 735i) loom into the E30 325i loom. maybe there's a difference in the pin-outs?

do i assume C101 is the large engine loom to car loom bayonet connector?

[Brianmoooore]

C101 is the large round plug and socket just inboard of the fusebox.
Didn't realise that the 7 series loom has the same type of plug. It's a wonder that anything worked, as there's noreason why an E30 and E32 should have the same pinouts!

[Brianmoooore]

Been looking up some 3.5 E32 wiring diagrams.
3.5 ECU has a white/black wire from pin 32 which feeds the same info to the 7 series econ gauge and OBC, but don't know which pin it goes to on the 7 series engine plug, or if the signal is the same form as that on the E30.
Basically, you should have a white/black wire to pin 8 in both halves of the C101/
If it still doesn't work, then an oscilliscope is needed on the signal in your 335 and on the one in an E30.

[gareth]

it's quite remarkable really! the whole E32 loom just plugs in, a few wires need extending to reach the coil and pin 15 needs earthing to bypass the unloader relays (otherwise no lekky windows or fan when moving!) but so far everything works!

a bit of fiddling to get the instuments all working is fair enough but to be honest i can't see why they would wire everything differently. standardisation would make fault diagnosis so much easier for the dealers if everything is simple! there's no shortage of pins in that plug to route everything though...

[Brianmoooore]

Just been back to the circuits,and it appears the unloader relay on the E32 is worked by a contact that opens as the ignition switch is turned. Completely different to the E30.
Can be made to work properly though, by connecting pin 15 to the link strap between the starter motor solenoid and the motor itself.

[bigdek]

ok fellow 335 owners and owners to be

here is the fix !

ON my car anyway 91 325 touring

pin 3 of the e32/e34 engine plug ( white/black) needs to be connected to pin 8 (yellow/white) on the e30 side of the plug.

Working perfect now although the readings will bring a tear to your eye

[Ritchie]

Nice one! im a bit scared to fix mine though

[gareth]

Just been back to the circuits,and it appears the unloader relay on the E32 is worked by a contact that opens as the ignition switch is turned. Completely different to the E30.
Can be made to work properly though, by connecting pin 15 to the link strap between the starter motor solenoid and the motor itself.

interesting, i'm guessing this goes live while cranking? does this somehow latch the relay?

to be honest i've not yet even looked into how it all works, i only know that it didn't work right until i earthed pin 15 (cheers bigdek!). it now seemingly works fine...

ok fellow 335 owners and owners to be

here is the fix !

ON my car anyway 91 325 touring

pin 3 of the e32/e34 engine plug ( white/black) needs to be connected to pin 8 (yellow/white) on the e30 side of the plug.

Working perfect now although the readings will bring a tear to your eye

cheers mate, i'll give this a go at the weekend. i too have a 91 325i touring so fingers crossed...
did you move the pin position to mate up? do they unclip or will i need to get some spares from BMW?

[Brianmoooore]

The pins can be unclipped by pushing a very small screwdriver in from the back of the plug, but remember to bend out the little locking tab again before pushing it into the no 8 position.
The E32 white/black is the wire as bigdek says. Just transfer it to position 8 and all should work.
The E30 side of things can either be white/black or yellow/white according to my diagrams.
Pin 3 of the E30 C101 is unused
Regarding the unloader relays: One end of the relay coils is connected to 12V+, the other end connects to the "live" end of the starter motor, but when the starter is not being used, the windings are effectively a short circuit to earth, and the relays pull in. When the starter is engaged, there is 12V+ at both ends of the relay coils, i.e. 0V across the coils, so they drop out.

[gareth]

ahaaaa, got it. i've got a seperate wire running from the connector and off to an earth but it should reach the starter no problem.

cheers brian.

[gareth]

pin 3 of the e32/e34 engine plug ( white/black) needs to be connected to pin 8 (yellow/white) on the e30 side of the plug.

ok, i had a look at this earlier, expecting to find a simple mismatch in the pin positions. on my car, pins 3 and 8 on both sides of the connector have wires fitted.

in this case, to get things right before i start hacking, do you mean to run a link wire between pin 3 and pin 8?


while we're on the subject, is there anywhere online that i can get the wiring diagrams as the useless haynes manual is driving me totally barking!!!!!

[Brianmoooore]

pin 3 of the e32/e34 engine plug ( white/black) needs to be connected to pin 8 (yellow/white) on the e30 side of the plug.

ok, i had a look at this earlier, expecting to find a simple mismatch in the pin positions. on my car, pins 3 and 8 on both sides of the connector have wires fitted.

in this case, to get things right before i start hacking, do you mean to run a link wire between pin 3 and pin 8?


while we're on the subject, is there anywhere online that i can get the wiring diagrams as the useless haynes manual is driving me totally barking!!!!!

Interesting! I've never seen a wire connected to pin 3 of the body socket on an E30. What colour is it?
Don't know about the E32 plug, other than 3 is the white/black that you want.
What colour is the wire on 8 of the E32?

[Brianmoooore]

Some usefull wiring diagrams at www.autolib.diakom.ru:8001/CAR/BMW/

[gareth]

i'll have a better look later. it was getting dark, i disconnected the plug and found pins in all of the 3 & 8 positions. i'll have a better look later, i may have been wrong.

cheers for that link though, i've printed it all off!

[bigdek]

pin 3 and 8 on the e32 loom will have wires

pin 3 on the e30 loom wil be empty

remove pin 3 and 8 from the e32 loom and swap them around

so pin 3 is conncted to 8 and pin 8 is connected to nothing

[gareth]

i'll give this a go. cheers mate!

[bigdek]

well worth doin as i have definately made the last tank of petrol last longer

[gareth]

[gareth]

just to close this, i swapped the pins arounds as per bigdeks post and it all works fine...

sorted

[Bob_S]

Bit off topic but will the SI board affect my speedo then? cheers.

my service lights are showing last green, yellow and red plus inspection my mpg guage in 0 or infinite and my speedo is somewhat possessed as it sometimes reads sometimes not?

cheers

[Brianmoooore]

Bit off topic but will the SI board affect my speedo then? che

Not normally. Check the wires for internal breaks where speedo signal comes out of the diff.

[ant2]

right. bored of no heaters and no electric mirrors, whats the best way to earth pin 15 then, just run a wire out of the big plug and down to the starter ? or is there a beter way of doing this, just got my mpg meter working today aswell, not alot of point tho as it doesnt go past 15 mpg

[Brianmoooore]

Run a wire from the C101 plug down to the starter motor, and connect it to the link between the solenoid and the motor.