E30 -90 problems with the instrument housing

[E30REDD]

Hello, I will try to be short in my words because my english vocabulary is far from good.

My E30 is from the beginning a 316i -90 but in 2012 the last owner changed the engine to a 318is.

My temp gauge is not working and there are some wires cut in the engine compartment: http://i49.tinypic.com/w06w04.jpg
I don't know where these wires should be connected but I'm concerned about they're being cut off.

I've disassembled the cockpit house and measured the Lithium batteries to 2.9V each. The SI-board has no signs of damage such as burned areas or exploded capacitors.

As you know the temp sensor is located in the engine head, on a very stupid spot which is under the induction, which means you have to disassemble the induction in order to reach the temp sensor.

The economy gauge is completely dead but the rest of the gauges works.

[Grrrmachine]

As a start, the plug in your photo is called the C101, and its pinouts are here:

http://www.e30zone.net/e30zonewiki/index.php/C101

As you can see, the brown is responsible for temp signals, which looks to be connected in that pic although crimp connectors aren't the best solution.

[E30REDD]

As a start, the plug in your photo is called the C101, and its pinouts are here:

http://www.e30zone.net/e30zonewiki/index.php/C101

As you can see, the brown is responsible for temp signals, which looks to be connected in that pic although crimp connectors aren't the best solution.

Oh thank you, that picture is very needed but are you sure that's the right picture of it because my C101 have a pacman symbol in its middle.

I forgot to mention one thing; I have tried to reset the service indicator light by short circuiting pin 7 and 19 while having the ignition ON but the lights never change.

[Grrrmachine]

The plug with the pacman in the middle is the Diagnostic plug:

http://www.e30zone.net/e30zonewiki/inde ... ostic_Plug

[E30REDD]

White/Black seems to go to the Diagnostic Connector and that should be why I can't reset the service indicator, right?

I'm confused becuase in the Motronic you linked there are two cables with the same color:

14 Black/White Speed signal out
16 White/Black Diagnostic connector

Black/White and White/Black is the same color in my eyes. :p

[Grrrmachine]

Black/White means Black with white stripes. White/Black is white with black stripes. You'll see a difference if you have both of them next to each other.

If your speedo is working it suggests pin 14 of the C101 is wired up correctly.

[E30REDD]

Black/White means Black with white stripes. White/Black is white with black stripes. You'll see a difference if you have both of them next to each other.

If your speedo is working it suggests pin 14 of the C101 is wired up correctly.

Yep, my speedo is working.

I tried to turn the ignition on and press my gas pedal 5 times but the service indicator lights are still lightning in yellow and red, as usual.

Also Green/White (Reset service lights) are cut off so no wonder why it doesn't work to reset the service indicator...

[E30REDD]

I'm going to bed now but I will be back tomorrow. Thank you for your time!

[Grrrmachine]

I tried to turn the ignition on and press my gas pedal 5 times but the service indicator lights are still lightning in yellow and red, as usual.

The 5-pedal-press technique is to get the "CHECK" light to flash error codes from the ECU. It has no connection with the red/orange/green service indicator lights, and it only works on US cars. The "CHECK" light only exists on cars with M20 engines and the overheard check control panel.

I think you need to get your soldering iron out and fix that loom properly before we try any more trouble-shooting.

[E30REDD]

I tried to turn the ignition on and press my gas pedal 5 times but the service indicator lights are still lightning in yellow and red, as usual.

The 5-pedal-press technique is to get the "CHECK" light to flash error codes from the ECU. It has no connection with the red/orange/green service indicator lights, and it only works on US cars. The "CHECK" light only exists on cars with M20 engines and the overheard check control panel.

I think you need to get your soldering iron out and fix that loom properly before we try any more trouble-shooting.

I'm a bit confused since there are very little space in the engine bay, so it's kind of hard to see where all the cables are connected. Well, the White/Black cable is cut off from the plug that's docking with the C101. Does this mean there should be comming a Black/White cable from the engine? It doesn't make sense to me.

I.e. all the cables that are comming from the plug that docks into the C101 are comming from the engine?

This is my engine bay:
http://i45.tinypic.com/28laruh.jpg
http://i45.tinypic.com/2814uo4.jpg

[Grrrmachine]

Yes, the C101 links the engine to the rest of the car. The engine loom also includes the ECU - that's why you've got a big lump of cables running along your bulkhead to the battery. Behind the battery the rest of the wires go to the ECU. On the other side of the C101 plug your loom goes to the fusebox, and under the fusebox to the rest of the car.

This is a standard engine loom from a Motronic 1.3 car (your original 1.6i):

http://www.e30zone.net/e30zonewiki/inde ... ngine_Loom

With the C101 pinout, that should show you where each wire goes.

[E30REDD]

Yes, the C101 links the engine to the rest of the car. The engine loom also includes the ECU - that's why you've got a big lump of cables running along your bulkhead to the battery. Behind the battery the rest of the wires go to the ECU. On the other side of the C101 plug your loom goes to the fusebox, and under the fusebox to the rest of the car.

This is a standard engine loom from a Motronic 1.3 car (your original 1.6i):

http://www.e30zone.net/e30zonewiki/inde ... ngine_Loom

With the C101 pinout, that should show you where each wire goes.

Oh god, so somewhere in the loom the White/Black cable is cut off? How should I be able to find it?

Is the White/Black cable from the C101 plug going straight to the EMU -> diagnostic plug, or is it going from the C101 plug straight to the diagnostic plug?

[Grrrmachine]

The important thing is not to look at the wire colour, but to see which pin it goes to in the C101. Because you've changed engine management system, it may be that you don't need that wire installed.

Which pins on your C101 have loose wires?

[E30REDD]

The important thing is not to look at the wire colour, but to see which pin it goes to in the C101. Because you've changed engine management system, it may be that you don't need that wire installed.

Which pins on your C101 have loose wires?

How should I do to be able to see where the wires are connected in the C101? Is the rubber on the C101 removable?

[Grrrmachine]

Yes, you can peel back the rubber from the C101. You can also use a multimeter for a basic continuity check, or a small battery and bulb.

[E30REDD]

Yes, you can peel back the rubber from the C101. You can also use a multimeter for a basic continuity check, or a small battery and bulb.

Oh, of course I can use a multimeter. Why am I so stupid... I will come back tomorrow with updates!

[Brianmoooore]

Do you know why the engine loom has been molested? Did the engine and engine loom come from something other than an E30?
This wiring diagram of the whole engine loom may help you, although it doesn't give the C101 pin numbers: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig02.pdf

[E30REDD]

Do you know why the engine loom has been molested? Did the engine and engine loom come from something other than an E30?
This wiring diagram of the whole engine loom may help you, although it doesn't give the C101 pin numbers: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig02.pdf

Thank you

I have no idea where the 318is engine came from, nor do I know why someone would cut the wires in the loom.

[E30REDD]

Okay, here's the update:

Cables that are cut off from the C101 connector:
Blue..................Charge light...................1...................Working
Brown/Purple.....Temp gauge...................4...................Not working
Brown/Green......Oil pressure light..........5...................Not working
White/Green.......Oxygen sensor..............6...................?????
Green...................Switched power............7....................?????
White/Green.......Reset service lights.....11...................Not working
Green/Purple......Fuel pump relay...........13...................Engine runs good so this is working?
White/Black........Diagnostic connector....16..................?????


Cables that are cut off from the Loom:
Red/Yellow.........ABS
White...................This is in some way connected with the 1 in the C101.
Green/Yellow.....This cable is coarser than the others, I guess this cable is around 2.5 mm2.

I would also like to mention that every cable that goes into the C101 has been cut off and then someone have jointed all of the necessarry cables back.

[Grrrmachine]

Your charge light should come on if you turn the ignition to the second position, and go off as soon as the engine is running. Is that not working?

[E30REDD]

Your charge light should come on if you turn the ignition to the second position, and go off as soon as the engine is running. Is that not working?

Yes, the charge light (battery symbol) is working just as you describe it.

[Brianmoooore]

Below is a table I drew up many years ago when fitting a M50 (24 valve, six cylinder engine) into an E30. The first part of each line, up to the part in brackets, is probably irrelevant to your problem, but from there on it tells you what each wire is for, the pin in the C101, and the colour of the wire.
For example, pin 2 on the E30 C101 is a green/yellow wire and is used for engine oil level. It won't be used on a four cylinder loom.
Note that these are the colours on the engine loom side of the C101. The colours on the body loom side are different in a few cases.
M50 1/ blue/white (dynamic oil level) E30 2/green/yellow
M50 2/ blue/yellw (static oil level) E30 10/blue
M50 /3 red/white (ABS) E30 20/ red/yellow
M50 4/ black/blue (aircon) E30 not used
M50 5/ black/grey (aircon) E30 not used
M50 6/ purple/grey (aircon) E30 not used
M50 7/ black/purple (drive away) E30 not used
M50 8/ grey (engine check light) E30 12/ grey
M50 9/ NC
M50 10/ NC
M50 11/ brown/yellow (water temp) E30 not used
M50 12/ brown/purple (water temp) E30 4/ brown/purple
M50 13/ green/purple(fuel pump) E30 13/ green/purple
M50 14/ black/white (speed) E30 14/ black/white
M50 15/ black/green ( unloader relays) E30 15/ black/green
M50 16/ white/yellow (Rx data) E30 not used
M50 17/ white purple (Tx data) E30 not used
M50 18/ black/yellow (starter) E30 18/ black/yellow
M50 19/ white/green (service reset) E30 11/ white/green
M50 20/ black (engine speed) E30 9/ black
M50 21/ green (ignition) E30 7 green
M50 22/ green/white E30 6/ green/white
M50 23/ brown/grey (oil pressure) E30 5/ brown/green
M50 24/ white/black (fuel rate) E30 8/ white/black
M50 25/ blue (ignition warning) E30 1/ blue

[E30REDD]

Below is a table I drew up many years ago when fitting a M50 (24 valve, six cylinder engine) into an E30. The first part of each line, up to the part in brackets, is probably irrelevant to your problem, but from there on it tells you what each wire is for, the pin in the C101, and the colour of the wire.
For example, pin 2 on the E30 C101 is a green/yellow wire and is used for engine oil level. It won't be used on a four cylinder loom.
Note that these are the colours on the engine loom side of the C101. The colours on the body loom side are different in a few cases.
M50 1/ blue/white (dynamic oil level) E30 2/green/yellow
M50 2/ blue/yellw (static oil level) E30 10/blue
M50 /3 red/white (ABS) E30 20/ red/yellow
M50 4/ black/blue (aircon) E30 not used
M50 5/ black/grey (aircon) E30 not used
M50 6/ purple/grey (aircon) E30 not used
M50 7/ black/purple (drive away) E30 not used
M50 8/ grey (engine check light) E30 12/ grey
M50 9/ NC
M50 10/ NC
M50 11/ brown/yellow (water temp) E30 not used
M50 12/ brown/purple (water temp) E30 4/ brown/purple
M50 13/ green/purple(fuel pump) E30 13/ green/purple
M50 14/ black/white (speed) E30 14/ black/white
M50 15/ black/green ( unloader relays) E30 15/ black/green
M50 16/ white/yellow (Rx data) E30 not used
M50 17/ white purple (Tx data) E30 not used
M50 18/ black/yellow (starter) E30 18/ black/yellow
M50 19/ white/green (service reset) E30 11/ white/green
M50 20/ black (engine speed) E30 9/ black
M50 21/ green (ignition) E30 7 green
M50 22/ green/white E30 6/ green/white
M50 23/ brown/grey (oil pressure) E30 5/ brown/green
M50 24/ white/black (fuel rate) E30 8/ white/black
M50 25/ blue (ignition warning) E30 1/ blue

Hello, I appreciate your help but isn't this list telling the same as yours: http://www.e30zone.net/e30zonewiki/index.php/C101

[Brianmoooore]

Same, apart from the wiki one has an error, which I shall now have corrected. Pin 4 is brown/purple, not brown.
You need to unplug the C101, and check that all pins have the wire colours that they should have, post up here what each wire connects to in the engine loom, and which wires, on the plug and in the loom, aren't connected to anything.

[E30REDD]

Same, apart from the wiki one has an error, which I shall now have corrected. Pin 4 is brown/purple, not brown.
You need to unplug the C101, and check that all pins have the wire colours that they should have, post up here what each wire connects to in the engine loom, and which wires, on the plug and in the loom, aren't connected to anything.

1 Blue
2
3
4 Brown/Purple
5 Brown/Green
6 White/Green x2
7 Green
8 White/Black
9 Black
10
11 White/Green
12 Brown
13 Green/Purple x2
14 Black/White
15 Black/Green
16 White/Black
17
18 Black/Yellow
19
20

There is a white cable from the Loom that is cut off right before the C101, but when I do a continuity check between that white cable and the pins on the C101, there are about eight pins that is connected with the white cable! :S

I have to mention that I opened the oil filler cap and it had some white smudge on it. That's an indication on water being blended with the oil, isn't it?: http://i48.tinypic.com/1h3x9z.jpg

Shouldn't there also be a lot of oil when you look into the oil filling hole? In my case there are no oil down there: http://i46.tinypic.com/fabx1v.jpg

The oil stick shows no indication of any white smudge. There is only clear oil on the stick.

I'm driving in fear because I don't know how hot my car runs so I would really want to get the temp gauge fixed ASAP because I'm using the car every day. I tried to measure the resistance of the Brown/Purple cable that is comming from the Loom. I measured between Brown/Purple and ground from the chassi but the multimeter was showing 0 Ohm all the time, it was completely dead.

[Grrrmachine]

Put your oil problems in a new thread in the Technical section, otherwise we will have lots of strange comments in this thread and it will get very confusing.

I would expect your car body loom to be ok. If you want to confirm it you will need to remove your instrument cluster using the guide in the Wiki, and then do a continuity check between the C101 plug and the corresponding pins of the cluster plugs. The cluster has three plugs connected to it (white, blue and occasionally yellow) and their pin-outs are all in the Wiki under "Wiring Diagrams".

Once you have confirmed that the car loom is intact, you can start fixing your engine loom. Your brown temp sender should only have one wire, so disconnect the sender from its plug and find out which wire it feeds on the C101.

Don't do continuity checks with everything connected, because you will get false readings.

[Brianmoooore]

All the wiring looks fine. If those pins are connected as you say, then everything should work.
There isn't a white wire in the engine loom of any E30 I've seen that comes anywhere near the C101, but whatever it is, it shouldn't be relevant to anything, since you've listed all the wires that are needed. Your brown wire on 11 should be grey, but it only used on cars with an emissions warning light, and the odd different coloured wire isn't unusual in BMWs.
Burning petrol produces large quantities of steam, and a small proportion of this finds its way into the oil, often producing a small amount of condensation in cooler parts of the engine, such as the filler cap, and no, you shouldn't see any oil when looking in the filler cap.

[E30REDD]

The oil problem seems to be solved so I won't create a new thread regarding that.

Let's start with the temp sensor; The sensor is located under the intake which makes it impossible to reach if I don't remove the intake. Therefore I was wondering if I could measure the resistance of the Brown/Purple cable (which should be comming from the temp sensor).

I did measure the resistance of the Brown/Purple cable but it showed 0 Ohm. I measured between Brown/Purple cable and ground from the chassi. If everything would be working properly the multimeter should've showed some resistance, right?

[E30REDD]

No thoughts?

[BenHar]

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot

There is a link to testing the blue sensor from that page.

Ben

[E30REDD]

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot

There is a link to testing the blue sensor from that page.

Ben

The blue plug is going to the ECU and it is working just fine. I have problems with the temp gauge, which should be the brown plug.

[Grrrmachine]

You should still be able to remove the wire from the brown plug without removing the intake. If you can do that, then measure for continuity along the wire between the plug and the C101. If you can't get it then you either need to find the break, or run a new wire.

[E30REDD]

You should still be able to remove the wire from the brown plug without removing the intake. If you can do that, then measure for continuity along the wire between the plug and the C101. If you can't get it then you either need to find the break, or run a new wire.

Okay, I will give it a shot. Just out of curiosity; Why are there two pins on the sensor? Wouldn't it be enough with only one pin?

[Grrrmachine]

Hmmm. Only the very old cars (Jetronic) should have a two-pin brown plug:

http://www.e30zone.net/e30zonewiki/inde ... ure_Sender

Pretty much everything after 1987 had a one-pin sensor.

[E30REDD]

Hmmm. Only the very old cars (Jetronic) should have a two-pin brown plug:

http://www.e30zone.net/e30zonewiki/inde ... ure_Sender

Pretty much everything after 1987 had a one-pin sensor.

You are totally right, I was thinking about the blue sensor... :p