Crank and Cylinder Index Sensors M70

[shogun]

and here clear pictures where the 2 CPS and the 2 CI are located on the M70 engine, pics from 8 eights, best is you mark all the sensors

[shogun]

what is the p/n of the female connectors for the CPS and cylinder identification sensors for the M70 engine, these are part of the engine wire loom, the counter parts where the male CPS and donut connectors go in. 2 white and 2 black 3-pin connectors/plugs . In ETK for E31 there is nothing shown, the E32 ETK shows under engine electric a 3-pin plug which could fit. Plug housing 12521706068 3 POL. NLA. google finds as replacement respect. old p/n : 12521706096, 12521706068, 12520492991, 12521358472, AMP 827578. Here a drawing from front of the plug http://www.e32-schrauber.de/bmw/date...or_Stecker.png
Did someone already replace such a plug and can confirm the p/n? On my website there are some good pics from page 22 - 26 of these plugs. http://twrite.org/shogunnew/files/fo..._Refurbish.pdf

[m6bigdog]

From my 5/95 Electrical Connector Repair Kit Listing - original 3-pin connector P/N: 90-88-6-706-096 Plug Housing 3-Pin with release device (black)
The 90-88-6 on these P/N was updated to 12-52-1.

I anticipate the 3-Pin plug housing will be the 12-52-1-706-096

[shogun]

Thanks for the confirmation, 12521706096 3-pin , Supersession(s): 12-52-1-706-096; 12521706068; 61131358472; 83300492991, seems to be a fault in the ETK, not listed at all for E31, used on many other cars in various places. Part Cross-reference 12521706096 Plug housing From: 06/01/1986 To: - , Supersedes: 83300492991 (09/25/1996 — 08/13/2007), Part 12521706096 was found on the following vehicles: E30, E36, E12, E28, E34, E39, E24, E23, E32, E38, Z1, Z3 E36

[m6bigdog]

Thanks for the confirmation, 12521706096 3-pin , Supersession(s): 12-52-1-706-096; 12521706068; 61131358472; 83300492991, seems to be a fault in the ETK, not listed at all for E31, used on many other cars in various places. Part Cross-reference 12521706096 Plug housing From: 06/01/1986 To: - , Supersedes: 83300492991 (09/25/1996 — 08/13/2007), Part 12521706096 was found on the following vehicles: E30, E36, E12, E28, E34, E39, E24, E23, E32, E38, Z1, Z3 E36

Yep, BMW can build them, but once out of production they can't tell you what's in them!!

I also see 3-pin Plug housings: Late model vehicles?
3-POL 12521732596
3-POL 12521732597
But I don't think those are what your looking for.

Since my first BMW I owned in 1990 (E34, M5) I knew BMW had problems with parts not in the parts catalog (microfiche - back then) and parts listed but not assigned to the series; even though the part was in the assembly.
Through the years, I have amassed all the Paper & CD parts catalogs, tool catalogs, Retail Price List, Service Bulletins, Service Manuals, ETMs, Training Manuals, TIS, DIS, etc, etc and/or what ever I could talk the local dealer parts counter guys out of (at some point they would give me all their old revisions) just so I had a fighting chance to identify the parts I needed to keep my BMW's original and new as possible. The first CD ROM TIS, ETK's, Technical Documents & Training Manuals (when paper phased out) was very expensive ($300 deposit/CD ROM & $50/revision) but worth every penny, as a DIY'er.
Good luck...

[rocae38]

Need help can’t remember Which plug goes to we’re?


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[8eights]

Donut and crank position sensor plugs orientation- facing from front of car:


Bank 1 donut sensor (pass.)- bottom left

Bank 2 donut sensor (driv.) - top right

Upper cps - top left

Lower cps- bottom right

[JDP530]

After insulating fuel rails this past weekend and re-assembling yesterday engine will not start. I have looked at all of the fuses I could find, including the heavy fuses on right side battery, and none of them were blown. Engine spins easily but it doesn't pop at all on either side. I haven't had anytime today to do any trouble-shooting, but I have been told that sensors on front of engine could be reversed. I am pretty sure I have wires plugged in same as before when engine ran fine because plugs are oriented to go in one way and I didn't change anything.

One factory diagram shows the sensor connectors (black and grey) in a different orientation than on my car, but, according to George Fontes article on his 750i top end rebuild, my connectors are in same position as his. But, my sensors on left side of engine are reversed compared to his. I haven't changed anything and I have compared plugs and connectors to old photos when I first started working on the car and I don't see anything different.

George (shogun?) shows both sets of sensor connectors on brackets positioned with black connectors on top and the tan connectors on the bottom. This is how mine are mounted. But, as I mentioned above, the cylinder ID sensor is mounted to top (black plug) on right side standing in front of car. According to his article, both cylinder ID sensors should be plugged into both the tan connectors.

So I am quite confused now! Is it possible that the alarm on my '91 model has disabled the ignition/ fuel system that is preventing engine from starting? Seems like engine should start on one bank even if sensors on other bank are reversed.

This first photo from a couple of years ago shows orientation of connectors that are still the same now.
Attachment 678201

This is photo showing orientation of colored connectors as they are today.
Attachment 678202

This photo shows orientation of sensor plugs. The top plug on left side of engine is the cyl ID sensor for 7-12. But, according to George, this plug should be plugged into tan connector on bottom like that on right side of engine. The bottom plug is the crank sensor plug.
Attachment 678203

Here is a factory diagram of the connectors which is different from those on my car and George's 750. This diagram shows grey connectors on one side and black on the other. The orientation of sensors is the same as those on my car though.
Attachment 678204

I would appreciate any help! Electrical diagnostics isn't my forte.

[ChrisFuture8]

JDP530, see if my picture help.

If you are in front of the car facing the motor, the passenger CID is plugged to the bottom on the passenger side. The driver's CID is plugged in the top position on the driver's side.Attachment 678205

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[JDP530]

JDP530, see if my picture help.

If you are in front of the car facing the motor, the passenger CID is plugged to the bottom on the passenger side. The driver's CID is plugged in the top position on the driver's side.Attachment 678205

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That's how mine are positioned same as yours. It's just that the connectors are not the same color as indicated in other photos and diagrams. In George's article he indicates that both CID sensors are plugged into the same color connectors on either side.

Is it possible my alarm in this '91 model could prevent the engine from starting?

[ChrisFuture8]

I don't think the 91 has the EWS module (the gurus chime in here if I'm wrong). Corrupted EWS module will prevent your starter not to turn among other things.
Are you getting fuel? Is the exhaust tip wet with unburned fuel? Are you getting spark when you crank? Do you have a spark tester?
Try pulling each fuel line at the injector rails (and placed the line into a glass jar and have someone crank the motor a few seconds to see if you're getting fuel.

At one time when both of the CPS sensors on my car went bad, the motor would not catch. If one is good and one is bad, the motor will start but run rich and extremely lumpy.
Trace back your engine wire loom from the plugs at the front of the motor to the injectors and back to the end of the motor. Make sure nothing was badly kinked when you lifted the wireloom off to get the injector rails out.

[shogun]

From my website, this shows how George marked the CPS and CI connectors on his E32 750 http://twrite.org/shogunnew/files/fo..._Refurbish.pdf he mentions from page 20:
Pulse Sender/Cylinder ID (right)
This is a view of the right side Pulse Sender [top plug ] (circled). This connector block is black and the cable goes to the left side of the block) The connector beneath it is the Cylinder Identifier (1 through 6 ) and leads to spark plug wire No. 6 on the right bank. This connector block is tan/white.

Pulse Sender/Cylinder ID (left)
This is a better view showing the left side Pulse Sender (top plug). This connector block is black and goes to the right side of the block) The connector block beneath it is for the Cylinder Identifier (7 through 12 ) and leads to a spark plug wire on the left bank. This connector block is tan/white

Pulse Sender/Cylinder ID : NOTES
To help me remember where the connectors went, I labeled a couple prior to unplugging. As you can see to the right, these unplug in the same manner as the temp. sensors on the intake manifolds. Squeeze the bail in and pull out the plug. Don’t cross these plugs when reassembling!

Cylinder ID
This view shows the right Cylinder ID plug with its “doughnut” around spark plug wire No. 6.

Pulse Sender/Cylinder ID connector Removal (Circled)
This shows the location of the four 10 mm (socket) bolts that hold the connector retaining clips to the cylinder head. They’re hard to see as they’re covered in grunge.

Connector Blocks in Clips This shows the bolts removed with the connectors (still held by their mounting clips.) I chose not to separate the connectors from the clips because I didn’t want to get them mixed up. I carefully threaded them under the oil filler spout when I removed the injector wire harness.

on page 26 is also a very good pic showing all 4 connectors.

[shogun]

Just to make sure, I now checked on 2 cars, 1 x on my 11/88 E32 750 pre-facelift engine and on a E32 Alpina B12 750 with facelift engine, both are the same. Same as explained in the site of George.
Black connectors are on top, white ones are on bottom, also look at the cable loom, the upper cable goes to the upper black plug on each side. Here a pic from the B12 where we just reseal the intakes.
And here are the pins and the measuring data on the pre-facelift DME M1.2 with Bosch end no. -156 , 55 pins http://www.europeantransmission.com/...out1988_90.pdf

[shogun]

more pics https://www.bmw-rudel.de/index.php/b...toren&catid=12
see picture nr 4
Nr.... Sensortyp......................................... ........Ziel/for
1......KW/CPS-Sensor Bank 1............................. DME1
2......KW/CPS-Sensor Bank 2............................. DME2
3..Zylinderidentifikationssensor/Donut Bank 2.......DME2
4.Zylinderidentifikationssensor/Donut Bank 1........DME1

shows cylinder nos, CPS, donuts, temperature sensors locations and Ohms, plug locations of CPS and dounts
explosion drawing M70 engine, https://www.7-forum.com/bild.php?bil...%20und%20sport

pic from adamnur https://imgur.com/VbyDkkH

and here a vid how to change, there you also see where which one goes https://www.youtube.com/watch?v=axdCIQS8gJw

[shogun]

M70 M1.2 55-pin DME pinout for 1988 - 1990 model 750iL E32 (NOT M70 M1.7 88-pin DME from 1990-..., for that you have to check the ETM in detail, but the technical data for testing below are the same such as MAF etc )
Pin 1 ignition pulse
Pin 2 ground shield for ignition pulse

Pin 8 cylinder identification sensor
Pin 31 cylinder identification sensor

includes all DME pinout specifications for voltages, grounds , continuity and resistances
Technical data grounds, battery supply, main relay supply, coolant temperature sensor, air temperature sensor, fuel pump relay, throttle switch, air mass meter, oxygen sensor, oxygen sensor heater, evaporative purge valve
http://www.europeantransmission.com/...out1988_90.pdf