speed signal on 1997 312D ?

knopfler

Member
Hello

Some one know how speed signal is on 312D 1997? im thinking about up to speedometer cluster, is it same as Can and obd? or is it only power going from wheel sensor-ecu up to cluster?

im thinking to make a new digital speedometer cluster...

Victor
 

autostaretx

Erratic Member
Re: speed signal on 312D ?

Does your model use a CANbus to talk between the modules?

This is what the 2003 service manual says:
This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Controller Anti-lock Brake (CAB) over the Controller Area Network (CAN) data bus.
*and*
The CAB continually monitors the four wheel speed sensors to determine the vehicle road speed.
The CAB then sends the proper vehicle speed messages to the instrument cluster.

So it's the CAB pushing messages to the IC (instrument cluster)... the ECU doesn't directly get into the mix.

...at least here in the US...

--dick
p.s. the IC then goes on to create a pulsing signal to tell radios the vehicle's speed, so that they can/will increase the volume as road noise goes up. (IC connector C2, pin 9 going to radio connector C1, pin 1)
 
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knopfler

Member
Re: speed signal on 312D ?

no, here in europe we got t1n in early 90`s, and face lift (cdi) in 2000?or 2002. its not can bus on this model, but im wounder if there is somthing else like early can bus on this... cant finde repair manuals ore somthing like that to 312D
 

Cheyenne

UK 2004 T1N 313CDi
Re: speed signal on 312D ?

Hello

Some one know how speed signal is on 312D 1997? im thinking about up to speedometer cluster, is it same as Can and obd? or is it only power going from wheel sensor-ecu up to cluster?

im thinking to make a new digital speedometer cluster...

Victor
Victor,

It may not even be electrical, let alone CAN!!!

Reading page 94 of the old service manual here...

http://www.diysprinter.co.uk/refere...10_307_308_310_408_410D_service_manual_EN.pdf

It states to remove the Gearbox disconnect the mechanical speedometer drive cable.

SO first place to look would either be on your gearbox or on the back of the speedo head for a drive cable.

Keith.
 

knopfler

Member

autostaretx

Erratic Member
Re: speed signal on 312D ?

WDB9034621P713797
Fascinating.... i'm only starting the dig, but you (theoretically) have a 1-day/2-drivers recording tachograph, ABS and ABR, 4-wheel drive and "basic fittings for a radio" (so you may have the speed-pulse signal presented on a connector)

Here's your datacard: View attachment 1997-wdb9034621P713797.pdf

Oh, what fun.... here is the schematic and legend for your instrument panel: View attachment 1997instruments.pdf
(yes, the MB stupid software issues the pages in backwards order... "cut and tape")

The sensor for the speedometer is item G4 at (lower horizontal scale) location 76.
(engine RPM is B72 at location 60)
Connector X41 is the speedometer connector, and X49 is the speedo calibration and seal connector.
(note that X49 shows up elsewhere)
((i thought that the fuel level sensor (B3) came in X41 at location 46, but that's really X4.1))

The "tachometer sensor" can enter by either X41 or X49... so you'll have to look at yours.
The drawing says that X41 is only a 2-pin connector (with twisted wires to the sensor)
X49 has many pins (note the zig-zag line on the edge of the shell, indicating "more elsewhere")
"tachometer" is the generic term for anything that measures something rotating.

Wire color codes are in German, so "sw" (swartz) is Black.
The speedo sensor looks like a simple coil pickup (i'm trying to find it elsewhere)
Found it: it's MB part number A 005 542 58 17 "sender unit, speedometer"
Item number 53 in the diagram below my signature (scroll all the way down for the image)
((the drawing hints at a 4-wire cable))

M111 (not listed in the Legend) is the engine wiring harness

Given the datacard, here's the schematic for the "flat tachograph": View attachment 1997tachograph.pdf
Here the (a?) speed sensor seems to be G3, but the "speed sensor connector" is J149 at location 12, which corresponds to the mess at location 70 on the instrument cluster drawing. I'm not sure if that's an input or output from the IC. (i suspect it's an output from the IC, and that G3 is a redundant/confirming sensor for the recorder)

have fun
--dick
1997speedo.png
 
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knopfler

Member
Re: speed signal on 312D ?

Fascinating.... i'm only starting the dig, but you (theoretically) have a 1-day/2-drivers recording tachograph, ABS and ABR, 4-wheel drive and "basic fittings for a radio" (so you may have the speed-pulse signal presented on a connector)

Here's your datacard: View attachment 91412

Oh, what fun.... here is the schematic and legend for your instrument panel: View attachment 91413
(yes, the MB stupid software issues the pages in backwards order... "cut and tape")

The sensor for the speedometer is item G4 at (lower horizontal scale) location 76.
(engine RPM is B72 at location 60)
Connector X41 is the speedometer connector, and X49 is the speedo calibration and seal connector.
(note that X49 shows up elsewhere)
((i thought that the fuel level sensor (B3) came in X41 at location 46, but that's really X4.1))

The "tachometer sensor" can enter by either X41 or X49... so you'll have to look at yours.
The drawing says that X41 is only a 2-pin connector (with twisted wires to the sensor)
X49 has many pins (note the zig-zag line on the edge of the shell, indicating "more elsewhere")
"tachometer" is the generic term for anything that measures something rotating.

Wire color codes are in German, so "sw" (swartz) is Black.
The speedo sensor looks like a simple coil pickup (i'm trying to find it elsewhere)
Found it: it's MB part number A 005 542 58 17 "sender unit, speedometer"
Item number 53 in the diagram below my signature (scroll all the way down for the image)
((the drawing hints at a 4-wire cable))

M111 (not listed in the Legend) is the engine wiring harness

Given the datacard, here's the schematic for the "flat tachograph": View attachment 91417
Here the (a?) speed sensor seems to be G3, but the "speed sensor connector" is J149 at location 12, which corresponds to the mess at location 70 on the instrument cluster drawing. I'm not sure if that's an input or output from the IC. (i suspect it's an output from the IC, and that G3 is a redundant/confirming sensor for the recorder)

have fun
--dick
View attachment 91419
omg! what a job u did for me there! tnx a lot!
finally i get som information.i have Mercedes program on this computer but i dont understand is so good yet..i have to work with it...

first thing im thinking is that i actually can fit IC from my spare car, 2002 model. im going to move over dashboard from it to fit in my 312... but my first consern is Can-bus on 2002 model, that will make some trouble for me. but some way i have to figure out how i can make it work with out moving over wiring from 313, and if i have to move it, how to splice it together with wiring and ecu on 312... i think that both ecu have to share things like temp sensors, oil pressure sensors etc.

and if it not goes my way i have to build my own Ic..

what do u think about my thought on this?

and again, thanx a lot for all of youre help!

Victor
 

autostaretx

Erratic Member
Re: speed signal on 312D ?

what do u think about my thought on this?
... i think your project will prove very interesting...
(using the British definition of the word)
((similar to the Chinese curse: "May you live in interesting times"))

Please keep us informed of your progress...
and again, thanx a lot for all of youre help!
My pleasure :cheers: ... i learned quite a bit about the differences in the 1997's way of doing things.

have fun
--dick
 

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