Volkswagen coil driving

GodSquadMandrake · Post by **GodSquadMandrake** » Wed Apr 19, 2006 1:29 pm

bens_cab, how did you get the VR sensor to work? Please explain how it's wired up and which pins are hooked up to what.

GodSquadMandrake · Post by **GodSquadMandrake** » Wed Apr 19, 2006 8:06 pm

vlopsahl wrote:You brake the XG1 â€“ XG2 on the V3-board. Then you feed the signal in there through one spear wire on the DB37 . Then you fed pin 24 on the DB37 with 12V+. You also fed one of the three wires on the sensor with 12V+. The sensor then have 12V+, signal out (to directly to XG1) and ground.

Ok I did all that, and I had my board jumpered for hall operation except of course for the connection between XG1 and XG2. XG1 went to a spare wire and I tested it with my digital multimeter. I fed pin 24 +12v from the battery. I tried every relevent combination of wires on the connector I could think of, but I never got an RPM signal. I even tried all this in VR mode and nothing worked. I verified all my wires had connections with my digital multimeter. I'm still not getting an RPM signal. Is it possible my sensor is different somehow?

GodSquadMandrake · Post by **GodSquadMandrake** » Wed Apr 19, 2006 8:18 pm

This is what my crankshaft sensor looks like:

Bosch Part # 0251210121

I looked up the part on GermanAutoParts.com and this is what I got:

That one is different. It doesn't have the little button in the middle of the tip, it's solid metal as you can see. Also the connector is black and mine is white with the pins more closely spaced than the one shown. The connector on mine has a '1' on the flat part on the top, and a 'CB' on the flat part on the bottom.

jassem99 · Post by **jassem99** » Wed Apr 19, 2006 11:09 pm

GodSquadMandrake wrote:This is what my crankshaft sensor looks like:

From the picture I can't make out a slot along the side of the sensor, so it doesn't seem like a hall to me. To make certain, remove the sensor connector, check for +12V on the 3-pin connector when the ignition is switched on. If one of the pins (pin 1) has +12V then it would be a hall and the slot might be hidden and not visible in the picture you posted.

Basil

GodSquadMandrake · Post by **GodSquadMandrake** » Thu Apr 20, 2006 6:14 am

Basil,

I rebuilt this motor myself and I do not recall a slit on the side of that sensor. It is one piece with a little megnetic looking thing at the tip that faces the trigger wheel. I guess this explains why nothing I tried worked, it's a different sensor. It didn't work in regular VR mode either. Any ideas on hooking this sensor up?

I can pick up a different sensor from the junkyard on Saturday. I'll look for one with the slit. I have an autocross on Sunday. That doesn't give me much time to tune.

qbngolf · Post by **qbngolf** » Thu Apr 20, 2006 8:58 am

I think he is referring to a slit being in the toothed wheel. before standalone, my sensor crapped out, my original one i pulled out looked like the one in the bottom picture. the aftermarket one was the same exact one that you have in that block. i wouldnt waste my time going to the junkyard and pulling one out. big time pain in the a@@.

GodSquadMandrake · Post by **GodSquadMandrake** » Thu Apr 20, 2006 9:09 am

So the slit in wheel is probably for the HALL part to create the electric field or whatever. Mine obviously can only be a VR sensor. Good we have that much established then...

GodSquadMandrake · Post by **GodSquadMandrake** » Thu Apr 20, 2006 10:58 am

I just talked to my local Mad German Scientist again. He said that this sensor is a VR sensor that gives a hall like output. He showed me a VW wiring diagram from his laboratory that indicated that one of the pins is fed +5v, one is signal to the ECU, and one is ground. He said that will work as a HALL signal, but not as a VR. He said it "switches positive." So I guess it gives a square waveform. It must be filtered or something. I'll try this when I get home tonight.

jassem99 · Post by **jassem99** » Thu Apr 20, 2006 12:02 pm

qbngolf wrote:I think he is referring to a slit being in the toothed wheel. i wouldnt waste my time going to the junkyard and pulling one out. big time pain in the a@@.

Not really. The ABF wheel is the exact same one as the ABA one shown in the picture. The slit is in the body of the sensor itself. When the ABF crank sensor went bad, the only VW crank sensor that would start the car was the model with the slit along the side. That's my brief encounter with these VW crank sensors.

And i would agree about pulling one out being a PITA. Better to invest in a cheap scope to help you out.

And it would be helpful if you can check for voltages on the harness end of the crank sensor connector with the ignition on (just to avoid confusion let me say that i mean check for voltage between ground and each pin, rather than between the pins, so use engine ground or battery ground or the like for the negative DMM probe). That would determine if the (supposedly VR) sensor needs to be 'powered' to operate some sort of magic conditioning circuit.

Basil

GodSquadMandrake · Post by **GodSquadMandrake** » Thu Apr 20, 2006 1:15 pm

jassem99 wrote:And it would be helpful if you can check for voltages on the harness end of the crank sensor connector with the ignition on (just to avoid confusion let me say that i mean check for voltage between ground and each pin, rather than between the pins, so use engine ground or battery ground or the like for the negative DMM probe). That would determine if the (supposedly VR) sensor needs to be 'powered' to operate some sort of magic conditioning circuit.
Basil

Magic huh? lol. Not quite. The engine is going into a 1988 Jetta, while it is originally from a 1998 Golf. I don't have a real motronic harness or ECU in the car. I have some friends that do so I will try and see if they'll let me probe their cars for voltage on the ECU connector. That would answer a lot of questions.

It's interesting to know that the trigger wheel is the same between both cars. That means that I technically could switch the sensors. I might do that if I can't get this one to work. It isn't that much work. Just take off the motor mount and remove the 10 mm hold down bolt for the sensor...