OVP circuit diagram help
 

Here's a diagram for the OVP on a W201 190E 2.5/2.3 16v with ASD (twin fuse).

Might be handy for people.

Anyone know what that symbol is for whatever it is that pin 9 (far right) connects into?

looks like ===><===/

Is it just a switching relay?

I have a large resistance in between pins 9 and 7 (with ignition on and off) and i believe it should be a closed circuit (at least sometimes).

thanks electronics buffs

Russell

That symbol shows the relationship between the solenoid and the contacts for the relay in question. The box with the slash through it is the solenoid, of course.

OK So it's basically, that solenoid (box with slash) flicks that switch on the right of it?

cheers

Russell

I could be wrong here - but 9 and 7 are never connected to each other.
Looks like on the load side of the fuse, 9 is only connected with 6.
7 and 2 are on the load side of the other fuse.
6 and 9 are connected to one relay, and 7 and 2 the other.
1 appears to be power that feeds both pairs of loads.

Well that doesn't make any sense. Here's the rest of the circuit diagram.

Basically I have an ASD problem. The stored error says it's the Stop Lamp Switch or Solenoid Valve (i.e. the error is on pin 10).

Tested Stop Lamp Switch, it's fine.

The Solenoid Valve test says you test for approx 6 ohms between pins 10 and 14 on the ASD computer. I get 20 kOhms yet the solenoid itself shows the required 6 ohms. As you see the circuit includes the stop lamp switch and OVP. So the OVP MUST be connecting its pins 9 & 7 :confused:?


Russell

With a voltage applied to pin 5, both relays should close, connecting both pins 9 and 7 to pin 1 through their respective fuses. So, they should be connected together, which means that if 12V appears at pin 1 it should also appear at 7 and 9.

Steve

Aaaahhhh...

I am with you.

Thanks for everyone's help, I have got somewhere with it now.

Since I was sure my problem was due to some break between pins 9 & 7, I have bridged them with a wire (making sure that this is safe!).

The ASD works perfectly now, and as a side effect the dodgy idle/starting is fixed and also the poor throttle response/running I was getting.

This makes me happy :).

The problem now is to work out whether the problem is in the OVP, that is not making this connection between pins 9 and 7, or whether it is not getting a signal to from pin 5....

I need to test another OVP really but don't want to buy one if mine is fine.

Hmm just had a thought :wacko:, off to test the voltage at pin 5 :D.

I'm sure no-one is reading by now, but I hope this will serve as a good bit of diagnosis to have in the archive....


Russell

Anything about ASD you can add to forum is good:cool:

I, for one, am paying attention ;)