1994-2002 [Subscribe to Daily Digest] |
[Profile/Gallery]
, Sat, 6 Apr 2002 09:55:53
Members see ZERO ads on the bulletin boards and get more feature. - Help Keep This Site Online - Signup
I have seen oil level sensors on European vehicles, but not in N.A.
Hanyes says that the senor is on the back of the block, below the intake manifold. So you have to get under the vehicle to get at it.
The switch should be a closed at pressure. So an open circuit would indicate a wiring fault or low oil pressure. It might be the other way around, but then a connection problem would indicate that the oil pressure is fine, which would be really dumb. So the switch should be open when the engine is not running. The ECU should do a lamp check independant of the switch state. If the switch is faulty and closed at zero oil pressure, then the ECU might not light the lamp when the engine is not running, if the design allowed for this. If this were the case, removal of the connector at the sensor would then allow the lamp to light when the engine is not running. Hayes list the pressure switch at .3 to .5 bar of pressure, with a bar =~ 15 psi, the pressure is quite low. The don't say if the presure opens or closes the swith. If removing the connect makes the warning lamp go on, and touching the connector to ground makes it go out, that would indicate to me that the switch is closed at zero oil pressure that that seems wrong to me. If you don't get a warning light with the connector open, or to ground, then the lamp should be suspected. Running with the connector off should create a check engine or low oil message on the SID, if they have been as thorough as they are is must things of this nature. There might be a small vent hole to atmosphere in the switch body. If so, check that it is not plugged. If the above indcates that the fault is with the wireing or lamp. Connect a wire to the sensor and check for a connection to ground throu the switch with the engine not running, and when at idle. If the switch state does not change, something is wrong with the switch or the engine. If it does change state, then you will know for sure if it is open or closed with pressure. Done get under the engine with a meter while its running, unless you have proper stands and like noise and heat etc. There is some danger.
So, if the lamp does not light when you are on ignition, without cranking the engine, then the lamp is bad or wiring to it. The whole point is that this it a lamp check. So bulb burnt out and an oli pressure problem as the same time? Possible but not probable.
So this is something that you can do, you need a meter to measure ohms. etc This is basic, buy one if you don't have one. Radio Shack will do.
Also, with the ignition on, engine not running, ther should be a voltage at the connect to the switch while the switch is in a open state or the connector is removed from the switch. If there is not voltage there, then there is a wiring or ECU fault. The circuit supplies a voltage to the switch. If the switch is closed, this is connected to ground and the voltage drops to ground. There will be a resistance in the circuit in the ECU to provide current limiting. Years ago, there would be a powered relay coil and the switch would trip a relay, or close a circuit to just a lamp. But to do things just with a lamp required that the switch open with pressure which would not detect a wiring fault or disconnection of the senor lead etc. So again, the 'logic' should have changed over the years, but I have no hard evidence for this. Let us know what you find. You have enough info here to reverse-engineer the switch logic and narrow down the fault.
My dad picked up a small Fiat while working in Europe in the 70's. The pressure switch closed with pressure and the igniton ciruit was in series with it. So in cold weather, it could take a while to start as the ignition system would not work until the pressure came up while cranking. A neat idea, but a pain sometimes. I rented a nice 4 door Opel for a 4 week motor trip in Europe, and it had a senor on the dip stick and wiring to the dip stick.
posted by 209.172.20...
, Sat, 6 Apr 2002 09:55:53, Sat, 6 Apr 2002 16:33:53, Sun, 7 Apr 2002 17:23:38, Sun, 7 Apr 2002 17:16:59, Sun, 28 Apr 2002 17:47:15, Wed, 10 Apr 2002 00:11:42
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
