Speed Sensor

[Jason_Leone at amat.com]

<<The L-jet in my Soob is giving a fault code 33 which corresponds to
a speed sensor in the workshop manual - I have pulled the dash out to
try and find it. The closest thing I can find is a 3" long plastic
strip with metal tabs at each end and a thing in the middle that kinda
looks like a high voltage light bulb. Is this the speed sensor? ii so
will just replacing it fix the problem or is the speed sensor somewhere
else that I haven't looked.>>

There are three different types of "speed sensors" on most Euro cars. One is the
Vehicle Speed Sensor (VSS), which is usually mounted to the tranny on FWD cars
(and sends pulsed signals to the ECU). This one is used for speedo readings, and
eliminates the need for a speedo cable. I doubt you car uses this!

The second type is the individual wheel speed sensor used on ABS equipped
vehicles. composed of a gapped wheel (or race) and a magnetic pick up. Every
wheel has this combo, if 4 channel ABS is present. Probably not applicable to
your car...

The third type often used is the engine speed sensor. This measures the engine
rpm (and can determine the angular timing of the crank, or position). Most are
composed of a 60 toothed wheel bolted to the crank, and a magnetic pick up
(sometimes an optical one is used). E30 model BMWs had a factory toothed crank
wheel/crank pulley that was outside the block. Late model VWs have an internal
toothed wheel bolted to the crank, inside of the block (flywheel end). VWs
happen to read TDC off of the trailing edge of the 13th tooth, other cars are
similar. This rpm signal goes to the ECU, get's processed...then the ECU sends a
different signal to the instrument cluster (Tachometer).

The engine speed sensor will be in the engine bay. If it's an internal crank
wheel, the sensor will be mounted into the block and will look like a knock
sensor...but will be mounted much lower in the block. If you have an external
crank wheel, it will be plainly visible off to the side of the crank pulley.

However, the L-Jetronic system might not have what I'm talking about. I'd have
to thumb through my Bosch FI book to figure that out. It's been awhile since I
owned one of those cars. =)

<<Car is a 1987 Leone RX Turbo>>

He he. Tell me more about this "Leone" car. Good name, I must say.

Jason
'93 SLC