[urq] no start - hall sender voltage never changes.

Buchholz, Steven Steven.Buchholz at kla-tencor.com
Tue May 10 21:07:28 EDT 2005

No, the Hall Sender should be in one state when the window is present
and the other state when the window is not present.  It is not like the
speed and reference signals which respond to a moving magnetic field.
You should be able to rotate the distributor to either of the two
conditions and see a stable signal.  The thing to be careful of is to
make sure you know which terminal is the one that is supposed to switch,
and verify that you have power and ground on the other two terminals.  

Note that the Hall sender is #5 on the IST no start troubleshooting
chart ... so you should have already verified that the F/TCU is getting
power (#1), Verify Ignition Control Unit function and coil (#2), verify
functions of reference and speed sensors (#3 & #4).  While I haven't had
any of the timing sensors fail on my urq, it is fairly common on my
other Audiction ... the V8Q.  On the PT engine the flywheel timing
sensors are a common culprit for no start issues.  That said, I too have
seen a Hall Sender go bad on a V8, but it is much less common.
Fortunately, since the V8 has an even number of cylinders, the ECU can
allow the engine to continue running when one of the timing sensors
(other than the speed sensor) fails.  

Steve B
San Jose, CA (USA)
> Hey guys, I had a no start condition on my car a month ago and it
cleared up
> after a few hours. No start returns, no spark at all.
> Ignition on, ohm meter probe in the middle wire of the hall sender,
> in, turn over the car with a socket wrench and stop at the window with
> change in voltage (8.5 volts).
> Turn over again with the socket wrench not pausing at the window like
a normal
> engine revolution and the voltage never went to zero or fluctuated.
> The window is supposed to lose voltage at that moment which triggers
the spark
> from the coil correct?
> So... I need rod to get me a hall sender.
> Is this correct? it is an 83 urq  manufacture date 3/82

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