Camshaft and Crankshaft Sensors--I'M BACK

On Sun, 25 Mar 2007 06:54:20 -0500, "maxpower"
> wrote:

>
>"bllsht" > wrote in message
.. .
>> It doesn't take a scan tool to determine if disconnecting the knock
>> sensor eliminates the symptoms.
>>
>>
>>
>> On Sat, 24 Mar 2007 20:25:36 -0500, "maxpower"
>> > wrote:
>>
>> >
>> >"powrwrap" > wrote in message
>> oups.com...
>> >> On Mar 24, 12:23 pm, "powrwrap" > wrote:
>> >> > > On Mar 23, 11:36?pm, bllsht > wrote:
>> >> > > Not sure if it was on '97 models, but there was a TSB that dealt
>with
>> >> > > a problem like this. It involved removing the knock sensor because
>it
>> >> > > would cause the PCM to reset while driving.
>> >> >
>> >> > Hey thanks! I'll research it...
>> >>
>> >> Can someone that has access to Chrysler technical service bulletins
>> >> please post #19-34-98? I believe it is dated 11/27/1998. I found this
>> >> while searching Yahoo Groups. It may contain the solution to a long
>> >> running problem. Thanks.
>> >>
>> >
>> >18-34-98 is a TSB that requires disconnecting and taping the wire of the
>> >knock sensor for a symptom you are describing BUT this only occurs if the
>> >Module is resetting itself back to zero and all the learn values resets.
>A
>> >scan tool is required to determine if this is what is happening.
>> >
>> >Glenn
>> >
>
>No it doesn't. But the OP stated that it happens sometimes, a scanner would
>have determined that the PCM went into a reset mode and cleared all learned
>values
>
>Glenn
>

Considering the MIL gives a flash and there are no stored codes, I'd
bet the PCM is resetting. Another trip to the dealer that didn't even
bother checking for TSBs, even after repeat visits, is not what I'd
recommend.

I'd disconnect the knock sensor and drive it. If the symptoms stop,
then it was resetting because of the knock sensor. If the symptoms
remain, a scan tool (in the right hands) would be in order.

> On Mar 25, 9:03*am, philthy > wrote:

> find a shop that has a bore scope and have the flex plate checked for cracks/breakage and jambed into place i have one if you are near brighton michigan

I might try that, but how would a cracked flex plate cause the
symptoms to occur at almost the exact same time every time the car is
driven?

> On Mar 24, 8:19*pm, "maxpower" > wrote:


> 18-34-98 is a TSB that requires disconnecting *and taping the wire of the
> knock sensor for a symptom you are describing BUT this only occurs if the
> Module is resetting itself back to zero and all the learn values resets. A
> scan tool is required to determine if this is what is *happening.

Hmmm...so the scan tool can determine if the PCM is resetting back to
zero and erasing any stored codes? If so, shouldn't the dealer have
told me that the reason the PCM doesn't have any stored codes is
because it's been resetting itself?

> On Mar 25, 6:54*am, "maxpower" > wrote:

> No it doesn't. But the OP stated that it happens sometimes, a scanner would
> have determined that the PCM went into a reset mode and cleared all learned
> values

Well, you just answered my first question that I posted about 30
seconds ago. A scanner can tell if the PCM went into reset mode.

Now I wonder if the dealership knows this and sold me a PCM that I
really didn't need.

> On Mar 25, 1:27*pm, bllsht > wrote:


> I'd disconnect the knock sensor and drive it. If the symptoms stop,
> then it was resetting because of the knock sensor. If the symptoms
> remain, a scan tool (in the right hands) would be in order.

Sounds like a reasonable suggestion. Can anyone give any reasons why I
shouldn't disconnect the knock sensor?

On 25 Mar 2007 11:36:33 -0700, "powrwrap" > wrote:

>> On Mar 25, 6:54!m, "maxpower" > wrote:
>
>> No it doesn't. But the OP stated that it happens sometimes, a scanner would
>> have determined that the PCM went into a reset mode and cleared all learned
>> values
>
>Well, you just answered my first question that I posted about 30
>seconds ago. A scanner can tell if the PCM went into reset mode.

A good scanner can give the user the info. It's up to the user to
interpret that info.

>
>Now I wonder if the dealership knows this and sold me a PCM that I
>really didn't need.

If I remember correctly, you were still getting cam or crank sensor
faults before the PCM was replaced. You haven't mentioned any since it
was replaced. Could be you've had 2 different problems.


>

> On Mar 25, 4:20 pm, bllsht > wrote:

> If I remember correctly, you were still getting cam or crank sensor
> faults before the PCM was replaced. You haven't mentioned any since it
> was replaced. Could be you've had 2 different problems.


Yes, using the Co-Pilot device the stored codes were simultaneous cam
sensor AND crank sensors faults. Since I had already replaced them
they suspected the wiring between these sensors to the PCM or the PCM
itself. The wiring checked out OK, so that left the PCM as the most
likely source of the trouble.

I suppose it could be that I've developed another problem since the
PCM was replaced that is causing the PCM to reset itself. When the
dealership said there were no stored codes, I wonder if they checked
to see if the PCM was resetting and clearing them out. I guess I'll
call them tomorrow and ask about that and also the TSB.

"powrwrap" > wrote in message
ups.com...
> On Mar 24, 8:19pm, "maxpower" > wrote:


> 18-34-98 is a TSB that requires disconnecting and taping the wire of the
> knock sensor for a symptom you are describing BUT this only occurs if the
> Module is resetting itself back to zero and all the learn values resets. A
> scan tool is required to determine if this is what is happening.

Hmmm...so the scan tool can determine if the PCM is resetting back to
zero and erasing any stored codes? If so, shouldn't the dealer have
told me that the reason the PCM doesn't have any stored codes is
because it's been resetting itself?


Like it was already posted, a tool is only as good as the person using it,
but yes it can see that everything has been reset. disconnecting the knock
sensor if so equipped wont hurt, but not your problem. The TSB you are
referring to is a one time occurrence while driving, it WILL NOT cause
severe bucking or constantly surge. What you would experience if this was
the problem with a knock sensor would be a quick surge as the PCM reset
itself. and then run fine until a next start up.

Glenn

On Mar 25, 6:56 pm, "maxpower" > wrote:

> The TSB you are
> referring to is a one time occurrence while driving, it WILL NOT cause
> severe bucking or constantly surge. What you would experience if this was
> the problem with a knock sensor would be a quick surge as the PCM reset
> itself. and then run fine until a next start up.

This is exactly what happens. One sudden jerk, flash of the Service
Engine Light, then everything back to normal driving. Next day, same
thing, at about the same distance/time traveled.

In article
.com>,
"powrwrap" > wrote:

> On Mar 25, 6:56 pm, "maxpower" > wrote:
>
> > The TSB you are
> > referring to is a one time occurrence while driving, it WILL NOT cause
> > severe bucking or constantly surge. What you would experience if this was
> > the problem with a knock sensor would be a quick surge as the PCM reset
> > itself. and then run fine until a next start up.
>
> This is exactly what happens. One sudden jerk, flash of the Service
> Engine Light, then everything back to normal driving. Next day, same
> thing, at about the same distance/time traveled.

You could have disconnected the knock sensor in the same amount
of time it took to post.