Code P 0335

2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
replacing the crank shaft position sensor there was no improvement. The
mechanic tried a different electronic ignition module. Still no improvement.
He got another computer, had it "flashed", installed it and still no change.
Where do we go from here?

Thanks in advance. Any advice is welcome

On 11/25/10 8:23 AM, Grandma wrote:
> 2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
> suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
> replacing the crank shaft position sensor there was no improvement. The
> mechanic tried a different electronic ignition module. Still no
> improvement.
> He got another computer, had it "flashed", installed it and still no
> change.
> Where do we go from here?
>
> Thanks in advance. Any advice is welcome

Look here for some possibilities:

http://www.obd-codes.com/p0335

Grandma > wrote:
>2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
>suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
>replacing the crank shaft position sensor there was no improvement. The
>mechanic tried a different electronic ignition module. Still no improvement.
>He got another computer, had it "flashed", installed it and still no change.
>Where do we go from here?

Tell your mechanic to get a real analyzer and start looking at the waveform
coming off the sensor rather than just thrashing around replacing things
without doing any real diagnosis.

If you watch the actual signals you may find that the poor signal coming
off the sensor which produces the P0335 is a _symptom_ of the engine running
rough rather than the cause.

On the other hand, you may see ignition noise is getting into the sensor
wiring due to a bad ground. Without actually seeing the signal coming off
the sensor you won't know.

I'd definitely check all related ground points and make sure the block
ground cable is clean and tight of course.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 11/25/2010 10:23 AM, Grandma wrote:
> 2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
> suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
> replacing the crank shaft position sensor there was no improvement. The
> mechanic tried a different electronic ignition module. Still no
> improvement.
> He got another computer, had it "flashed", installed it and still no
> change.
> Where do we go from here?
>
> Thanks in advance. Any advice is welcome

Check TSB 02-06-04-059

Steve Austin wrote:
> On 11/25/2010 10:23 AM, Grandma wrote:
>> 2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
>> suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
>> replacing the crank shaft position sensor there was no improvement. The
>> mechanic tried a different electronic ignition module. Still no
>> improvement.
>> He got another computer, had it "flashed", installed it and still no
>> change.
>> Where do we go from here?
>>
>> Thanks in advance. Any advice is welcome
>
> Check TSB 02-06-04-059


Document ID: 1212710 #02-06-04-059: Engine Runs Rough, Service Engine
Soon Light On, DTC P0300 or P0335 Set (Shim Crankshaft Sensor) - (Dec
16, 2002)

Subject:Engine Runs Rough, Service Engine Soon Light On, DTC's P0300 or
P0335 Set (Shim Crankshaft Sensor)
Models:2002-03 Chevrolet Astro, Blazer, Express, Silverado and S-10
Truck Models

2002-03 GMC Jimmy, Safari, Savana, Sierra and Sonoma Truck Models
with 4.3L V-6 Engine (VINs W, X - RPOs L35, LU3)

Condition
Some owners may comment on a rough running condition or a Service Engine
Soon (SES) light being illuminated. Upon investigation, the technician
may find a DTC code P0300 or P0335.


Cause
The crankshaft sensor may be contacting the reluctor wheel.


Correction
Remove the crankshaft sensor. Refer to the Crankshaft Position Sensor
Replacement procedure in the Engine Controls-4.3L sub-section of the
Service Manual. After removing the sensor, inspect the end of it for
witness marks that would indicate contact with the crankshaft. If
contact with the reluctor ring is indicated, then inspect the front
cover for cracking or other signs of alignment concerns. If the
inspection indicates that the cover is causing mis-alignments, replace
the cover. If replacing the cover, then the 0.5mm shim is not needed.

If the inspection of the front cover indicates that the cover is not the
cause of mis-alignments, then the sensor should be shimmed. Add one shim
between the sensor and the front cover. If the concern still exists,
then add the second shim. Unless the sensor has been rubbed through the
casing or deformed by contact with the crankshaft, it should not be
replaced.

In either case, the crankshaft relearn procedure should be performed
after any repairs.


Parts Information

Part Number: 12565102
Description: Shim, 0.5mm thick
Qty: 1-2


Sensor Crankshaft Position: as req'd
12562910

On 11/25/2010 08:58 AM, Scott Dorsey wrote:
> > wrote:
>> 2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
>> suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
>> replacing the crank shaft position sensor there was no improvement. The
>> mechanic tried a different electronic ignition module. Still no improvement.
>> He got another computer, had it "flashed", installed it and still no change.
>> Where do we go from here?
>
> Tell your mechanic to get a real analyzer and start looking at the waveform
> coming off the sensor rather than just thrashing around replacing things
> without doing any real diagnosis.

indeed.


>
> If you watch the actual signals you may find that the poor signal coming
> off the sensor which produces the P0335 is a _symptom_ of the engine running
> rough rather than the cause.
>
> On the other hand, you may see ignition noise is getting into the sensor
> wiring due to a bad ground. Without actually seeing the signal coming off
> the sensor you won't know.
>
> I'd definitely check all related ground points and make sure the block
> ground cable is clean and tight of course.
> --scott


--
nomina rutrum rutrum

On 11/26/2010 10:13 AM, Steve W. wrote:
> Steve Austin wrote:
>> On 11/25/2010 10:23 AM, Grandma wrote:
>>> 2004 S10 Blazer 4.3L. Engine idles rough and when shifting the tach will
>>> suddenly jump to around 4000 RPM. The scanner retrieved code P0335. After
>>> replacing the crank shaft position sensor there was no improvement. The
>>> mechanic tried a different electronic ignition module. Still no
>>> improvement.
>>> He got another computer, had it "flashed", installed it and still no
>>> change.
>>> Where do we go from here?
>>>
>>> Thanks in advance. Any advice is welcome
>>
>> Check TSB 02-06-04-059
>
>
> Document ID: 1212710 #02-06-04-059: Engine Runs Rough, Service Engine
> Soon Light On, DTC P0300 or P0335 Set (Shim Crankshaft Sensor) - (Dec
> 16, 2002)
>
> Subject:Engine Runs Rough, Service Engine Soon Light On, DTC's P0300 or
> P0335 Set (Shim Crankshaft Sensor)
> Models:2002-03 Chevrolet Astro, Blazer, Express, Silverado and S-10
> Truck Models
>
> 2002-03 GMC Jimmy, Safari, Savana, Sierra and Sonoma Truck Models
> with 4.3L V-6 Engine (VINs W, X - RPOs L35, LU3)
>
> Condition
> Some owners may comment on a rough running condition or a Service Engine
> Soon (SES) light being illuminated. Upon investigation, the technician
> may find a DTC code P0300 or P0335.
>
>
> Cause
> The crankshaft sensor may be contacting the reluctor wheel.
>
>
> Correction
> Remove the crankshaft sensor. Refer to the Crankshaft Position Sensor
> Replacement procedure in the Engine Controls-4.3L sub-section of the
> Service Manual. After removing the sensor, inspect the end of it for
> witness marks that would indicate contact with the crankshaft. If
> contact with the reluctor ring is indicated, then inspect the front
> cover for cracking or other signs of alignment concerns. If the
> inspection indicates that the cover is causing mis-alignments, replace
> the cover. If replacing the cover, then the 0.5mm shim is not needed.
>
> If the inspection of the front cover indicates that the cover is not the
> cause of mis-alignments, then the sensor should be shimmed. Add one shim
> between the sensor and the front cover. If the concern still exists,
> then add the second shim. Unless the sensor has been rubbed through the
> casing or deformed by contact with the crankshaft, it should not be
> replaced.
>
> In either case, the crankshaft relearn procedure should be performed
> after any repairs.
>
>
> Parts Information
>
> Part Number: 12565102
> Description: Shim, 0.5mm thick
> Qty: 1-2
>
>
> Sensor Crankshaft Position: as req'd
> 12562910

good post.

to the o.p., when you have a tech that "replaces stuff", especially the
engine computer which is /highly/ unlikely to experience a fault like
this, you need to take your business to someone that actually knows what
they're doing. failure to look up tsb's, failure to understand why a
sensor code would return after sensor replacement, both are fundamental
problems that are costing you money.

to other techs - this is the problem with "black box" learning.
replacing the box only gets you so far. understanding what the box does
gets you much further. if you know how the sensor works, and how its
output relies on its interaction with its input, you can fix the problem
first time. and in this case, without having to replace anything.


--
nomina rutrum rutrum