P0021 Error

[srfrdrew]

Well, got my new Autel MaxiDAS 708DS scanner and sure enough it caught something my Generic ODBII scanner did not..

 

"P0021 - A Camshaft Position TIming Over-Advanced or System Performance Bank 2"

 

I have a 2004 Cayenne S with 127K on the ODO

 

There was no CEL, I have gone ahead and cleared the code....

 

No other codes present and clear.

 

I have been complaining about idle drop at stop as well as vibration durning the idle dip (I know the vibration due to idle dip is most likely due to engine mounts but not sure if P0021 plays any role here)

[JFP in PA]

Well, got my new Autel MaxiDAS 708DS scanner and sure enough it caught something my Generic ODBII scanner did not..

 

"P0021 - A Camshaft Position TIming Over-Advanced or System Performance Bank 2"

 

I have a 2004 Cayenne S with 127K on the ODO

 

There was no CEL, I have gone ahead and cleared the code....

 

No other codes present and clear.

 

I have been complaining about idle drop at stop as well as vibration durning the idle dip (I know the vibration due to idle dip is most likely due to engine mounts but not sure if P0021 plays any role here)

 

If the P0021 was real, you should have been able to see the cam deviation values as being well out of whack at the same time.

[srfrdrew]

Hey JFP,

 

Thanks for the input, I'm still bit of a shady tree mechanic....

 

Not sure if you are saying I should be seeing other "Codes" along with this one if this P0021 code is legit?

 

Should I be looking at live data regarding the cam deviations and what are they in numerical value?

 

Just looking around at others saying Vario-Actuator and/or cam phaser to be replaced.

 

Also, dealerships say it's a common code that is usually cleared and if it pops back up look at into further. They also have commented that P0021 is very common on the V8 engines, and from experience is due to a very slight extension in the timing chain and the sensor tolerance is very low.

 

I've actually heard this from my local Porsche Master tech, that the chains "stretch" and that could be partly attibuted to the idle dip/idle issue

 

Poor idle is indeed attributed to this code as well

Edited January 28, 2015 by srfrdrew

[JFP in PA]

Hey JFP,

 

Thanks for the input, I'm still bit of a shady tree mechanic....

 

Not sure if you are saying I should be seeing other "Codes" along with this one if this P0021 code is legit?

 

Should I be looking at live data regarding the cam deviations and what are they in numerical value?

 

Just looking around at others saying Vario-Actuator and/or cam phaser to be replaced.

 

Also, dealerships say it's a common code that is usually cleared and if it pops back up look at into further. They also have commented that P0021 is very common on the V8 engines, and from experience is due to a very slight extension in the timing chain and the sensor tolerance is very low.

 

I've actually heard this from my local Porsche Master tech, that the chains "stretch" and that could be partly attibuted to the idle dip/idle issue

 

Poor idle is indeed attributed to this code as well

 You should be looking at the cam deviation values (real time data) and they should be in normal spec range (+/- 6 degrees); if the VarioCam unit is acting up, the values should be well outside that range.

[srfrdrew]

Hi JFP,

 

OK, I have recorded about 10 minutes of data off the DME module which I believe is the area we are concerned with.

 

What should I be looking at?  I'm not sure if see a  "CAM" sub section within the DME listing.

 

Also, since I'm here... What other readings should I look at and expected values?  I was told to look at fuel trim regarding the idle dip coming to a stop.  Do you have expected values for that?

[JFP in PA]

Hi JFP,

 

OK, I have recorded about 10 minutes of data off the DME module which I believe is the area we are concerned with.

 

What should I be looking at?  I'm not sure if see a  "CAM" sub section within the DME listing.

 

Also, since I'm here... What other readings should I look at and expected values?  I was told to look at fuel trim regarding the idle dip coming to a stop.  Do you have expected values for that?

 

The critical item is camshaft deviation values, which are how far the cams are off the ideal value; on a Durametric system, they would look like this:

 

 

Porsche uses some unusual terminology on fuel trims; RKAT is the adaptation value near idle.  FRA is the adaptation value under load and further divided into FRAU (lower load range ) and FRAO (higher load range) ranges.

The RKAT values near idle are used to change the length of the injector pulse to account for deviations from ideality (ie intake leaks) to maintain the proper O2 sensor reading. The RKAT value is an additive factor and can deviate by +/- 4.5%. The FRA value is a multiplicative factor and can deviate by 1.32 to 0.70. The positive values or values greater than 1 increase the injector pulse length to account for a lean mixture, and negative values and values less than 1 are to compensate for a rich mixture.

 

[srfrdrew]

Hi JFP, so I have some data.. Not sure if I'm reading it correctly or if the scanner is reading it correclty

 

Camshaft Actual Angle

Bank 1 = 0 to 4 (and values in between)

Bank 2 = 0 to 4 (and values in between)

 

Camshaft Specified Angle

Bank 1 = 0

Bank 2 = 0

 

Camshaft Deviation

Bank 1 = stays in the 1's

Bank 2 = rises to the 90's and flatlines at 90

 

RKAT

Bank 1 = 0 to 1 to flatline 0's

Bank 2 = flatline 0's

 

FRAO

Bank 1 = 0 to 1 to 0

Bank 2 = -0 to -3  -0 to -2  -0 to -1

 

FRAU

Bank 1 = 0 to -1 to 0 to -2 to flatline 0

Bank 2 = flatline 0

[JFP in PA]

^{Based upon the excessive deviation on the bank 2 cam, I would say that the P0021 code is real.  What concerns me is the value as your engine would not run with a cam deviation of 90 degrees.}

[srfrdrew]

Hi JFP, i'm going to run these test again but just specific to the values below.  Before I was recording the whole DME, maybe was too much for scanner to handle

 

The Pig is certainly running (fairly good) albeit the idle dip and vibration when coming to a stop, other than that it seems to be running ok.

 

I'll post updated recordings shortly

 

Camshaft Actual Angle

Bank 1

Bank 2

 

Camshaft Specified Angle

Bank 1

Bank 2

 

Camshaft Deviation

Bank 1

Bank 2

Edited January 30, 2015 by srfrdrew

[sportplus997]

Sounds like a sticking camshaft actuator for sure...you should see B1 or B2 actual value sticking as you powerbrake the truck...to be honest with that mileage wouldn't hurt to change both along w valve cover gaskets

[royxaxa]

I had similar issue before with bank 1 P0016 and replaced the chain and lots of other stuff. 

search on 6speed. I had some write up there under zzzx. hope that helps.

good luck

[rpcc]

Here's the screenshots of the P0021 code and the actual cam deviation values - bank 1 is at 5 and bank 2 is at 1.

 

this is a 2004s with 78k miles - 

 

I've had the car for 2 years now and this one keeps coming back - changed the oil a couple of times and ran a can of cleaner through it.  

 

Any recommendations on the next steps to resolve this - I'm thinking for time and money involved it it maybe just live with it.  If it's some 5k chain replacement - car will be someone else's proud new owner.

[JFP in PA]

Here's the screenshots of the P0021 code and the actual cam deviation values - bank 1 is at 5 and bank 2 is at 1.

 

this is a 2004s with 78k miles - 

 

I've had the car for 2 years now and this one keeps coming back - changed the oil a couple of times and ran a can of cleaner through it.  

 

Any recommendations on the next steps to resolve this - I'm thinking for time and money involved it it maybe just live with it.  If it's some 5k chain replacement - car will be someone else's proud new owner.

 

Neither cam is currently out of spec, and the code is not currently active: 

 

P0021 Adjustment of Inlet Camshaft in relation to Crankshaft, Bank 2

– Signal Implausible Possible cause of fault

- Dirt in oil circuit

- Sealing strips on inlet camshaft adjuster faulty

- Oil pressure too low

- Mechanical fault in inlet camshaft adjuster

- Magnetic hydraulic valve faulty

 

 

Besides the above or dirt in the oil, an intermittent cam position sensor problem on bank 2, which should not trigger until the cams go +/- 10 degrees.

[rpcc]

Thanks JFP - I will have these checked out.

 

At times this car is my personal road to Tuva.

[oatmealadam]

I had similar issue before with bank 1 P0016 and replaced the chain and lots of other stuff. 

search on 6speed. I had some write up there under zzzx. hope that helps.

good luck

What exactly did you finally do to fix the issue?

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