[Braetcmmc]

Hello to all:

I own a 2012 Traverse with 114,000kms on it.
Recently the Eng light came on and it reveals two separate OBD II codes.

P0017 - Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)
https://www.obd-codes.com/p0017

P0420 - Catalyst System Efficiency Below Threshold
https://www.obd-codes.com/p0420

So I have read through much of the info in the above links plus other forum discussions. So based on my research these are my questions:

1. Has anyone had these two codes come in together at the same time?
2. Is the Crank and Cam sensors accessible(external) to inspect by me? Or does a mechanic have to do it (internal)?
3. Could P0017 be set off by just a loose or shorted wire? (electrical?)
   
4. Could this be related the Technical Safety Bulletin 12-06-01-009E that is related to the timing chain replacement kit? ((There is mention of the chain stretching causing the two sensors Crk and Cam to go out of time))
5. Has anyone done the timing chain kit replacement themselves? and are there any good resources online: I.e. videos, forums etc. that you may have used to perform this?
6. Finally, if it is the timing chain, I think possibly the other code may go away because the engine will run efficiently (neither advanced nor retarded). Please share your option here?
   

TSB link is here: www.autocodes.com/uploads/gmc/12-06-01-009E.pdf


Thanks

 

[rbarrios]

to me-- that P0017 code means the chains on this engine.

I believe you can try an oil change and see what happens.


But many times- owners do not check oil level on this engine- and it leads to accelerated wear on that chain and possibly sludge.
you are nearing 71,000 miles.... young engine.

 

[rbarrios]

lots of post on chains.
Try youtube on the chains.

some have done them themselves.

engine has to be dropped for this.

though have seen video of engine in place--- but all panels- bumper- etc had to be removed to properly access the engine cover for the chains

 

[Braetcmmc]

to me-- that P0017 code means the chains on this engine.

I believe you can try an oil change and see what happens.


But many times- owners do not check oil level on this engine- and it leads to accelerated wear on that chain and possibly sludge.
you are nearing 71,000 miles.... young engine.

-----

Thanks.
I did change the oil 400kms ago.
I change it faithfully every 8-10,000kms, use Mobil 1 synthetic since new. Mobil 1 is good for 15,000miles

 

[Braetcmmc]

lots of post on chains.
Try youtube on the chains.

some have done them themselves.

engine has to be dropped for this.

though have seen video of engine in place--- but all panels- bumper- etc had to be removed to properly access the engine cover for the chains

----

What do you engine dropped? Do you mean separated from the tranny?

 

[rbarrios]

the vehicle is raised--- all connections undone--
and the engine cradle is lowered...... the engine/trans/front suspension comes down as a whole unit.
note the cleaning they do to the area of the chains....etc..
lots of this work would be difficult- if it sat in engine.


Enclave (same as Traverse)

similar.

 

[greentraverse]

Interesting video. Never saw a torque wrench.

 

[Braetcmmc]

Thanks for the video's of the engine dropping.
Strange as I would never have thought about doing this.
After viewing these, one video lead to another and I found the Cloyes install without removing the engine and found another video with some warnings, both were very helpful.

Also contacted my dealer and explained the problem to him.
He is doubtful it is the chains because of the mileage and the fact that I switched from the factory Dexos oil immediately to Mobil 1 and changed it faithfully.
Also he asked if the engine had a rattle upon start up in which it does not. Other than the SEL coming on the vehicle engine performance has not changed.
I drove my daughter back to university yesterday. So before we left, I scanned the codes, P0017, B2aaa appeared, cleared them and then drove away. 2.5 hrs later, arrive at university and NO SEL.... Good.... shut down engine, unload, etc. kiss goodbye, etc.

Restart engine. No SEL. put in gear within 60secs SEL re-appears. Drive for a bit, gas up, rescan/clear codes. Then we're good all the way back home NO SEL.
At home shutdown, restart, again put in gear, within 60secs codes reappear.

So it does not produce the code while driving, but as soon as the engine is shut down and re-started, it picks the code back up.

I'm going to examine the wiring harness tomorrow and check for faulty wiring first then look into the sensors next.
I think it may be either: wiring, sensor/s and ultimately timing chain but hope not as the extended warranty is not covering it.

I think I asked previously, are the sensors exposed externally?
Can these be changed without a tear down?

 

[whipster]

Yes, you can change the sensors without removing the engine.

 

[Braetcmmc]

Dealer diagnostic WRT Code P0017

Here is an update from the dealer WRT the P0017 code:

The following is what I did before taking it to the dealer:

Hi dealership:

I just wanted to give you an update on what I have done so far to try and figure out the code P0017 that is listed below. I know we talked earlier and you seemed to think the stretched timing chain was only on earlier models Pre-2012.
I did some research, ran a few tests and changed some parts. The following is what I performed:
Removed the crank shaft sensor from the back side of the engine block, cleaned it, inspected the port hole, nothing abnormal, re-installed it. I cleared the codes and drove it for a day and then the code P0017 came back on after restarting the engine next day. So I am not sure if the sensor is working as I don't know how to test it?
Removed the plastic engine cover, still off, and I replaced the #7, Bank 1 right (CMP) actuator sensor (Intake).(see illustration below) Reset codes, run for a day then after engine restart, the code P0017 reappears.
Removed the same sensor #7 Bank 1 right (CMP) actuator sensor (Intake) that I just installed and replaced it with the original. Then installed the new actautor in the #5 position Bank 1 right (CMP) actuator sensor (Exhaust) "Same P/N". Cleared codes, Run for another day and after restarting engine code re-appears.
I did not investigate Bank 1 positions 6 and 8 as illustrated below nor did I check Bank 2

There is a list of symptoms here that the engine is not replicating, I hope it is not the timing chain and only something electrical.
Symptoms of a P0017 will or may include:
Malfunction Indicator Lamp (MIL) illumination - YES
The engine may run but with reduced performance - NO - performs as new
The engine may crank but not start - NO issues here either
The engine may exhibit a rattle near the harmonic balancer indicating the tone ring is damaged - No rattle
The engine may start and run, but poorly _ NO performs excellent

Dealer Technician diagnostic:
"Check cause of engine light on - Tech Story - scan tested found p0017 crankshaft position - Exhaust camshaft position correlation Bank?
Code resets if cleared.
Checked cam shaft data - all positions are reading 0 degree because of set code - if actuator was bad the degree would vary.
Bank 1 timing chain must have jumped - needs new timing chains.
Completed by: Techs name"

So my question to the forum is:
Do you agree with the tech's assumption? if the actuator is reading 0 degrees then the chain must have jumped a tooth?
The engine has 3 chains, I believe if one chain jumped then the other two should be in disagreement with the single chain that jumped?
??

 

[Braetcmmc]

OBD II Code P0017 Timing Chain Problem resolved (it was cam phasor)

UPDATE: RESOLVED OBD II Codes P0017
OBD II Codes P0017 and P0420 Timing Chain and Cat effic'y Post closed, problem resolved

Hello All:

I wanted to send an update on my problem regarding the ODB II code P0017 that my traverse was displaying.
I got a second option from my own mechanic; see previous post for Dealer diagnostic WRT Code P0017.
After I explained all the symptoms to my mechanic which I detailed in all the posts above, these are the results of his findings:

P0017 - Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)
https://www.obd-codes.com/p0017

The chains have some wear but nothing abnormal
The exhaust cam phasor on Bank 1 was abnormally worn on the gears.
The 3 other cam phasors have wear but not as much as Bank 1 exhaust.
If the chain jumped a tooth or if it was the timing chain worn out, both intake and exhaust sensors should have triggered, (Should have seen both of these codes P0016 & P0017)
This would go for Bank 2 as well, if it truly is the timing chains wearing or stretching then both P0018 & P0019 should triggered.
He said you cannot have one code without the other code triggering the MIL. Therefore the problem lies between the individual cam phasor and the crank sensor

So bottom line for my P0017 code was: worn exhaust cam phasor on bank 1 due to poor Harding of the metal or metallurgy chosen for original OEM parts.
As I indicated above, I used Mobile 1 Synthetic since new, 120,000kms on the clock, all components where clean and well lubricated. Also while P0017 code triggered no engine performance issues were detected.
So while the engine was apart I had my mechanic replace all the components: new timing chain kit including all idler sprockets and guides and replace all 4 cam phasors with new ones.
After repair was completed, codes all reset automatically.

I asked for the parts back and created a diagram below of my findings. I also have a photo, credit from Cloyes Gear & Products, to illustrate my argument that I do not believe the chain could ever jump a tooth because the tensioner's and guides create such a reversed arc that it seems impossible. Check it out, I'm not going to entertain a discussion, this is just my option.

Cost to repair $3,200 CAD taxes included
Included all replacement fluids, oil, coolant, & PS fluid, complete timing chain kit, 4 cam phasors and 2 complete Amsoil changes (10qts +2 filters) I plan to change the oil after 5,000kms.

Thanks for all the advice as it was very helpful.
I am also very glad I got a second option.
CB

 

[greentraverse]

Just to be clear:

Your first pic says "Looking straight at engine from left side engine compartment." (Emphasis added.) To me, this means you're looking at the engine from the drivers (left side) side of the engine compartment.

I suspect that's not what you meant. I suspect you meant it's on the left side of the engine compartment when looking at the engine from the front of the car; in other words, the PASSENGER side of the engine. The front of the engine where the timing chains are located is on the passenger side of the car.

 

[Braetcmmc]

Just to be clear:

Your first pic says "Looking straight at engine from left side engine compartment." (Emphasis added.) To me, this means you're looking at the engine from the drivers (left side) side of the engine compartment.

I suspect that's not what you meant. I suspect you meant it's on the left side of the engine compartment when looking at the engine from the front of the car; in other words, the PASSENGER side of the engine. The front of the engine where the timing chains are located is on the passenger side of the car.

Sorry, when I work on the truck I reference from the front looking at the vehicle so yes it is on the passenger side.


The main point was by viewing the engine straight on as though you were standing on the passenger side looking directly at the timing gear. I just laid it all out on plywood and tried my best to replicate it.

CB
:smile: