: Cam Position Sensor DTC and Door Locks



SFBayV
04-12-10, 08:29 PM
It's been a while since I've posted, but I've got an odd problem with the V.

For the past few months or so the SES light has been coming on and after checking the DTC, it showed as being for low voltage output from the camshaft position sensor. The result is a difficult starting condition. Basically, the starter has to crank for several seconds before the engine actually starts. This problem is intermittent however, as the light will go out by itself on occasion and the car will start normally. This has occurred off and on over the last few months. I haven't had the time to diagnose the problem yet.

The odd part is that whenever the SES light comes on, the car is difficult to start as mentioned, but the automatic door locks stop functioning at the exact same time. Meaning that if I'm driving the car and the driver's door lock won't go down, it's a sure bet the SES will come on soon or the car won't start on the next try. Likewise, if the SES is on and the car is hard to start, the driver's door lock won't lock or unlock automatically. Conversely, if the automatic door lock works, the SES is out and the car starts fine. Again, this all occurs at the same time back and forth.

I'm assuming that the automatic door locks are controlled by the BCM, so where would there be a connection with engine management? I don't believe that these are separate issues, but rather that there may be crossed wires or poor connections somewhere.

My question to the forum is, if anyone has any ideas as to where to look. Thanks to all.

Cory

SkullV
04-12-10, 08:46 PM
Wow..I have the same code...and my door locks were having issues last week...this gives me hope!

Wads56
04-12-10, 09:01 PM
The code and door locks are tied together. Fix the code and the locks will work.

SFBayV
04-13-10, 12:39 AM
So it could be a few different things. The car was in for service at the dealer a while back and the service department pinched some wires when they reinstalled the bell housing / transmission. I was getting ridiculously high transmission oil temps as a result. I don't know how well or how permanent the repair was done, so I'm hoping it's the problem. I don't to take the intake off and change the sensor if I don't have to, so I'd much rather find another solution.

SkullV, if you find a solution to your problem before I find mine, plese let us know what it is.

SkullV
04-15-10, 05:54 PM
The dealer has my car and has ordered a cam position sensor and intake manifold gaskets. The tech said they him to pull the sensor and test it before they go any further into the repair. I'll keep you posted.

SFBayV
04-16-10, 01:51 AM
Wow. I'd be very interested in the outcome. Did the dealer say if there was any possible correlation with the automatic door locks?

SkullV
04-16-10, 01:37 PM
I forgot to ask about the door locks again, but they called and the sensor was not the issue (Just like Ewill said it wouldn't be) and they have gone ahead with replacing the cam bolts and fixing everything associated with the problem. I should be back on the road by Tuesday!

SFBayV
06-14-10, 05:07 PM
Well, for about a month, the car worked fine. The CES light went out and the car has been starting like normal and the auto door locks have been functioning as they were supposed to. I couldn't figure out were the trouble was. Then about 3 weeks ago, the I washed the car and all the same symptoms returned. Now that the car is completely dried out (thanks to some warm weather), it's back to functioning as normal.

Basically, the trouble is electrical and not mechanical. It isn't the camshaft position sensor and it certainly isn't one involving loose cam bolts. It dawned on me that the problem didn't start until after the dealer service department replaced both headlight assemblies. So it stands to reason that since they were in the general vicinity of the ecu, they didn't reassemble the front correctly and as a result a little moisture is getting into the electronics. I'll be digging in to this area when I have a chance and hopefully I'll be able to resolve this once and for all.

-C

rdjiv
06-15-10, 09:10 PM
I had some intermittent startup issues similar to what you described but not exactly. Sometimes the startup would take several cranks more than usual, sometimes it would just die in the middle of startup. Once, while going down the road, the tach stopped working completely but, weirdly, the engine still continued to run. I got a CEL from that experience. Took it in to dealer who followed the code (crank position sensor) and visually saw some wires touching some metal heat shielding, probably causing an intermittent short. Once properly electrically isolated, the problem seemed to be fixed.

Although, I've experienced a rough startup the other day so maybe the insulation has unfixed itself.

You're probably on the right track with the thought of electrical problem vice mechanical.

SFBayV
12-01-11, 06:12 PM
Problem solved finally. It turns out that the CPS was bad all along. I still don't know how that relates to the operation of the auto door locks, but everything is perfect now that a new CPS is in.

-C