CAM Position Sensor Help

[BarryG]

Anybody know how this thing works. I get a code referencing the sensor. When it acts up it misses noticably sometimes worse than others. Sometimes it is really bad. Changed out the sensor and no better. I had already unhooked the Juice before I changed the sensor so it doesnt seem to have anything to do with that.

Anybody have any ideas on what to check next. The sensor looks like a magnetic sensor or something. Is there a tone ring it is sensing? Could it be messed up and if so how do you change it out. Any other ideas on it would be welcome. Does anybody know if the sensor is read through the pcm or the ecm? I am totally lost on this one. I dont want to just start throwing expensive parts at it nor do I want mr mechanic doing the same thing.

The only other codes I have I can explain and have had for quite sometime as in a couple years (grid heater circuit 2, lift pump voltage which isnt hooked up due to my rasp setup)

[Vaughn MacKenzie]

Follow the wire to the sensor & make sure it's not damaged or chafed anywhere. Also try electrical contact cleaner on the connector then add terminal paste to keep it clean & corrosion free.

[JLandry]

Barry,

What is the exact trouble code you're getting? What are the driveability symptoms?

Yes the Camshaft Position Sensor references a tone ring and the signal is an input to the ECM. The ECM then sends a crankshaft (not camshaft) angle reference signal (derived from the camshaft position sensor) to the PCM on a dedicated line. The PCM and ECM communicate back and forth together via the CCD (Chrysler Collision Data) bus.

Best regards,

John L.

[BarryG]

JL:
It shows itself as a miss. Sometimes it is just noticeable. Other times it is definitely a miss and a few times it is uh oh I hope this stops real soon because this is really freaking me out. It really seems to drive fine, when it is doing it the worse you can feel a bit of bucking if driving down the road. I have watched the tach when it acts up and it might bounce a bit but is very minimal.

The code itself now I cant remember the exact number but when I looked it up in my manual it said ckp sensor but my truck doesnt have one it has the cam sensor and mentions that in the manual. However when I get home I will recheck the codes and post them up for the exact numbers.

Doesnt seem to make a difference if the engine is hot or cold. I have driven for hours then it will do it and I have had it do it within 2 minutes of startup. It does seem to be getting worse both more frequently and more pronounced.

Vaughn:
I looked at the wire once but there was nothing obvious really just a quick once over. I will take a much closer look.

[FLynes]

When did Dodge change from the crankshaft position sensor to the camshaft position sensor? I ask this because I went to hoesli diesel's website and they list both sensors for 1998.5-2002 (Engine Position Sensor, crankshaft, pn 4921601 & Position Sensor, camshaft and/or crankshaft, pn 4921597).

So which one do you use? I've got a student with a 2001 5spd 2wd who is throwing a P0216 code, as well as a P0234, and I'm wondering if his ckp/cam sensor is bad, instead of the VP44...I read Gary's old post about whether the ckp/cam sensor can cause a P0216 code.

[Mishkaya]

Originally Posted by FLynes

When did Dodge change from the crankshaft position sensor to the camshaft position sensor? I ask this because I went to hoesli diesel's website and they list both sensors for 1998.5-2002 (Engine Position Sensor, crankshaft, pn 4921601 & Position Sensor, camshaft and/or crankshaft, pn 4921597).

So which one do you use? I've got a student with a 2001 5spd 2wd who is throwing a P0216 code, as well as a P0234, and I'm wondering if his ckp/cam sensor is bad, instead of the VP44...I read Gary's old post about whether the ckp/cam sensor can cause a P0216 code.

Don't know the exact answer, but my '01 only has the cam position sensor, and not the crank position sensor (early model '01, with rear drum brakes).
mishkaya

[BarryG]

Jlandry:
Here is a current list of codes that shows up

1693 dtc detected in companion module
0382 intake air heater relay #2 control circuit (this one has been there for over 2 years)
1690 fuel injection pump ckp sensor does not agree with ecm ckp sensor

obviously at this moment the 1690 is the pertinent one. However I could have sworn the last time I checked it showed 0336 ckp sensor performance

Since it now shows a 1690 I am more inclined to think vp44 issue than sensor. That would be just fantastic if that is it, cant wait to replace that again, number 4. They seem to last me right about 70k

However am still pretty positive that it showed a 0336 last time around. Possibly it did and replacing the sensor fixed that code.


FLynes
When I went to my local shop/friend to see what they knew about the sensor they were confused as well about the ckp/cps. Especially when I told them what my manual had said. They called dodge while I was there and spoke to whoever. Dodge told them that my truck did not in fact have a ckp just the cps. That it was the same sensor though. My manual also states that the cps will not set the mil but it did. The CKP is down by the starter and on my truck it is definitely not there. So I would suggest looking there first to see if it has a ckp. If it does not then it must have a cps. As far as what year it switched I do not know my guess would be 2000 or 2001 based on how the manual was written -confusing like it was an afterthought.

[FLynes]

Barry,

Yeah, I don't remember having a CKP sensor either...I replaced the innards on my starter several months ago and did not see anything around the starter.

I told my student to bump start the truck to see if he could hear the LP....he heard it, the next logical step is to replace the fuel filter and I'm thinking that the CPS should be next, with the VP44 as his last resort. He did tell me that he took the fuel filter cap off to look at the filter, when he first bought the truck, so I'm wondering if he might have some air trapped in the lines...I would think that it would have worked itself out by now though.

So is the general concensus that the CPS can/will cause a P0216?

[JLandry]

Originally Posted by BarryG

1690 fuel injection pump ckp sensor does not agree with ecm ckp sensor

Barry,

The P1690 trouble code seems to be caused by a timing signal communication problem (or disagreement) between the ECM and VP44. This would certainly explain the intermittent miss you've been experiencing.

I've attached both the old and new (supplement) P1690 pages from the Dodge Diagnostic Procedures Manual.

The old P1690 pages tell you to first check for AC noise on the ECM power supply circuit, then check connectors and wiring between the ECM and VP44. If all checks come out normal, you're supposed to replace the ECM. The new (supplement) P1690 pages don't mention checking for AC noise and.

It seems to me that even though they don't mention it, the problem could be caused by the VP44's internal computer.

Originally Posted by BarryG

However am still pretty positive that it showed a 0336 last time around. Possibly it did and replacing the sensor fixed that code.

What's interesting is I'm not finding a separate P0336 page in the Diagnostic Procedures manual... just references to it in other trouble code pages (P0216 and P1690).

Best regards,

John L.

[JLandry]

Originally Posted by FLynes

So is the general concensus that the CPS can/will cause a P0216?

The Dodge diagnostic procedures don't seem to support that conclusion... but the procedures aren't perfect.

I've attached the diagnostic pages for P0216 trouble code.

John L.

[FLynes]

John,

Thanks for the page, I'll pass it along to my student.

[FLynes]

Funny thing about looking at this thread....three days after my post, the Bank 1 CPS on our BMW 740iL went out this weekend, according to the on-board computer, but you wouldn't have known it from the way it drove. Apparently I have 4 of these SOBs, two on each side, one for intake and one for exhaust. Got a new one for $94 on the way and replacing it myself....the stealership wanted $202 for the part and another $116 to install and clear the code.

[Uncle Dim]

I've read through I don't know how many posts about the crank position sensor. The day I sold my father my 00 2500 the tach started acting up and the CIL came on. Cycled the key and got the P1693. It came and went for months. While we were replacing the vacuum pump seal we took care of the CPS. Didn't help. Late we checked and cleaned all the CPU connections and the grounds. Didn't help. Finally I let him take my 04.5 while I look into the issue. He the codes read and it pull P0336, P1689 and P1690. Seems to me that the last 2 are communication errors related to the 3 computer not agreeing. The P0336 is straight forward enough. Looks like to even check the connection on the CPK you need to remove the starter. I guess the best option to replace the CPK. Dealer want $98.!

Has anyone had any luck checking the connection without removing the starter? I would like to do that before dropping another $50 on a truck I don't own anymore.

[Uncle Dim]

Replaced the CPK sensor and the codes are gone. I'll keep my finger crossed that it is gone for good.