Jordan S.

iTrader: (17)

Ok, I have a couple problems on two different cars that I think are both related.

My car, I wrecked it last year, went to the body shop to get fixed. When I get it back I notice my nitrous line is fried. One of the retards at the body shop grounded out my nitrous line to the positive on my battery. I'm not sure how long it was on there but it was long enough to discolor the stainless for about 3 foot and melt the nylon. Yeah pretty ******* long.

My problem is sometimes the car wont start. If I hop in turn the key and it turns over but won't start. It will act like it wants to start but it will backfire. I can get it to start by turning it off before it back fires and turning the key to start it again. After about three times it will just fire right up.

The SES is showing a Camshaft Position Sensor Low Voltage.



On my buddy's car, when he put his headers on he grounded the positive on the back of alternator. He grounded it out pretty good. It has had the same problem my car now. His car also has a SES Camshaft Position Sensor Low Voltage.

Ok, so his car being the guinea pig we put a new camshaft position sensor on it, still does the same thing.


I was thinking maybe it was the crank sensor it could have fried but there is no SES for the crank sensor.


I need some help so anything is appreciated, I'm no electrical genius so I could use any type of help. -Thanks!

gametech

iTrader: (1)

My best guess would be a PCM circuit was damaged.

MarcouxTA

Im with gametech, i think your pcm is NFG. do you have a scanner?? tech2??

Jordan S.

iTrader: (17)

No I don't have a scanner or tech II, it'd be nice if I did.


We bought a PCM for the 98', and thats what I originally thought the problem was. The one we got made the car run terrible so we put his original one back in. I think the one we got was bad so we sent it back. I'll look for another one to pick up.

Jordan S.

iTrader: (17)

Now, all my headlights stay on and my left turn signal is lit even though none of my turn signals are off. I just put new injectors in and noticed the lights seemed funny before I pulled it in the garage. Now when I started it back up my lights are funky.

One bright will be on full blast, the other bright will be barely lit, and the other two dim lights were barely lit.

I put a new camshaft position sensor in it. It started right up but sometimes it starts sometimes it doesn't. Who knows if when I started it was one of the times it just fires right up.

Can anyone here help?

Jordan S.

iTrader: (17)

I'm going to order a new PCM tomorrow, I think that is what the problem is but if anyone has any ideas I'd like to hear them.

vsellens

sounds like a ground problem.

Jordan S.

iTrader: (17)

I will run threw and check them all.

Jordan S.

iTrader: (17)

Ok. We replaced the PCM in the 1998 car. It still has the same problem. We took it to a friends shop who hooked his Mac Scanner up to it. His car throws the same code as mine.

Camshaft position sensor input low voltage is the code it throws.


This all began when he was grounded out the positive on the back of his alternator hard. My car came back from the body shop with a nitrous line that was almost melted from it sitting on the positive on the battery. Both our cars throw the same code and do the same thing.


Symptoms:

Upon starting the car, I turn the key on. I turn the key to start it. The car will turn over but it will not start. If I leave it turning over long enough you can hear the car begin to slightly backfire. If you give it gas it will back fire loud.


I've been doing as much research as I can. From what I can understand about the camshaft position sensors job is it tells the engine which side of the motor to send the spark to.

This makes sense to me, maybe it is sending spark to the wrong side of the motor and when enough fuel puddles up it backfires.

We replaced the camshaft and crankshaft position sensors though.

So... now I'm onto the wire. We looked at AllData at my freinds shop. The camshaft input wire is the brown and white one on the pigtail that plugs into the sensor.


I'm going to search on here to find the pin location on the PCM if there is one or try to find out where this wire leads.


I think it might lead to the wiring harness. Who knows, I'm just making guesses and I've missed everytime so far.

Somebody help come on, where are the electircal gurus on this board? Has nobody read about this problem in another thread so they dont know the answer?


I checked all the grounds visible. Does anyone have a diagram to every ground on the car? Or any diagrams to the camshaft position sensor and where that wire runs around to.

Jordan S.

iTrader: (17)

The code:

P0342 Camshaft Position Sensor Circuit Low Input


P0341
The ECM detects that the engine has started and is running, but receives less than 398 or more than 402 CMP pulses per 100 engine cycles in 800 of 1,000 engine cycles.

P0341
Ignition OFF, inspect the CMP sensor for correct installation.
⇒ If the CMP sensor is loose, inspect the sensor and the O-ring for damaged, replace as necessary.

Inspect the engine for the following conditions:
• Engine oil for debris

• Camshaft reluctor wheel for damage

• The timing chain, timing chain tensioner, and sprockets for wear or damage

⇒ If debris is found in the engine oil, inspect the internal engine components to determine the root cause. Repair or replace any worn or damaged components. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection .





Camshaft Reluctor Wheel
The camshaft reluctor wheel is part of the camshaft gear. The reluctor wheel contains a pattern of 2 narrow teeth, and 2 wide teeth around the circumference of the wheel. The falling or trailing edges of the 4 teeth are evenly spaced at 90 degrees apart. The engine control module (ECM) recognizes the narrow and wide tooth patterns to identify camshaft position, or which cylinder is in compression, and which is in exhaust. The ECM also uses the reluctor wheel information to determine the camshaft relative position to the crankshaft position.

Camshaft Position (CMP) Sensor
The camshaft position (CMP) sensor is a 3-wire sensor that provides a digital output signal. The wire circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, a low reference circuit between the CMP sensor and the ECM, and an output signal circuit from the CMP sensor to the ECM. The CMP sensor detects magnetic flux changes between the teeth and slots on the 4-tooth reluctor wheel. The CMP sensor provides a digital ON/OFF DC voltage of varying frequency, with 4 varying width output pulses, per each camshaft revolution. The frequency of the CMP sensor output signal depends on the speed of the camshaft. The ECM will recognize the narrow and wide tooth patterns to identify camshaft position, or which cylinder is in compression and which is in exhaust. The information is then used to determine the correct time and sequence for fuel injection and ignition spark events. The ECM also uses the CMP sensor output signal to determine the camshaft relative position to the crankshaft position.




I found this in another post. It is helpful. I beleive this is the code read out from alldata? Does anyone have a read out for the P0342? We could not remember the number earlier and did not look it up while at the computer in the shop.

Jordan S.

iTrader: (17)

After the car starts it runs great. Sometimes it starts up just fine, other times it does its old trick and takes its four try start.


I reset the computer today. When I put the old PCM back in I touched the battery cables together for a minute with the PCM unhooked. When I started it up I had the same old problem.

During the relearn period is there anything for the crankshaft or camshaft position relearn? I read it will not happen if a certain list of codes is pulled. One of them includes the one I have. I can't help but wonder what would happen if I deleted this code to see what would happen.


For sometime I had a problem with the tach not working on start up. I would start the car and the tach would not respond. Usually after about a minute it would bounce back up. Here lately it quit working all together.


The tach works in the 98 car. But when I rev it the speedo moves a few minutes.

Jordan S.

iTrader: (17)

Does anyone have any recommendations on checking the input signal wire? Is there I way I can test it with an voltage meter? Maybe I could get an resistance reading from the connector on the sensor to the pin on the computer?

finallygot1

iTrader: (4)

I have all the wiring diagrams, and I am having about the same problems you are, let me know if you still need the wiring. There are 3 pages of grounds alone

kkslds

iTrader: (59)

Wow thank god I didnt have this trouble. I did h/c to a buddies ta and the positive on the starter was touching the header. After that header got nice and hot the insulation caught on FIRE . Anyways luckily the insulation was all that was hurt. Also forgot to tighten the ground on the back of the head . It was ok though after it got tightened. I know a local guy whos a pretty knowledgeable on the wiring side. his specialty I'll see what he can come up with and i'll get back to you.

Jordan S.

iTrader: (17)

Hey that would be great man! Is there any way you can post them up. If not email them to me and I'll try to find a way to. I see alot of people have had this problem so I want to put some info up on here that might help others in the future.

My email is MaxxRacer7@aol.com or PM them, w/e works. Thanks!

Jordan S.

iTrader: (17)

Thanks for the tips. I think its time to start running grounds.

Jordan S.

iTrader: (17)

....... Nobody?

Hrlyrdr97

iTrader: (8)

Hey Jordan S. Just did a search and came up with this thread. Have been having the same problem for awhile now. Have found several people having the same problem but have not seen many fixes. Did you ever get yours fixed or are you still having same problem? I just pulled intake off and installed new cam sensor. Wanted to do anything else possible that I needed to before putting intake back on. Did you get info on grounds? Did it help? Let me know. Thanks in advance.

Jordan S.

iTrader: (17)

I got into my car and I had all sorts of problems in the harness. I sent the harness off for repair and had it done the easy way.

I am working on the 98' right now. It had no voltage at all at the pigtail. Tracing it to the PCM.

Jordan S.

iTrader: (17)

The 98 had a break in the 5v reference wire.