Cam/Crankshaft Position Sensor

[wjkov]

2001 Lanos died while driving. I have isolated problem to likely being the crankshaft position sensor (or a short in the wiring somewhere). With this, does anyone have or where I can get the technical specs for "normal" resistence across this sensor? I would also like to check the camshaft sensor. Thanks.
(PS Just found the site, and looks like some real nice people here)

[daewoomofo]

jsut wonderin how did you marrow it down to the cam sensor?

[Trey05Woo]

Looool with all the timing belt horror victims just too hard not to ask lol. But yea the timing belt did not explode? And Im guessing you have no spark?

anyways I can surely provide you with all the electrical values and diagnosis its what I specialize in and will be glad to chip in. But get comfy cuz its going to be a lengthy post and first I would check for dtc's and if any are found start from there...

First you shouldnt be too worried about checking the resistance of the sensor more if it is sending a signal. Second camshaft sensor on these vehicles are used only to time injector pulsations, the vehicle will not stall or fail to start if the sensor goes bad, rather the ecm will switch to a preset mode and fire injectors accordingly and set a trouble code.

HOWEVER the cmp and ckp share the same ground and if the cmp were to short to ground and cause an open in the circuit then the vehicle would not start due to crank sensor loss of ground, and this usually does not set a code, and there is a bulletin which corrects this issue by installing a fuse inline of the cmp. Which brings me to the crank sensor which provides the ecm with crank position and speed. If this signal is not present the computer will not know when to fire the coil, and thus produce a no spark aka no start condition.

checking the sensor

The easiest way to check the crank sensor is by pluging a scan tool and monitoring engine rpms while cranking the engine, if 0 is displayed or something irratic like jumping from 200 down to 40 etc the sensor is bad or the reluctor wheel is damaged, or the circuit is faulty. The computer does not detect engine speed and therefore cannot fire the ignition respectively. You can check the sensor with a dmm but the voltage readings can be in range and the sensor still be bad. The correct way to test the sensor is with a dmm with a built in ocsilloscope which will display the pulse wave the sensor produces. Should be a steady and even display of squares, interrupted by smaller square everytime the crank gears larger gap passes by the sensor. You can also use an analog vm and watch the pointer tick everytime the crank turns. The specified range is anywhere from 1.3-1.6 volts. Again the sensor may still function in this range but still be bad. You also want to check this voltage at the pcm connector to insure the signal is being delivered there. And also check the ref signal to the sensor with the ignition on and measuring voltage across the ckp connector terminals should be 1.4 volts.

If you have correct ref voltage, and correct feed voltage at the sensor and ecm terminals, and there is no visual fault in the circuitry and connections no damage to the crank reluctor wheel, and you have no spark suspect a faulty sensor.

[daewoomofo]

if no spark is your problem id start with the coil pack

[Trey05Woo]

Well a faulty coil pack could be a culprit, but in a dis the coils only fire if they receive a signal from the ecm, which activates them only via a crank signal. For that reason you want to be sure all these are inplace before swapping out coils.
You can disconnect the coil pack and back probe the pcm connector c6 to ground. Should measure 1.4 with ignition open, and 1.6 with the engine cranking. If it does not then the problem has to be the ckp.

[daewoomofo]

is the 1.4/1.6 in volts? thats good info to know. thanks

[wjkov]

Thanks for all the responses - this site is great. It is a 1.6
To daewoomofo & others: I had a service guy put a scanner on it and he had no reading at all (i.e. no communication with ECM) and he told me that it was a bad ECM. So I replaced it - lo and behold this was not it (I should have known better then to take the initial advice - but the car was in my work parking lot and I was in a hurry). Anyways, since then I have towed it home and in garage now so I can do a more detail look).
1) Timing belt was first thing I checked - it is OK.
2) I did a visual check on the harnesses inside the car and appears OK (I did this because I saw a recall on similar model for harness on pass side).
3) Checked spark at plugs and I got a real weak spark from one plug once then nothing at all.
4) Checked the rel. wheel and everything looks great.
Also, the way it died and the way it is cranking (i.e. no spark at all) indicated that it was likely not the coils. There was no misfires or similar rough running before it quit indicating one of the coils were going bad and it is unlikely both would go bad at same time.

Anyways, I found the link here to the pdf Service Manual and Wiring Diagrams which indicate the procedures and proper V and Ohm for multiple wires and sensors. I will be spending the weekend going through the specified checks.

Trey05Woo: Thanks man. It sounds like exactly what I was thinking. Please correct me if I am wrong but is the Cam Sensor only for the fuel injector and the Crank Sensor only for the spark? This is what I am assuming.

Thanks agian guys, your help is greatly appreciated. I am an old school car guy with experience on carburated 318s and 350s - electronics is somewhat new to me. Ohhhh the good old days when you could smell the gasoline running through your motor and know exactly what was wrong just by the sound and smell.

[Trey05Woo]

Ha ha ha times have definitely changed but I much prefer to diagnos a no start with a scan tool, than to be checking for warped points, or fetch cold rags to smother mechanical fuel pumps with lol.

Dont know why that tech automatically assumed ecm without checking power and ground circuits accordingly. Most likely the scan tool used did not have the correct cartridge or keys to communicate with asian obd...

Defintely sounds like an intermitten loss of crank signal, most probably bad ckp but check it all well.

The cam sensor on this particular system only controls injector pulsation. It will not cause a no start or stall. It may cause an extended crank symptom though, and almost always sets a dtc. BUT make sure to check the ground circuits, as both do share the same ground, and a short to ground will cause a no start and as I stated there is a bulletin to correct this.

Just verify ref voltage of 1.4 v and visually inspect components and connections, but you most probably bad ckp. The crank wheel has passed by that sensor 10 quadrillion times so what more could you ask for.

[wjkov]

Thanks Trey05woo, It looks like my first check will be the grounds instead of going through the whole system checks. Maybe save me a few hours.

I still prefer the vehicles where you could fit a small person between the motor and the fender and still have room for a torque wrench. In fact after this work, I have the pleasure of getting my U.P. Cadillac ready for some winter plowing - a simple carb. rebuild and a new uni aaaaahhhhhhhhhhh.

[wjkov]

Okay guys final update (for this carwoo anyway). And oooohhhhh the leasons learned. Turns out it was the timing belt!!! The teeth on the belt ripped off at the bottom so it was not visible until I removed the bottom cover. From above, the belt looked great and the tension was good, but I did not notice that the belt never turned while cranking. Anyways, this was not all, after replacing the belt I was able to determine that the #4 valve was bent and useless - although I did have great pressure on the other three.
So leason learned CHANGE YOUR TIMING BELT AT 100,000!!! EVEN IF IT LOOKS GREAT. I know the manual says 120,000 (or something like this) but do it! This one was at exactly 120,000 and I could have had it done at 100,000 when I replaced the gaskets - so much for saving a few bucks.

Anyways, instead of fixing this engine (about an $800 to $1,000 job), I bought another used Lanos for about the same price with 65,000 miles and this one will sit in the yard and be used for parts over the years.
Thanks for all the help guys.

[Daniel]

Hi wjkov,

100,000 (miles?) is way too late IMO for the 1.6DOHC. User's manual for my 2000 Nubira (same engine) refer to 90,000km (54,000miles) or 54 months.

I change the timing kit complete (with water pump) at 60,000km according to the latest service manual I have.
There's maybe a TSB about this but I can't locate it.

[Trey05Woo]

Wow man crazy, your car has 120k and you never replaced the belt? That might be a record man lol. Or maybe a service was done previously and the replacement belt failed. Timing belts on these cars fail at 40k miles sometimes. My Woo is a tbelt surviver and it had 36k miles when I aquired it. I recommend 30k service intervals for all Woos as cheap insurance.

I would highly recommend you change the belt on the salvaged engine soon just incase, cause 70k+ miles is already in the danger zone.

Did you finally have an intermitten spark issue? Or did you determine the spark was fine?

[MMamdouh]

replace the T belt at 40K kms and the tensioner and water pump at 80K kms

MMamdouh

[wjkov]

I stand way corrected - I guess I was living on borrowed time for woo long.
Yeah I am replacing this belt ASAP.
Thanks guys. At least I have two twins in the drive now - one silver one white. One of which goes to the back 40. Any suggestions from anyone on winterizing/storage things I should do????

[Trey05Woo]

120k is pretty damn impressive. If infact it was all OEM I think its pretty safe to say it might be one of the first cases of longevity. I for one have never seen a Woo hit 100k with original timing belt/components.

As far as storage goes, same as all vehicles. 1/2 a tank or less of fuel, water remover in the tank, purge the fuel out of the lines/rail. Make sure the proper coolant mixture is present, or drain the coolant entirely. Replace the oil with the cold grade (5w30), and remove the batt store it inside...