O.K. guys, I have asked/pleaded, etc., for help on this. And I am asking again.... Please- this could be you, someday! My C5 has been in the shop for 7 (Yes, SEVEN!) weeks and this "crank trigger sensor circuit failure", code p0336, I believe, has so far eluded some of the brightest minds I have ever met, known, etc.. The car has had the following done to it: A different PCM has been installed with a new program, 3 different crank sensors tried, all new wiring from this sensor to the PCM installed, the oil pan dropped so that the reluctor wheel could be inspected for "shifting" on the crank, the crank thrust checked, different ignition coils installed, a different intake manifold tried, new grounds for various circuits have been done, and thus far, I have a $1500.00 bill for labor and it runs as good as.... it did when they started on it!!!! That is, after about 5 minutes of running time, it throws this code and runs like crap! When we discovered that this code was set at about the time the engine coolant reached 190 degrees, W2W even installed a resistor to "fool" the computer into thinking that the motor was up to temp, but it still was a "no go"! It is becoming obvious that this is an operating temp- actual 180 and/or hotter temp that is triggering this code. But thus far, no matter what we/they have tried, IT WILL NOT RUN, for over 5 or 6 minutes anyway. HEELLLLPP!!!! PLEASE!!!!Are we all as lost on this as the pro's at W2W, Cartek, etc.? SOMEONE out there must know someone who has had this problem. With all the electrical circuits there are on a C5, I GUARANTEE some of us will eventually have this situation. I am hoping someone will help. Even W2W is pulling their proverbial hair out! They have asked me to offer any and all suggestions I, or anyone else, might come up with. Is this the first unfixable car in auto history?

 

Here's some information for you.

http://www.gearchatter.com/viewtopic10350.php

Says here to check your grounds.

http://forum.efilive.com/showthread....ighlight=p0336

 

Nothing is unfixable, but the C5 electrics are very complex.

One thing that you should be very aware of is that pretty much
every sensor on the car is read by the computer on the GROUND
side of the circuit. That is, power goes to the sensor, but the
*signal* from the sensor is read by the computer on the return,
or ground, side of the circuit. This means that a marginal ground
can corrupt the values returned by the sensor. For sensors that
return a low-voltage square wave (crank trigger, cam sensor, etc)
grounds are even more critical, since the edges can be badly
rounded and the amplitude blunted by a poor ground. This is
almost certainly what you are seeing.

Also, note that ground faults can *telegraph*. That means that
if another sensor on the line has a higher return voltage, say
for instance a temperature sensor, then as the return voltage
from that sensor rises in response to whatever it is measuring,
it can corrupt the signals from lower-voltage sensors because
of the bad ground (the voltage from the higher-voltage sensor
is feeding back into the ground of the lower-voltage sensor as
electricity tries to find a way to ground around the bad chassis
ground).

In particular, check your grounds inside the car, at the PCM,
and inside the fenderwell, at the TAC module, as the computers
must be well grounded to get clean readings.

One test you could try is to fool the engine into thinking that
the temperature is always COLD. This should keep the car
out of closed-loop and keep a bunch of sensors out of the
picture. See if that gets you past the 5-6 minute mark. If
so, you're on your way.

Anyway, it sure sounds like a grounding (or maybe even
a short) issue, but it may not be the circuits that are
throwing that codes that are *causing* the codes, the
computer is reporting the problem, not the cause.

Good hunting.

 

Not much help I know but I had some "telegraphing" issues also that screwed up a totally different sensor. Good luck.

 

Check the ground wire on the driver side. My buddy had issues after a header install and found that the ground wire had snapped....Tony

 

Grounding problems come up about once a week. I keep this handy in hopes it may help track down the issues. When cleaning grounds, don't just tighten things. Take the ground apart, clean with wire brush, coat it with a marine terminal coating, then put it all back together.

 

Wowzers.... keep us updated =(

 

Number 11 is the most common problem.

Randy

 

Mike

I feel for you. I once had a 98 from hell!! I will dig into the circuit tonight and see if I can give you some recommendations.

One of the very first things that I recommend checking are the condition of your female connector pins in the connectors in that circuit!!! There have been NUMEROUS instances where the female pins are spread so far apart and do not make good contact with the male pins! Been there, done this too many time not to have you check it. The wheel speed sensor wiring harnesses are bad for having this issue!!!

The absolute best way to check to see if the female pin is good is to do a PIN PULL TEST on the female connector. You will need to get a male pin the same size as the male pin inside the connector that you checking. Dealers have boxes of universal and replacement pins that you can use to find a male pin of the correct size. Just insert the male test pin inside the female pin and see if the female pin has a good grip in the test male pin. If it doesnt, you most likely have found the problem!. You can try to maniplute the female pin to get a better contact on the male pin but, if it test bad, just replace the connector!

Please keep us infoprmed on your progress or lack there of.

Bill Curlee

 

So are these slutty female pins... or is the male pin possibly an asian part?


sorry couldn't resist.

 

I found number 11 to be busted when I did my heads/cam. I bought a new crimp-on ring and fixed it but it is a really flimsy ground. Some heavier gauge with a little beefier crimp-on would be nice....

 

Steve Spencer @ Bryner Chevrolet in Jenkintown PA..
If you want it fixed, it will be worth the flat bed bill.. trust me..
215-886-3140
Steve is THE #1 dealer Corvette Only tech in the country..
Highest test scores ASE & GM...
Written up on all trade & GM journals..

Trust me on this..
If you can't get it done locally... Get it to Steve Spencer..
He does cars from ALL over, and EVERY person swears by him..

 

 

Thanks to all who have tried to help.... but here is an update... W2W contracted in some techs from G.M....electronic techs.... who found.... NOTHING!!! HOWEVER, they did find that when the code is tripped, it is actually NOT in the crank trigger circuit.... Apparently, 2 injectors start randomly misfiring and the code is set as the PO336. It is always these 2 injectors... sometimes only one of the two....sometimes the "other" of the two....sometimes both!! A Big Stuff 3 stand alone was tried, bypassing the factory ECM AND the factory harness, as well....still did it!!!! !!!! W2W then tried checking the crank circuit with an oscilloscope, and when the code was set, the crank trigger circuit was still O.K.!!! They then tried to do the same with the cam sensor circuit, and... BINGO!!! It is the cam sensor circuit.... or so it seemed. They had tried a new cam sensor and new feeds, both power and ground.... still sets the crank code??!!!! They have determined that it is inside the motor itself.... the cam was suspected. When it was pulled....Bingo again.... the very first lobe on the cam adjacent to the timing gear has been damaged somehow. It is scored the width of the roller wheel, follower, etc. But they are not convinced this is what is causing the problem!!! When the new cam is installed, with new lifters, they are planning on running the motor on the dyno, not to tune, but to see if it will run for longer than 7 or 8 minutes () before tripping the code. Maybe the cam sensor has been distanced from the cam itself from excessive bearing clearances, thereby letting the signal "weaken" by being physically farther away from each other??!!! This is unreal! Anyone EVER had this problem before? Please....H-E-L-P!!!

 

As my update said on 11-17, the cam is out. But Kurt Urban at W2W does NOT believe that it is the cause of the trouble. I bought a VERY EARLY set of AFR 225's a couple years back and had "upgraded" ( ) to a set of REV valve springs. They broke right away, one even before they could tune the car!! I believe that the damaged lobe is from a damaged lifter- the roller wheel- as when the spring broke, it probably damaged the lifter, which in turn took out the cam. But it took about 30 thousand miles for the problem to surface. When they pull the motor to replace the lifters (I have ARP head studs) and install the new cam, they are going to run the motor on the dyno so they can monitor the problem, and hopefully find the cause of it. If it runs longer than 7 or 8 minutes, that would be a step in the right direction! . If it makes it 1 or 2 hours, were good to go. If not, it is out of the car and easier to troubleshoot. Thanks for your help, Bill.