Cam sensor ?

[G's Chop Shop]

I have a little issue with the engine taking a while to start. I have to crank it for about 6-8 seconds for it to start. It will start after it turns aroung more than 10-12 times but it does run. I ran a diagnostic and it tells me that the cam sensor is not reading. The engine is out of a 2010 camaro w/18 miles on it. It came with all the sensors. I am running a GM Performance wiring harness with ECU, pedal and everything needed for the swap. The cam sensor that came with the motor has a different plug. It has the same amount of contacts(2) but the plug on the harness would not plug into it. I cut the little guide in it and it plugged right in but won't read it. Would I have to put another cam sensor off another car or does domebody sell a harness for this.

Any help would greatly be appreciated!!!!!

[camcojb]

Originally Posted by G's Chop Shop

I have a little issue with the engine taking a while to start. I have to crank it for about 6-8 seconds for it to start. It will start after it turns aroung more than 10-12 times but it does run. I ran a diagnostic and it tells me that the cam sensor is not reading. The engine is out of a 2010 camaro w/18 miles on it. It came with all the sensors. I am running a GM Performance wiring harness with ECU, pedal and everything needed for the swap. The cam sensor that came with the motor has a different plug. It has the same amount of contacts(2) but the plug on the harness would not plug into it. I cut the little guide in it and it plugged right in but won't read it. Would I have to put another cam sensor off another car or does domebody sell a harness for this.

Any help would greatly be appreciated!!!!!

I've usually found if the cutout in the plug is different it's so the wrong sensor or harness lead can't be plugged in, like in the case of 1 bar vs 2 bar map sensors. In that case you can modify the slot and it'll physically work, although it may not be correct depending on map vs n/a or blown engines. On TPS switches I've had some combos where the leads had to be changed around in the plug to work correctly, when using one type of harness/ecu and a sensor from something different. It's quite possible that either the sensor has to be changed, or the wires may need to be in different slots on the plug to work correctly.

Jody

[Mike Norris]

I would like to elaborate a little more on what Jody said about pin locations and ask a couple questions.

Does the engine you bought have a short cam sensor harness that runs from the actual cam sensor in the timing cover down the the corner of the oil pan?? Or it there just the sensor in the timing cover?? What is the part number of the GMPP kit you purchased.

If the engine has the short cam sensor harness and ECM harness for the cam sensor will not plug into it, perhaps it needs to be plugged directly into the cam sensor in the timing cover instead.

And the opposite applies also in that if there is no short cam sensor harness and the ECM harness for the cam sensor will not plug into the cam sensor in the timing cover, perhaps it needs the short cam sensor harness.

I have seen some harnesses that have had the outer pins swapped and cause an issue and occasional backfire on cranking before starting.

If I can get a GMPP part number I may be able to tell you what wires from the ECM go to which pins on the cam sensor or short harness.

Hope this makes sense and helps.

Mike Norris

[camcojb]

good point Mike. I forgot they ran those short extension harnesses on some of the LS engines. Plugs are different on the cam sensor itself and the end of the extension I believe.

[G's Chop Shop]

^^^^you probably have a point! It did not come with a short harness you are talking about so I believe maybe that harness is what I am lacking. It only has the cam sensor by itself... no harness. And yes it does backfire sometimes like it is out of timing.

GMPP part no. for the complete harness is 19201861....I ordered it from Fred Bean (shopfbparts.com).

I think I have seen that cam sensor harness in a couple of corvettes I have worked on. Where would I be able to find one?

Thanks, I appreciate all your help guys!!!^^^^^^^^^

[Mike Norris]

I know they show a cam sensor jumper harness as far as the GM service manual goes, but I believe it is only available when you buy a timing cover and that would also inlcude a sensor. I would call Fred Beans since you got the harness from them and ask.

In the service manual for an LS3 Corvette, the wiring diagram does not show the the short jumper harness connector, just a direct ECM to Cam Sensor connector. Not sure why GM does that, but they do and I believe the two out pins swap in the jumper harness for some reason.

As a test you could just swap the two outer pins on the cam sensor harness from the ECM and see what you get if you already modified it to fit the cam sensor directly.

Hope this helps.

Mike Norris

[G's Chop Shop]

I will definitely try interchanging the wires.....see if this helps!

Thanks, Mike and Cam for all the info and suggestions!!! I really appriciate your help!!

[XcYZ]

I had the same problem when I got my car running. I got my LS7 from Stielow; it wasn't a crate motor, so it didn't come with that short pigtail harness. I didn't even realize that it was missing. I just plugged the engine harness in and it did exactly what you're saying - turn over for 6 to 8 seconds, then fire just fine. It threw a code, no cam pulse. I had a friend hook it up to a Tech 2, and sure enough, there was no signal (IIRC, it was high all the time). After looking at schematics and realizing that I didn't have that harness, the problem was found. For whatever reason, pins A and C are swapped within that 3 conductor harness that goes from the cam sensor to the oil pan rail. I have no idea why GM would have done that, but I simply used a Molex tool and swapped pins A and C at the cam sensor connector and all is good.

[G's Chop Shop]

Originally Posted by XcYZ

I had the same problem when I got my car running. I got my LS7 from Stielow; it wasn't a crate motor, so it didn't come with that short pigtail harness. I didn't even realize that it was missing. I just plugged the engine harness in and it did exactly what you're saying - turn over for 6 to 8 seconds, then fire just fine. It threw a code, no cam pulse. I had a friend hook it up to a Tech 2, and sure enough, there was no signal (IIRC, it was high all the time). After looking at schematics and realizing that I didn't have that harness, the problem was found. For whatever reason, pins A and C are swapped within that 3 conductor harness that goes from the cam sensor to the oil pan rail. I have no idea why GM would have done that, but I simply used a Molex tool and swapped pins A and C at the cam sensor connector and all is good.

I did not have time to check on this today but will for sure tomorrow. I went shopping a while back for a sensor with the same connector but never found one. I will definitely try this tomorrow. Hope all goes well.

Thanks, guys!!!!!!!!!!!!!