# camshaft position sensor problem



## hyperion (Sep 17, 2009)

Hi! I have a problem with ls2 camshaft position sensor. The car didn't start very well and was low on power. So we hooked it to a computer. It said that problem was with this sensor. I bought a new one, but the problem was not gone. Checked the wires from the sensor to the ECU and they were all in good condition. What to do next ? To my mind, the only place where the problem could be, is the ECU. The sensor wires have been changed in one part, maybe it had short circuit and "burned" something down in the ECU ?

Any ideas ?


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## B-ville Goat (Oct 5, 2008)

Could be the ECU. Not sure how to test that theory unless you can swap one from another car to test.


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## Lautinjr (Mar 27, 2010)

To diagnose you'll need to hook a scope to the Cam position sensor connection to monitor if the signal is cutting out or not. A voltage drop on the wiring would be a good idea to. Alot of times the wiring is shielded to prevent increased resistance from increased heat if it has been repaired improperly this could be causing a issue. I think the first think you should really do is a crank position relearn then see if the car improves.


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## hyperion (Sep 17, 2009)

Lautinjr said:


> I think the first think you should really do is a crank position relearn then see if the car improves.


Sorry for stupid questions, but how do you do that ?


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## HP11 (Apr 11, 2009)

hyperion said:


> Sorry for stupid questions, but how do you do that ?


You have to do the 'CKP sensor relearn procedure' for PCM replacement, engine replacement, crankshaft replacement, crankshaft balancer replacement, crankshaft position sensor replacement, or any engine repair which disturbs the crankshaft/harmonic balancer to crankshaft position sensor relationship. Now someone correct me if I'm wrong but I'm pretty sure you need a Tech 2 (and the skills)to do that. Dealership or shop (one that knows what they're doing.)


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## 87GN06GTO07IRL (Aug 10, 2009)

HP11 said:


> You have to do the 'CKP sensor relearn procedure' for crankshaft balancer replacement, or any engine repair which disturbs the crankshaft/harmonic balancer to crankshaft position sensor relationship.


I put my Slp balancer on in my driveway and didn't have to do a relearn.


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## Lautinjr (Mar 27, 2010)

> You have to do the 'CKP sensor relearn procedure' for PCM replacement, engine replacement, crankshaft replacement, crankshaft balancer replacement, crankshaft position sensor replacement, or any engine repair which disturbs the crankshaft/harmonic balancer to crankshaft position sensor relationship. Now someone correct me if I'm wrong but I'm pretty sure you need a Tech 2 (and the skills)to do that. Dealership or shop (one that knows what they're doing.)


You can do it with any decent diagnostic scanner I did one on a Aurora last week with My Snap On Solus. I know the old brick was capable, and the new Pegisys is capable i'm sure most are. You just go to the protocol select atart, set the e- brake, hold the brake, and rev to 2500 RPM and hold it till it says done. Just don't forget to set the E-brake I always think that step is for safety but it actually won't start calibrating till it's set.





> I put my Slp balancer on in my driveway and didn't have to do a relearn.


You don't have to do it as in the car won't run if you don't, but it can slightly affect your timing and if it was to be very far out it can cause from a light to dead miss fire and a MIL set. Usual Codes are - Cam and crank out of Sync, sometime with a random misfire code also. Only twice have I seen it actually set a light. Once when I changed a cam sensor on a Denali like 97-01, and the other a harmonic balancer on a older bick 3.8L I think it was like a 96-98 model. I'm sure boh times it caused the problem because of the age causing slack in the chain which may repair resulted in throwing the numbers further off enough to actually casue the issue.


Most shops charge $70 to do it which is really high for a 5 minute job that can be done in the parking lot, but like me I have 7K invested in the equipment and expect to be paid decent for my investment.


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## HP11 (Apr 11, 2009)

I'm just going by what I've read. Not always a good thing w/o doing further research. I've only had this vehicle about a year and really haven't done much work with other OBDII based vehicles we've owned. In looking at my scanners instructions, I see that it's also capable of doing this procedure.


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## hyperion (Sep 17, 2009)

problem solved, the ECU was fine, but the engine block was wrong  somebody has put the 5.7 liter version in this car but left all the 6.0 sensors and ECU... nice mix I have here


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