Camshaft & crankshaft position error codes plus stabilitrak and low power all at once

[baskervi]

We have a 2007 Yukon XL with a 5.3L engine. Recently, the check engine light came on (error codes P0341 for camshaft position sensor, P0335 for Crankshaft Position Sensor Circuit, and second P0335 for Crankshaft Position Sensor Circuit). A few days later, the Stabilitrak message came on followed by the Low Power Mode - we could barely limp across a parking lot at this point.

About 2 years ago, the Stabilitrak message pop up followed by the Low Power Mode, and it turned out to be the passenger side catalytic converter. This truck had an oil consumption problem that was fixed by the dealership several years ago, and I don't believe that's a problem any more. I never could figure out how a catalytic converter would impact Stabilitrak, but it was gone after the catalytic converter was replaced. I'm thinking these other problems are causing this, but I'm not certain. I've physically checked the cam position sensor and wiring as best as I can, and it looks OK. Trying to get my multimeter leads around either of these sensors to test seems like a difficult prospect. Should I just try to replace these? Any suggestions? Thanks

 

[Dwayne Chatman]

Did you ever find out what the issue was? I am having the same issues with my 07 Yukon XL 5.3L and I have changed the camshaft sensor and the wiring harness and the crankshaft sensor and still getting the P0335 and P0340 and P0341. Can someone tell me what is going wrong or what the problem could be.

 

[Big Mama]

Start easy. Check the ground cables at both ends. They are famous for causing problems you wouldn’t normally attribute to a battery or connection problems. Let’s ask James @swathdiver he’s a whiz at codes.

 

[swathdiver]

Did you ever find out what the issue was? I am having the same issues with my 07 Yukon XL 5.3L and I have changed the camshaft sensor and the wiring harness and the crankshaft sensor and still getting the P0335 and P0340 and P0341. Can someone tell me what is going wrong or what the problem could be.

It's probably time for a new ECM. Get your hands on a Tech-2 and a subscription to ALLDATADIY for the shop manual and you can properly diagnose. With the Tech-2 we run live plots of the Crank and Cam sensors and see if they track with rpms. Then take a multimeter and test circuits for resistance and voltage.

For example, with the ignition off, disconnect the CKP crank sensor. Test for less than 1 ohm between Terminal B and Ground. If greater than 1 ohm, test for an open circuit. If that passes, it's time for a new ECM. Also, turn the ignition on and test Terminal C and Ground for 4.8-5.2 Volts. If less, look for a short, if more, look for a short to voltage. If within range, replace the ECM.

Also, you have to be absolutely sure that you installed them correctly, without damage. Aftermarket parts are generally not received well by the ECM.

 

[Dwayne Chatman]

It's probably time for a new ECM. Get your hands on a Tech-2 and a subscription to ALLDATADIY for the shop manual and you can properly diagnose. With the Tech-2 we run live plots of the Crank and Cam sensors and see if they track with rpms. Then take a multimeter and test circuits for resistance and voltage.

For example, with the ignition off, disconnect the CKP crank sensor. Test for less than 1 ohm between Terminal B and Ground. If greater than 1 ohm, test for an open circuit. If that passes, it's time for a new ECM. Also, turn the ignition on and test Terminal C and Ground for 4.8-5.2 Volts. If less, look for a short, if more, look for a short to voltage. If within range, replace the ECM.

Also, you have to be absolutely sure that you installed them correctly, without damage. Aftermarket parts are generally not received well by the ECM.

Thank You for your help. I will find a shop that has one instead of a dealership. If U need a ecm would you recommend me buy a new or get a used one.

 

[swathdiver]

Thank You for your help. I will find a shop that has one instead of a dealership. If U need a ecm would you recommend me buy a new or get a used one.

I always strive for new OEM parts. A new ECM will have to be programmed to your vehicle.

 

[Dwayne Chatman]

I always strive for new OEM parts. A new ECM will have to be programmed to your vehicle.

Ok. Thank You. If that's my problem that's the route I will go.

 

[Dwayne Chatman]

Ok. Thank You. If that's my problem that's the route I will go.

I found out that I had a broken wire and a dirty ground wire. Thanks for all your help.

 

[Big Mama]

Another one chalked up to grounds and wires. It’s amazing how often it’s this. Thanks for closing the loop for the next guy.

 

[Rocket Man]

Start easy. Check the ground cables at both ends. They are famous for causing problems you wouldn’t normally attribute to a battery or connection problems. Let’s ask James @swathdiver he’s a whiz at codes.