P0340

[top_notch]

2003 Chevrolet Trailblazer, with 89,000 miles.

Motor is the Vortec 4.2 I6.

Has code P0340 (Cam position).

Car was occasionally stalling/stumbling.

Replaced the exhaust cam VVT actuator. The actuator was leaking internally and there was oil in the connector. Cleaned connector and installed new actuator. Also replaced Cam position sensor. (non ACDelco)

Car now run flawless, no stumbling, no fuss.

But car still throws a P0340 code. I don't have a tool to be able to graph the cam sensor values. I did test the actuator and it has 12V at start up and does actuate (I bench tested it).

Not sure where to go from here.

My only thought is the sensor may be flaky since it's off name brand and it needs an AC Delco sensor. I did check the wiring and couldn't find any issues.

. I don't have a graphing device (only a multi meter) so I am shade tree handicapped.

I should note there are no other codes and truck runs/drives great with no issues.

Any advice appreciated.

 

[Maverick6587]

Have you tried clearing the codes with a scanner? If you don't have one, just unplug the battery ground for 10 minutes to clear them. If it comes back after that I would say you need an ACDelco sensor. These engines are very particular about electronic parts.

I replaced my cam sensor three times (with two different brands) before switching to an ACDelco cam sensor, that fixed the error.

 

[top_notch]

Yes. I did erase the codes with my scanner. The code comes back pretty quickly.

 

[Maverick6587]

OH, Welcome to GMT Nation! Just noticed you were a new member.

Yup, looks like you're running into the same problem I had then. Luckily the cam sensor is one of ACD's lower priced parts!

Did you replace both the VVT sensor and the cam sensor with non ACD parts?

If that still does not fix it your issue I would do an oil change.

Edit: If you have not done an oil change in awhile or you're close to needing one, I would do the oil change before you replace parts. Oil changes usually fix issues with the VVT sensor.

 

[top_notch]

Actually both replacement parts were not ACDelco. I'm regretting that now, though!

I'll take a look at the oil change interval. This is my wife's truck so I'm not sure where we are at on the mileage.

Bought this dealer serviced with only 45,000 miles for a song but it's been nothing but problems.

 

[mrrsm]

Try removing the CPS (Camshaft Position Sensor) Connector and examining it... and the wires and pins inside as well as searching along its length for any breaks or cuts in the wiring. Using CRC Electrical Solvent works great for dissolving anything oily or dirty inside of the Connector Weather-pack 'innards' to improve conductivity, too.

 

[Maverick6587]

Actually both replacement parts were not ACDelco. I'm regretting that now, though!

I'll take a look at the oil change interval. This is my wife's truck so I'm not sure where we are at on the mileage.

Bought this dealer serviced with only 45,000 miles for a song but it's been nothing but problems.

You might be ok with the VVT sensor not being ACD. Try the oil change first and if that doesn't fix the issue I would start with changing the cam sensor first. That's the one I changed three times before switching to an ACD part.

Once you get this resolved, if you haven't already, I would look into changing front and rear differential fluid (quality 75W-90 gear oil).

Edit: removed the transfer fluid note, since he has a 2WD vehicle.

 

[top_notch]

I should mention it's 2WD.

I'm going to change the oil, then the sensor with an acdelco one if the code continues.

Spotted fluid dripping so now something else is wrong with this thing.