0340P code came up, replaced sensor with no results

[hlcinva]

I replaced the camshaft sensor and the van is still doing the same thing. When they read the codes it came up the the 0340P and the p1740. I am having my father-in-law help with repairing it and we don't know where to go from here...please help!

[tempfixit]

Originally Posted by hlcinva

I replaced the camshaft sensor and the van is still doing the same thing. When they read the codes it came up the the 0340P and the p1740. I am having my father-in-law help with repairing it and we don't know where to go from here...please help!

What year and engine????

Did you just replace the sensor or the syncronizer also. Have you checked the wiring to the sensor. Were the codes cleared after sensor replaced??

[hlcinva]

It is a 99. We just replaced the sensor and yes we took off the negative to the battery cable to clear the codes. I drove it all today and it seems to be worse than what is was. It idles fine when you 1st start it but then it starts to idle rough and the rmps start going down (although it has yet to die on me). It feels like it bucking, but I don't feel it at higher speeds. The worst thing is that it is SUCKING up some gas!!

[hlcinva]

ohh and it is a 3.8

[tempfixit]

Originally Posted by hlcinva

ohh and it is a 3.8

What were the symptons before replacing sensor and was the P1740 code also present???

[94LebConv3La604]

The bucking at low speeds and the poor fuel economy may be partially due to the P1740 code which has to do with the TCC most likely not locking up or stuttering.

[94LebConv3La604]

And as temp suggested, check your voltages at the CMP connector with the Key On Engine Off. The center terminal is for signal and the terminals to either side are + and -. The + terminal should be to the right of the smaller tab as you are looking at it with the small tab on the bottom, big tab on top. You should be getting more than 10 volts on the + terminal. If you aren't, there is a problem with the circuit between the CMP and the PCM.

[tempfixit]

Check this thread out for the Code P1740:

http://www.automotiveforums.com/vbul...ght=p1740+code

[hlcinva]

Both codes were on when we changed the sensor and now that we cleared the codes the check engine light is no longer on and has not come back on as of yet.

[hlcinva]

It was doing pretty much the same thing as I explained earlier but worse. The RPM's go down to the half way mark between the 1 and 0 (I guess that's 500.) when the idle goes down and feels like it going to die but it never does then it goes back up to almost the 1. I hope I am making some sence here. I am a little illiterate when it comes to cars.