Camshaft Position Sensor and PCM error code PO343

dsmisfits · February 21, 2013

Hello,

Recently I started bought a 2001 2500HD with 8.1. I started having the check engine light come on, I cleared the code and a few miles later it comes back on. Scanned the codes and it has only the PO343 show up. The dealer told me to replace or try cleaning the Camshaft Position Sensor. I purchased a new one from the dealer and installed it. About 2 hours later the light came back on. The tech then told me it could be a bad PCM, I am not familiar with the PCM, I am assuming it is different then the ECU. If so, what do you recommend? a guy at work told me to replace it with a jet PCM. If I try and get a stock PCM does it need to be flashed? If anyone out there has had this problem please let me know.

gmtech4 · February 22, 2013

you are getting caught up in the "throwing parts at your truck to fix it " game

why not spend money wisely and have the code diagnosed properly ,,,,,,if the dealer put the sensor in and it didnt fix it ,,it would be a comeback and you wouldnt pay for it ,,,but because YOU replaced it ,it is on you ,,,,

why did you do that ????????

stop throwing parts at it ,,

yes to having the PCM flashed ,they come empty

oh and welcome !!!! lol

dsmisfits · February 22, 2013

Well, the part was 117, the dealer wants $87.00 to scan the truck and 2hrs labor for installing the part and still have to pay for the part. Plus they could not get the truck in the shop for two weeks. I can replace the pcm and the sensor for what they charge for labor. But, thanks for the information you provided.

ATMINF · February 22, 2013

Did the code get cleared in the first place? If the original code never got cleared the computer might not "realize" the part has been changed. I understand that the OBD2 systems "learn", but you could possible just take it to a auto parts store to clear the computer. I know my Scanguage has that ability.

dsmisfits · February 22, 2013

Yes, the code was cleared using a hand held device. The code does not came on right away after it has been cleared. It usally takes about 1hr to 2hrs of drving around before the check engine light comes on. The truck does not show any signs of proble, other than the check engine light.

gmtech4 · February 22, 2013

you dont get what i mean ,so im out

Daryl LBZ · February 22, 2013

you dont get what i mean ,so im out

The code he has is for the camshaft position sensor which he replaced. So that didn't work obviously. So what do you think it is then mr GM Tech?

Sent from my Samsung Galaxy S3

scooby5121 · February 22, 2013

Could be a wiring problem, bad connection, check timing, and clean connections.

This could be something you could do before you start to throw parts at it.

Then bring it in if problem persists.

Scooby

txab · February 22, 2013

+1 on checking wiring next. BTW, I know of several people who tried the PCM/ECM swap to no avail.

Also....

Have you searched?

https://www.google.com/search?hl=en&client=firefox-a&hs=Tgt&rls=org.mozilla%3Aen-US%3Aofficial&biw=1680&bih=848&q=site%3Agm-trucks.com+p0343&oq=site%3Agm-trucks.com+p0343&gs_l=serp.12...80922.83057.0.84757.3.3.0.0.0.0.42.119.3.3.0.les%3B..0.0...1c.1.4.serp.Tj11YJAJ_H8

gmtech4 · February 22, 2013

lol

crystal ball broke 19th feb ,sorry lol

dsmisfits · February 28, 2013

Problem fixed, I changed out the camshaft position sensor with a new one from auto zone (hard to find part had to go with one from an 02) and took the other one back to the dealer they tested it and it was a bad sensor and they gave me my money back. Total cost 92.00.