FAQ: P0341 Camshaft Position Sensor (Cam Sensor / Timing Chain)

Thanks for the troubleshooting guys. I've had a few people tell me it may need a reflash, but I suppose a newer one wouldn't hurt. It would give me an excuse to get an Intense programmed one. I'd rather get tuning software but I'll compare prices nonetheless.

Still gonna keep checking wires/harnesses and so forth but everything you guys have told me makes total sense.

Thankfully, this issue has been fixed. The culprit was a corroded broken wire running from the ecm to the coil module. The wire has been replaced and the code has totally gone away, and the car drives better than ever! Thanks for all of your help guys. It helped me more than any mechanic's hasty advice would.

Was it broken at the ICM or the main electrical connector on the firewall?

The firewall. The ICM was where I first visually inspected too, too bad it wasn't there.

ZEP wrote:

The firewall. The ICM was where I first visually inspected too, too bad it wasn't there.

Yep. I haven't had this problem myself yet (sign-of-the-cross ) but from what I've read on the board that seems to be the common failure point for under-hood wiring...

Sorry you had to find it the hard way.

I would just like to note that I had this exact problem with my 98 riv this week. I went and checked the 72 pin connector from the ICM to the PCM to the left of the brake booster. Sure enough it was that broken 18 gauge black wire right in the corner of the connector. It looks exactly like the picture earlier in this thread.

I would advise anyone with a troublesome P0341 code to start with the wiring and definantly verify the components such as cam/crank sensor and PCM before buying new parts, it seems to be a recurring theme.

Also note to fix the connector i just backed it out with a bobby pin and soldered on some new 18gauge wire. The only hitch was that the white retaining clip in the connector no longer fit the connector so I had to trim it for that one connection. I'm not worried as i believe the connector will hold itself in. It took a respectable amount of force to push it out with the bobby pin.

Good luck everyone, I'm sure now as our cars age were going to find more and more problems of this nature,

L67 wrote:

Well my brother and dad were working on my car back home and found this:

The arrow points to the end of the black CPS wire that is cut from the circled plug in the big connector behind the trans dipstick that was mentioned a few posts up. It must've been weak or frayed when i was doing the rocker install, and all of the movement of parts to access the back VC tore it apart.

I'm getting this cam position sensor code now, a few weeks after doing my water pump. I'm thinking maybe the sensor got contaminated with all the coolant that was pouring on it, or I have this wiring problem. I took a quick look last night, for the pictured wiring bundle, behind the trans dip stick, but nothing jumped out at me. Is there a plastic cover over the firewall connector? The engine seems to start well, and run great though. I'll need to resolve this to get the car inspected in NY, by the end of June.

The SES light was off all day today. Not sure whether it is wiring or sensor related. If the magnet had fallen off, the light would be constant. Same for a completely broken wire. Has anyone resolved this with just a sensor change?

Well, I replaced both my cam sensor and crank sensors while doing other work on my Riviera. I cleared the codes and sure enough, the next day, the SES light was on again. I pulled the cover off the wiring connector and moved the wires around, but it was getting dark and I couldn't see anything. The next day, the light went off and stayed off for more than a week. Took a ride up to one of my Buick friends in Connecticut yesterday. He has a Tech 2 type scan tool that we hooked up.



After hooking it up. We were able to monitor the cam sensor signal with the engine running. While moving the wires around, I watched the display turn from yes to no, then back to yes again. I knew it was the same problem documented in this thread.

We shut the engine down, removed the front half of the harness connector. I located the black wire and it looked intact. Pulled on it a bit, and sure enough, it broke right off.






The front half of the harness connector has a sort of locking mechanism for the individual terminals. Its a white tab visible in the second picture. If you pull that out a bit, the individual terminals can easily be pushed out of the connector. Each one has a small weather seal.



My friend happened to have a box full of these new, so we hooked up a small section of black wire, soldered the new connector on, inserted it back into the front block, and soldered it to the feed wire.



Buttoned everything back together, started the engine, and checked the signal. It was there. Another problem solved. This Riviera bulletin board rocks Saved me a lot of aggravation and work.

Have I mentioned yet how much I f'n love this website? Sorry aa for the Semi profanity, but I've been chasing this damn code down and couldn't figure it out until now. Broken black wire.

HOWEVER, i repaired the black wire and cleared dtc's and did not fix the problem. Cam sensor has been replaced, crank sensor has been replaced, harness to each of them and the coils have been replaced.

ABS light is on, Traction OFF light is on and CEL will be on soon. Gotta be a wire broken somewhere.

Bowersk wrote:

ABS light is on, Traction OFF light is on and CEL will be on soon. Gotta be a wire broken somewhere.

don't wig out yet - IIRC you recently got this Riv and the CEL was on. Right?

One thing that can happen is that when the CEL comes on for a minor thing and people are told to ignore that minor thing, other problems that will trip the CEL happen and they accumulate. Eventually car runs like hot poop and they sell it for a song.

Keep pulling the codes, posting, and troubleshooting and over the course of some weeks you should be able to clear up all the codes. If your "black wire" was broken you'd have had to fix it anyway.

As for the current lights, for the Traction Off it could be a wire to an ABS sensor got chafed or has busted; need to check. Easiest to check by pulling each wheel and looking carefully at the wires to the hub sensors (they are in the hub).. . Sometimes you can repair those wires; usually you have to replace the hub, though

I don't remember -- did you get that factory manual yet?

Albertj

Yeah I have both the manuals. Been troubleshooting this particular cps circuit performance code for a week now. Thought I had it fixed and then it came back. This car had no trouble indicators before I pulled the old motor. Has to be wires in the engine bay doing all this.

Well I think the CEL is gone thanks to the black wire. I did a much better repair on it this morning like your suppose to repair a broken wire and I let it run for over an hour this morning and it never threw the light again. I think maybe I was automatically assuming the rough idle was tied to the CEl but I guess I was wrong. HOWEVER, I am seeing cylinder misfires now where before I was only seeing 0's. Going to take my plugs out and check the gaps again and then change me some plug wires this weekend. The traction control off light and ABS lights will just have to wait their turn.

I have had this PO341 code for two days now with a PO401 EGR code as well. Changed camshaft position sensor,harness that plugs into coil packs and associated sensors. I took EGR off cleaned real good, seemed to be working fine, and replaced gasket, reinstalled. Put everything together, checked for codes and seen none. After driving a few blocks I got two codes, both PO341 again, which sounds like this same black wire problem? I cleared them and drove for fifteen minutes and now its showing three codes the two PO341 and one PO401. Im not sure where the PCM is and Im not sure exactly what else it could be? I remember reading something about the cam magnet?, the relearn or something needed to be done after changing camshaft position sensor. Is this necessary in all cases when sensor is changed? Could it be wiring I overlooked? Especially since I never had these codes before, until I unhooked some wiring on the harness controling EGR, and associated sensors in its path. Should I just unwrap all that wiring and visually inspect it?

I took pix of the install. I took water pump pulley off and loosened both belts. I try to keep my computer close to me when workin, and use this site for refrence and pix, like the belt diagrams and pix. After disconecting power steering pump, I removed the front motor mount completly. I took motor mount off so I could easily reroute the harness that runs to coil packs and sensors in this path. I then changed the camshaft position sensor, and reassembled in reverse order. I also checked codes before restarting and seen none at first. I also topped off the supercharger with fresh oil, as it was low from yesterdays swap and coupler, which I also used this site to help me do. Thank you all who helped, hope this helps someone along the way, have hundreds of pictures under the hood and of most all possible angles and views if needed.

Update. As of today I drove normally, and the car ran fine. It is weird. It displayed SES again after about half an hour at operating temp, and I tried clearing it and after reading it shows 3 codes again. PO341,and two PO401 codes. I eliminated the cam position sensor and the harness that feeds it and the coilpacks/crank sensor. They are new. I tried driving with the traction control on, and it didnt come back until I turned traction control off. I know I read a thread about this some where here, and tried driving with traction control on, which I cant stand. Thought I had it figured out, but it returned shortly after. Im inclined to believe it is a broken,chaffed or loose wire in the harness from the firewall, that feeds the EGR valve and associated sensors in that path. It also connects to the harness I just changed. I dont think its the magnet on the cam itself, although it does have 160K on it. Any input,advice or comments that might help would be appreciated.

1) please take another look at the pix that Larry70GS posted in this thread, I don't get the impression you checked those wires yet, which I understand because they do not appear to flex. Do you think you could go look anyway?

2) the PCM is accessible if you remove the glove compartment & door (it's one unit, undo a few screws on the piano hinge at base of door and it comes off... empty it first heh heh then remove the screws...)

My guess is there was a run of brittle copper used in some of that black wire -- that firewall connector does not get flex for beans but it would pick up vibration from the famous 90-deg V6 engine -- but that's only a guess. I don't have this problem on my '98.

Albertj

albertj wrote:

1) please take another look at the pix that Larry70GS posted in this thread, I don't get the impression you checked those wires yet, which I understand because they do not appear to flex. Do you think you could go look anyway?



Albertj

My wire looked OK at first, but the wiggle test confirmed that I was intermittently losing the cam sensor signal. I had it hooked up to the Genesis scan tool pictured, that let me monitor the signal. When i tugged on the wire, just a bit, it separated, and pulled away.

Once again, this site has saved me hours of searching, and a simple solution to what seemed a major dilema. I pulled the cover off the engine harness(at the firewall), and this is what I first seen. The yellow EGR wire had been repaired twice. Both times it was done wrong. It had a connector crimped tight to the dist. block and an inch long piece of brown wire crimped back into the original yellow harness wire. I guess that explains the PO401 I got in the past. I changed the EGR,it came back and once again I changed the EGR. After fixing this wire, I realized I wasted $140 on a new one, and $25 on this used one. It took over the course of a year before this wire problem caused any issues. The black wire that goes to the camahaft position sensor,(which is also new) was actually broke at the block as well, causing the PO341 codes. I believe it was damaged while someone "repaired" the yellow wire. It definatley broke off over time because it was rubbing againt the connector. I had an extra harness layin around, as I have aquired quite a few spare parts and such since this affair began! I pulled the two pins I needed from this harness' dist. block and cut those wires out of the harness about a foot back, in case I need to repair later. This to me, just seemed easier and I spent four days under the hood last week, so I didnt change entire harness', for those wondering. A few tools, some connectors the wires to be replaced, some good lighting and it was simple. I spliced the wires using inline connectors,wrapped them individually, and finished them each with heat shrink tubing in there corresponding colors. This is must removed or slid back in or on the harness' dist. block, to remove the wire and pins/connectors. Back together, no SES, no stored or pending DTC's and car runs amazingly again. You can barely see the repairs and the new parts certainly couldnt hurt anything lol. I put the cover back on, and its all tucked away neatly. Im glad this didnt rear its ugly head in the middle of an upstate new york winter! Hopin to purchase a 99 Riv cple weeks, if not then This one will be put up and I will have to find a beater Riv!

Glad you finally found the problem. Your fix was *very* well done, I am glad you posted pictures, thanks.

Albertj

Congrats and thanks for the pics Craig.

Wow! Job done! I would solder those wires though.

Sounds crazy, but I had fun doing it, I needed a good challenge, and its kept me very familiar with my car. Not that I need any more challenges, but I think after the shocks and struts I will be able to move forward with my engine build. Lots of pix for sure!

when you say solder, do you mean the ends of the connections, or the two wires together? I dont wanna do this again because it broke, but if soldering them would help, I will. Please clarify if you would, as Im unfamiliar with the technique for splicing wiring with solder. Thank you.

knuckled1 wrote:

when you say solder, do you mean the ends of the connections, or the two wires together? I dont wanna do this again because it broke, but if soldering them would help, I will. Please clarify if you would, as Im unfamiliar with the technique for splicing wiring with solder. Thank you.

It's one or the other. Always crimp only between a wire and a new terminal pin. To connect wire ends together to extend them or whatever, it's much better to solder and use heat-shrink insulators. Those crimp on butt splice deals are pretty notorious for getting loose or letting go.

WOW I feel like a jack ass. my SES light has been on and off for the past year.
I bought the kit online for using my lap top to read the codes...
long story short it didn't work. so after several attempts on ebay
I finally landed an Actron CP9185 auto scanner. and after doing
the coolant drain, flush, water pump and thermostat then refill.
I got to read the Manuel then tried it out... Now I read the posts
about doing the water pump and while its all apart go ahead and
change the camshaft position sensor. but I figured hell if it aint broke don't fix it
right.... well here it comes! are you ready? The scanner said code p0341
the camshaft position sensor fault. Damn am I a Jack Ass! I should have
just changed it when it was all apart! but no! I had to learn the hard way...