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2001 coupe , manual trans. I'm finishing up a cam upgrade. After a couple short runs I got 2 codes. Cam sensor circuit low voltage (code PO342) and loss of communication undetermined (BO- RAF- U1000).
After they were cleared only the low voltage returned, not every time. Couple days ago they both returned as soon as I turned the Key on. I'm looking for a wiring diagram with wire colors. Can't seem to find anything to my specific year-model. I pulled the sensor out yesterday and this is what I found.... When I pulled on it the sensor it came out with no resistance. The O ring was hard and shrunk up tight on the shaft. The shaft was full of oil, dirt and grime. The small holes at the bottom were packed full. Couldn't see them. It looked like it has been soaked in oil and rubbed in fine dirt and dust. It was allowing all this from inside and outside the engine for many years. Also The connector rubber was damaged slightly and was letting in years of oil, dirt, etc.I have a new sensor, but would like to run some test to make sure the wiring is ok. I disconnected the battery and with the old sensor out,, is there anyway to bench test it??
Thanks, and have a great New Years...
mike v
Last edited by mike venth; Dec 30, 2021 at 12:26 PM.
Picture below is from my 2001 FSM…CMP is a 3 wire Hall Effect Sensor…12 volt reference, CMP signal and a low reference (ground)….Key on you should have 12 volts on the 12 volt ref…with test light connected to battery positive test light should light when probing low reference…as far as the signal wire I would check for a short to ground on the signal wire…disconnect the C1 PCM connector and the CMP connector…put your ohm meter on the highest resistance scale…place 1 lead of ohm meter on the brown/white wire at the sensor and other lead of ohm meter on a clean ground on the body…ohm meter should read OL or whatever your ohm meter shows when the leads are held apart…this can also be a bad sensor too !!
C5Diag,,, Thank you for the information. This will be a great help. I will let you know how it turns out. Have a big 2022 year..
mike v
ps: I have a place in Daytona Beach where I spend the cold months. Running late this year. The Vette is taking more time than I expected,,,
Got a late start on it....LOL
C5Diag,,, Thank you for the information. This will be a great help. I will let you know how it turns out. Have a big 2022 year..
mike v
ps: I have a place in Daytona Beach where I spend the cold months. Running late this year. The Vette is taking more time than I expected,,,
Got a late start on it....LOL
No problem !!…this “low voltage” DTC means that the PCM is seeing low voltage on that signal wire…the PCM should see the signal go from 12 volts to 0 volts and keeps repeating as the sensor passes over the single reluctor tooth…it’s a 1X !!…also HIGHLY recommend an OEM sensor and not an aftermarket..I just replaced 4 O2 sensors on the car yesterday (1 upstream was dead) and both upstreams were no good out of the box…4 Delphi O2’s from Rock Auto costing $200.00 so I’ll be sending all of them back..the good upstream sensor on the right side was very difficult to remove and looks like the threads were wiped so looking for a tap and then heading to the local Chevy dealer to see if they have some and I will check them with a heat gun and DVOM before installation !!..HAPPY NEW YEAR !!…if you’re ever in the area stop by !!
Thanks C5Diag,,,, Some years back I went purchase a new set of Tap & dies...I didn't realize until a couple days later what I picked up was a set
of thread chasers. There smaller in size , so they fit in tight places. The other thing is -- They remove less metal, but do a great job of refreshing the
threads. I bought a set the covers all 3 types of threads. Pipe Threads,,,Metric Threads,,, and good ole American..
They work great,,, so I hope they will help with your fix.
mike v
Also::: I talked to Bill Curlee and what we decided was this----Because the sender was completely covered with oil, dirt, grease and grime,even at the plug because of the failed
o-ring on the shaft, and the seal at the connector, could be the problem. I did Bill's push & pull test and tightened up the female ends of the connector, and put in the new sensor. Already had it--SO might as well us it.. Hopefully be back together by tonight....
I will keep ya'll informed of my progress..............................
Last edited by mike venth; Dec 31, 2021 at 01:25 PM.
That would be kool,,,,
This is what I'm doing- along with new sensor,,,,,,,,,
New cam, ported /polished heads, ls7GM racing lifters, roller rockers, pushrods, new injectors, headers, tune and all the kool things that go
with them...
mike v
Just a quick note to let everyone know that the sensor change worked. No more codes. Also would like to thank C5 Diag and Bill Curlee.
Happy New Year Guys......
mike v
cam sensor info please
