Engine position sensor
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Engine position sensor
My car just quit
2001 C5 mn6.
code is P0335, crank position sensor.
is it on the harmonic balancer area?
never had to change one.
is it just unscrew the old one and screw-on a new one with one connector?
2001 C5 mn6.
code is P0335, crank position sensor.
is it on the harmonic balancer area?
never had to change one.
is it just unscrew the old one and screw-on a new one with one connector?
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
P0335
Thanks guys
i just did clutch last weekend with rear main seal.
wonder if plug came out or burned on exhaust.
It hasn’t been a week yet.
I will post my findings
i just did clutch last weekend with rear main seal.
wonder if plug came out or burned on exhaust.
It hasn’t been a week yet.
I will post my findings
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Crank sensor
Got it out.
sensor appears to be rubbing on something
(like the crank)
Half the end is shaved an 1/8”.
Last weekend, i changed block plate, rear main seal.
could it have been possible to move the crank trying to get the pilot bearing out?
the thrust bearing would have kept the crank from walking.
but that’s what it looks like.
also, the engine seemed to have more power this week, a lot more horses, kinda
sensor appears to be rubbing on something
(like the crank)
Half the end is shaved an 1/8”.
Last weekend, i changed block plate, rear main seal.
could it have been possible to move the crank trying to get the pilot bearing out?
the thrust bearing would have kept the crank from walking.
but that’s what it looks like.
also, the engine seemed to have more power this week, a lot more horses, kinda
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 326
From: CA.
St. Jude Donor '13-'14-'15
After messing with the crank sensor /and or replacing it or doing major engine mods you must preform a "crank sensor relearn procedure" This will re set the crank sensor alignment It can be easily done at a shop that has a TECH 2 or someone that has either HP tuners or EFILIVE software
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,320
Likes: 3,927
From: Cape Coral, Florida
Did you replace the crank sensor ??...I don’t see how worn thrust bearing can shave an 1/8 of an inch off the sensor it that’s what happened??....the worn bearing (longitudinal movement) wouldn’t allow axial movement that would indeed shave off the end of the sensor off !!...do you have a picture of the old sensor ??
EDIT: BTW your crankshaft end play (2001) should be .0015-.0078"....I really don't think this is your problem and if you haven't replaced the sensor stay with OEM if you finally determine it is bad...and after checking the circuit...if you did have an 1/8 inch clearance between the end of the sensor and the reluctor wheel the sensor won't work...it is usually in the thousandths of an inch clearance !!...if you need help how to check the circuit electrically let me know !!...but you're a Part 135 guy...you should know this !!...LOL !!...only kidding !!
EDIT: BTW your crankshaft end play (2001) should be .0015-.0078"....I really don't think this is your problem and if you haven't replaced the sensor stay with OEM if you finally determine it is bad...and after checking the circuit...if you did have an 1/8 inch clearance between the end of the sensor and the reluctor wheel the sensor won't work...it is usually in the thousandths of an inch clearance !!...if you need help how to check the circuit electrically let me know !!...but you're a Part 135 guy...you should know this !!...LOL !!...only kidding !!
Last edited by C5 Diag; Apr 26, 2019 at 08:45 AM.
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Someone mentioned that the sensor has to touch the “wheel”. Seems to me it is a toothed wheel and therefore the sensor detects the segments as they go by.
It is basically a proximity sensor. We have them in aircraft to detect what the landing gear position is, and as a pickup for the engine RPM, and other things, they never touch the wheel, but are a few thousanths away from it.
the original sensor plastic was worn away to expose a piece of copper under the plastic
It is basically a proximity sensor. We have them in aircraft to detect what the landing gear position is, and as a pickup for the engine RPM, and other things, they never touch the wheel, but are a few thousanths away from it.
the original sensor plastic was worn away to expose a piece of copper under the plastic
Last edited by coupeguy2001; Apr 26, 2019 at 08:50 AM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,320
Likes: 3,927
From: Cape Coral, Florida
YES !!...exactly like a "prox sensor".....near/far...I am VERY familiar with these too...LOL !!...and yes, like I had mentioned they do have a very small clearance...I have changed other crank sensors (not on C-5's though) that have a "peel and stick" if you want to call it that on the end of the new sensor that gets rubbed away as the engine starts turning...that sets the correct distance from the wheel during installation. The PCM expects to see a 0-12 volt square wave....if it sees 3-12 volts...no good...if it sees 0-9 volts...no good !!....the blue trace is my 24X crank and the red is the 1X cam on my '01 !!
Last edited by C5 Diag; Apr 26, 2019 at 01:50 PM.
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Sensor
Ok,
took sensor back out.
looked fine.
put it back in.
sounds like sensor is hitting reluctor ring and sounds like it is running on 3 cylinders.
taking the new sensor box, and the old sensor to auto parts store.
going to look at another new sensor, and compare the new and old sensors to determine that somebody did not switch sensors into the right part number box.
getting hot here.
supposed to be 100 degrees.
high temps just slow me down
took sensor back out.
looked fine.
put it back in.
sounds like sensor is hitting reluctor ring and sounds like it is running on 3 cylinders.
taking the new sensor box, and the old sensor to auto parts store.
going to look at another new sensor, and compare the new and old sensors to determine that somebody did not switch sensors into the right part number box.
getting hot here.
supposed to be 100 degrees.
high temps just slow me down
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Sensor
New sensor is same length as old one.
not sure why it’s hitting.
but going to pull it apart again.
fortunately, learning curve is out of the way, and i can get it out in an hour.
wish i had a lift
not sure why it’s hitting.
but going to pull it apart again.
fortunately, learning curve is out of the way, and i can get it out in an hour.
wish i had a lift
Last edited by coupeguy2001; Apr 27, 2019 at 03:24 PM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
We talked on the phone. He had burnt wires on the connector. He fixed that and it runs but very rough. He still has contact between the sensor and reluctor wheel. I told him it should not make contact with the reluctor and there should be 0.003" - 0.005" between them. He has a data log device that he can see the crank sensor wave forms. He is going to check that out tonight. I bet the wave form is inconsistent causing the miss.
Last edited by Bill Curlee; Apr 30, 2019 at 12:50 PM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,320
Likes: 3,927
From: Cape Coral, Florida
We talked on the phone. He had burnt wires on the connector. He fixed that and it runs but very rough. He still has contact between the sensor and reluctor wheel. I told him it should not make contact with the reluctor and there should be 0.003" - 0.005" between them. He has a data log device that he can see the crank sensor wave forms. He is going to check that out tonight. I bet the wave form is inconsistent causing the miss.
Thanks for the update !!...burnt wires aren't good for anybody. I have no idea of why his new Crank Sensor (is it OEM ??) would be contacting the reluctor wheel. The gap is very important and the PCM will get confused and process the signal if it sees the amplitude either too high or too low. The amplitude limits are most likely proprietary information...I didn't know some of these data logging devices can log the CKP waveform...is it some kind of graphing meter ??....even if his CKP waveform is OK but still has a rough idle it's a good idea to do Cam-Crank correlation !!
Thread Starter
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Crank position sensor
I have had an education.
i have had the car since 2004.
it had 22K miles on it when i got it.
it has always had little minor things, but never any problem that kept me from driving it.
two weeks ago, it quit, got it towed home, and replaced crank position sensor with one from Standard Motor Products.
put it back together, it ran like crap.
i figured someone returned a bad part, got another one .
ran the same.
I finally went to the Chevy dealer and talk to a diagnostician and he said it sounds to me like it’s your map sensor is no good so I replaced the map sensor and it made no change .
I talked to an engine builder and he said those Standard Motor Products sensors are crap throw it away and go buy a GM sensor .
So I finally went and bought a GM sensor and when I put it in and started it up it ran perfect .
The moral of the story is if you’re going to replace a sensor on your engine you need a GM sensor because it was designed to talk to your computer .
i have had the car since 2004.
it had 22K miles on it when i got it.
it has always had little minor things, but never any problem that kept me from driving it.
two weeks ago, it quit, got it towed home, and replaced crank position sensor with one from Standard Motor Products.
put it back together, it ran like crap.
i figured someone returned a bad part, got another one .
ran the same.
I finally went to the Chevy dealer and talk to a diagnostician and he said it sounds to me like it’s your map sensor is no good so I replaced the map sensor and it made no change .
I talked to an engine builder and he said those Standard Motor Products sensors are crap throw it away and go buy a GM sensor .
So I finally went and bought a GM sensor and when I put it in and started it up it ran perfect .
The moral of the story is if you’re going to replace a sensor on your engine you need a GM sensor because it was designed to talk to your computer .
