Gabe32

i have a 2000 engine and my tone ring exploded and took out my crank sensor. Well i began to look around on my engine and I noticed that I also have a cam sensor. The cam gear doesn't have a tone ring on it, so why is the cam sensor there? I would rather use the cam sensor than the crank sensor. I have a cam gear with the tone ring on it. I just want to know if anyone has swapped this over and if all i have to do is put the cam tone ring gear on my cam?

george7941

Sorry, I don't know the answer to your question. Usually Crank Sensor signal is what most engine control modules use to run the engine and the Cam Sensor signal is only used as a check on the Crank signal and codes are set if the two signals do not match up. I think I have a defective Cam sensor and am going to change it. I had a post here before trying to get some info on the Cam sensor and had no replies, so I don't know if anybody here knows.

Truckman

It's somewhere around 2001.5-2002 they did away with the crank sensor and ran everything off the cam sensor,, SO maybe if you get a wiring harness and a ECM from a 2001.5-2002 it might work,,Might need to change Map sensor too..


Good luck

Gabe32

I know what it does and all that. My question is why does my engine have both of them? The cam sensor, right now, is not doing anything and I wondered if I just tapped into that if it would work. It is the same hall effect sensor, so why does it matter where it picks the signal up at? You are right that the 01.5 and up just use the cam sensor, so why can't I?

badme

Cam turns at half the speed of the crankshaft, so at the very least case you would have to update the software in the ecm.

bent valves

If the crank sensor is broken the ECM will use the VP44 pump speed signal as a backup to keep the engine running. I seem to remember that if the engine is shut down with a bad crank sensor it will not restart. I think the change to remove the crank sensor might be involved and require many changes in the ECM.

J BODY

Your going to be dropping the pan for cleanup so why don't just install a new tone ring? You can do that in vehicle. It's not fun, but it can be done.

Gabe32

Ok, i have been trying to research this some and this is what I found out:
1. the cam rotates 180 to the cranks 360.
2. the crank tone ring has about 35 gaps in it.
3. the cam tone ring has 58 gaps in it.

the cam is not quite double but I wonder if it would work?
I am trying to do this without ecm changes because I know that causes conflict with alot of other in cab functions ( I know first hand).
I am thinking about taking my crank sensor wiring and running it to the cam sensor.

The reason why I don't just want to replace the crank tone ring is because it is a known issue with these engines and it would more than likely happen again. My tone ring didn't work loose, it just broke in like 4 pieces. Next time it happens, I might not be so lucky.

badme

Like I said, the cam turns half as fast as the crankshaft. The crankshaft has 35 gaps, 35x2=70, cam has 58 gaps it needs 70 to work. The crank sensor tone ring also has one big gap that tells the ecm that it is on TDC. That is why it is 35 gaps instead of 36, 36=360 degrees. The ecm wants to see 35 gaps not 58 or 70. Sounds like you are opening a big can of worms.

Gabe32

I know exactly what you are saying, I just wanted an alternative. I just don't want it to happen again. I guess I will just get another tone ring tomorrow. thanks for the help

99fl70

This is an informative thread. My firs time here. I have a 99FL70 that lost the tone ring and cratered the motor. I put a ISB from an 01 dodge in it and found out about the tone ring. The dodge crank is not cut for the tone ring. The engine starts and runs fine at idle and first and second gears. Gutless beyond that. I was told it is running in limp home mode. Where this is going is I have a tone ring and plan to make a spacer and mount it to the balancer and have it external.

How do I determine TDC to mount the tone ring with the blank space there? I will also make a bracket for the crank position sensor to point at the relocated tone ring. How far can it be from the tone ring?

Thanks,

Doug

99fl70

The rest of the story. I obviously used the computer from the freightliner engine. I moved all the sensors from that motor as well. Had I known, I would have swapped cranks while both motors were out.

Doug

Gabe32

the 98 to 00 cummins used tone rings on the crank. The crank is machined to accept that tone ring. I just replaced mine last night. Some 00's and up to 02 used a cam tone ring which is way better in my opinion. As far as determining where to put the TDC for the tone ring. I am not sure.

79warlock

The cam sensor is only used for diagnositic purposes. The crankshaft tone ring gaqp doesn't point at the crank sensor at tdc, it's 60 degrees away.

99fl70

60 degrees clockwise or counter clockwise? Does anyone know if it matters, Is it just used for RPM?