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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: John Morales on September 12, 2019, 05:47:37 pm

Title: Engine Speed Sensor
Post by: John Morales on September 12, 2019, 05:47:37 pm
Was on the road with no problems.  Stopped at a Walmart for a couple of hours.  Started up and I got a Engine Speed Sensor Warning.  Using the BlueFire device I looked up the fault code and it read 190-10 Warning Description: Engine-Engine Speed Sensor.  Abnormal Rate Of Change.  Since it was just a check engine light I drove 16 miles to our campground, turned off the coach to register,  started the coach and the warning was gone.  Just wondering if someone knows where the engine speed sensor is located so I can check the connections.  My wife said that when we were parked at Costco for the night she heard something like a mouse in the engine compartment.  We were parked close to a farmers field where it looked like they had just turned over the soil.  Just need to know where is the Engine Speed Sensor Located.

John M.
Title: Re: Engine Speed Sensor
Post by: John Morales on September 12, 2019, 06:25:14 pm
Well looking at the Diagnostic Fault Codes For Cummins Engines it states it is the magnetic pickup.  Attached is a screenshot of the list of codes.
Title: Re: Engine Speed Sensor
Post by: John44 on September 12, 2019, 08:35:22 pm
Taking a guess it would be on the housing of the engine to count the teeth on the flywheel.
Title: Re: Engine Speed Sensor
Post by: Olde English on September 12, 2019, 09:10:46 pm
I would start my search close to the end of the crank shaft, near the belt pulley. IMHO
Title: Re: Engine Speed Sensor
Post by: DavidS on September 12, 2019, 09:18:49 pm
Here is what it looks like
Title: Re: Engine Speed Sensor
Post by: John Morales on September 13, 2019, 11:58:34 am
Thanks everyone for the help and ideas.  It poured all night and as soon as it dries up a little we will go hunting for the sensor.
John M.
Title: Re: Engine Speed Sensor
Post by: Mark D on September 13, 2019, 09:38:26 pm
My coach sat on a consignment lot for a long time.  It registered this code before a test drive.  When we had it dyno tested cummins cleared the code and we've never seen it again.  But the cam sensor is a known and inexpensive issue.
Title: Re: Engine Speed Sensor
Post by: John Morales on September 14, 2019, 02:08:29 pm
Well it was a beautiful day today so I decided to look into the sensor issue.  I was able to receive some guidance on the location of the sensor. It is in a very tight and difficult position in the front of the engine on the drivers side.  If you look at my first picture below you can get an idea of where the engine position sensor is located.  The next picture is the air conditioner pump, idler pulley and water pump.  If you look under the air conditioner through where the idler pulley location you will see a plug with 4 wires.  Follow the harness towards the engine to the sensor.  It seems it is screwed behind the the water pump just above the pump.  Tight spot to get into.  I think if I had to remove it I could use a short handle service wrench.  No room to stick your head in there.  Above is the large intake.  Below is the exhaust.  Air conditioner pump is in the way.  A PIA to get to.  I believe I can do it blindly with the service wrench.  Part can be found on EBay for about $20 and the number is 4326596.

In the process of locating the sensor and plug, I decided to pull the plug apart, clean it and apply some dielectric grease.  Upon looking at the plug it felt very loose.  When I went to start pulling it apart, it separated very easily.  Looked at the male end and found the plug lock was broken and not keeping the connection tight.  I'm going to clean it up and put a zip tie on the connector to keep the connector halves from pulling apart. I'm hoping this will solve the issue.

A big thanks to JC hotonthetrail on this forum for walking me through the location on the phone. He was a big help and very informative.  Thanks to everyone else for your comments and private messages.  We will let you know if this solves the problem.

John and Carmen
Title: Re: Engine Speed Sensor
Post by: DavidS on September 14, 2019, 02:16:47 pm
I was going to say dbl. check the connection. When I was looking at parts for you I read a little and it looks like a few of the issues was the connection.

Hope you fixed it!!
Title: Re: Engine Speed Sensor
Post by: John Morales on September 14, 2019, 02:55:56 pm
I cleaned and put the connector together and still getting the check engine light.  Question, do I have to clear the code for the check engine light to go off? Can I disconnect the chassis batteries to clear the code?

Thanks in advance, John M.
Title: Re: Engine Speed Sensor
Post by: Caflashbob on September 14, 2019, 06:41:27 pm
The sensor part shorts out inside the potting material.  Oil gets in the plastic.  There are two sensors in the unit.

Both will short internally finally.

If they are bad you may be able to hear the engine misfiring at idle.  Erratic pulses.

The replacement unit is solid metal on the end.  No potting.

The ism added a crank position sensor to the cam sensor for backup.

If both of your sensors fail it flat bed time.  Sounds like one is out already
Title: Re: Engine Speed Sensor
Post by: John Morales on September 14, 2019, 10:37:16 pm
A good video explanation about the engine position sensor.
John M.

camsensor - YouTube (https://youtu.be/L1kDN8sohPA)
Title: Re: Engine Speed Sensor
Post by: John Morales on September 15, 2019, 05:36:23 pm
Sensor update.  Drove 3 hours from my campsite and stopped to fill up.  When I went to start the check engine light was off.  Hoping it reset itself for good after fixing the connector plug.  Either way I ordered the sensor from Cummins. According to the video I posted, they should be changed every five years.  EBay had the sensor for $20 but I didn't want to take a chance on getting a cheap knockoff from China.  I wanted the Genuine Cummins Sensor.
John and Carmen

Amazon.com: 4326596 Cam Sensor For All Cummins L10, M11, N14 Engines (Celect... (https://www.amazon.com/4326596-Sensor-Cummins-Engines-CelectPlus/dp/B01452UCAQ)
Title: Re: Engine Speed Sensor
Post by: Bill and Marsha on September 15, 2019, 11:29:31 pm
Good work John, thanks for sharing, believe I'll order one as well.
Title: Re: Engine Speed Sensor
Post by: John Morales on September 16, 2019, 12:13:52 pm
Well after unloading this morning we started the coach and we got the dreaded check engine light again.  We have the sensor on order.  We will change it as soon as it arrives.  If that doesn't  work then it is off to Cummins.
To be continued....🤔🤨🤬
John and Carmen
Title: Re: Engine Speed Sensor
Post by: Journey, Roam, Explore on September 16, 2019, 09:22:52 pm
Thanks John for the pics and the links. A good proper post of what is wrong, great documentation, and links to the part to fix it. Wish every post was like this.
Title: Re: Engine Speed Sensor
Post by: Mark D on September 17, 2019, 07:14:50 pm
Another good video which also discusses what the socket size of the sensor is and how people grind out a slot to fit the socket around the wiring.  I believe he also said it's the same size as an o2 sensor socket.
https://www.youtube.com/watch?v=oCxojfhkYBk

Does anyone know if you have 1 of 2 internal cam sensors failed will you get a yellow check engine?
Title: Re: Engine Speed Sensor
Post by: Pamela & Mike on September 17, 2019, 07:47:47 pm
Does anyone know if you have 1 of 2 internal cam sensors failed will you get a yellow check engine?

Ours don't.  When the primary went out and it swapped to the back up the engine developed a slight miss.

Mike
Title: Re: Engine Speed Sensor
Post by: Mark D on September 17, 2019, 08:31:13 pm
Ours don't.  When the primary went out and it swapped to the back up the engine developed a slight miss.

Mike

Interesting, I'll check out if I have any codes set on mine.  I can hear it miss every now and then.  Maybe once every 5-10 seconds and only at idle.  Any fix where I don't have to crawl around on the ground fighting wasps is fine with me
Title: Re: Engine Speed Sensor
Post by: Pamela & Mike on September 17, 2019, 09:09:07 pm
1. I'll check out if I have any codes set on mine. 
2. I can hear it miss every now and then. Maybe once every 5-10 seconds and only at idle. 
3. Any fix where I don't have to crawl around on the ground fighting wasps is fine with me

Mark,
1. You should have that on a '99
2. Same symptoms as ours.
3. Can't guarantee that.

Mike
Title: Re: Engine Speed Sensor
Post by: John Morales on September 20, 2019, 04:00:43 pm
I received my sensor today.  My dilemma is removing and replacing the sensor.  Searching the internet, auto part and truck parts stores for the socket was unsuccessful.  The only sensor socket I found was 7/8".  The Cummins Engine Speed Sensor is 11/16".  On the internet I found that Cummins has a socket for that sensor at $118 with the shipping included.  I'm going to try and use a crows foot and see how it works.
To be continued,  John M.

https://www.apexinds.com/tools/M20123.html
Title: Re: Engine Speed Sensor
Post by: Protech Racing on September 20, 2019, 04:03:00 pm
Maybe you can knock the top of the sensor off and use a standard socket to remove it .
Title: Re: Engine Speed Sensor
Post by: DavidS on September 20, 2019, 04:04:47 pm
Maybe a ratchet wrench?
Title: Re: Engine Speed Sensor
Post by: Super8mm on September 20, 2019, 04:18:19 pm
Almost looks like you can take a 11/16 spark plug wrench and grind out the side of it and if need it longer cut the top off and weld a 1/2 or 3/4 pipe on it and drill a hole and make it a T handle
Title: Re: Engine Speed Sensor
Post by: John Morales on September 20, 2019, 05:30:04 pm
I'm a toolmaker by trade. Making the tool would have been easy.  The problem is I don't have access to tools and equipment anymore.  Looking to use the Proto Crowfoot Socket Wrench.  It should work.
John M.
Title: Re: Engine Speed Sensor
Post by: Pamela & Mike on September 20, 2019, 05:52:16 pm
John,

That and a 4" extension will work just fine. 

Mike

Title: Re: Engine Speed Sensor
Post by: John Morales on September 20, 2019, 07:41:25 pm
Mike, I agree.  I have a 3/8 palm ratchet I can use in case space is limited.  We will keep the updates coming.  Thanks everyone, John M.
Title: Re: Engine Speed Sensor
Post by: John Morales on October 09, 2019, 04:27:03 pm
Finally!  I finally got a break in my schedule and the weather to change the Engine Speed Sensor. 
1.  I loosened the AC belt tensioner, removed the belt and moved the tensioner up out of the way.  All of the work was done through the area under the AC compressor.
2.  Unplugged the old sensor.
3.  I used the my 3/8" ratchet and the crows foot socket to break the sensor loose.  It didn't take much to loosen it.  The rest of the removal was done by hand.
4.  Lubricated the o-ring on the old sensor and installed it by hand until I couldn't turn it any more, then used the ratchet to tighten it up the rest of the way.  Was concerned about over tightening because of the o-ring.  Turned it till I was met with some resistance and then I stopped.
5.  Started the engine and no check engine light.  Started it a few times and no check engine light.
6.  Replaced the AC belt and tensioner and job is done.

Strange Thing:  My odometer would always flicker and I could never tell my mileage.  With the new sensor my odometer is working.

Attached are some pictures.  Easy job, John M
Title: Re: Engine Speed Sensor
Post by: rbark on October 09, 2019, 07:45:55 pm
Great write up  with pictures John!
Title: Re: Engine Speed Sensor
Post by: Mark D on October 16, 2019, 08:18:04 am
Strange Thing:  My odometer would always flicker and I could never tell my mileage.  With the new sensor my odometer is working.

This is probably unrelated.  I find that my odometer comes and goes somewhat on a whim.  The next time you drive it it probably won't work again.  Needs new capacitors inside the unit to truly fix it.
Title: Re: Engine Speed Sensor
Post by: John Morales on October 16, 2019, 01:44:51 pm
Mine does the same.  We will be sending it in for repair.
John M.
Title: Re: Engine Speed Sensor
Post by: Caflashbob on October 16, 2019, 02:22:23 pm
As does mine. 
Title: Re: Engine Speed Sensor
Post by: bdale on October 16, 2019, 03:07:57 pm
Same issue.  Sometimes readable, sometimes not.
Title: Re: Engine Speed Sensor
Post by: John Morales on October 17, 2019, 04:27:36 pm
Well, I drove from Illinois to Florida and no check engine light, no issues.  The engine speed sensor solved my problem.  From all of my research on the internet,  it is recommended to change it every five years.
John M.
Title: Re: Engine Speed Sensor
Post by: bdale on October 17, 2019, 04:51:17 pm
Well, I drove from Illinois to Florida and no check engine light, no issues.  The engine speed sensor solved my problem.  From all of my research on the internet,  it is recommended to change it every five years.
John M.
Did the new sensor solve your erratic odometer, or only the check engine light issue?
Title: Re: Engine Speed Sensor
Post by: John Morales on October 17, 2019, 04:54:51 pm
No, only the check engine light.  Odometer is still wack-o 🤪.  Going to send it in for repair.
John M.
Title: Re: Engine Speed Sensor
Post by: bdale on October 17, 2019, 05:09:08 pm
That makes sense.  I was wondering how they could be related.  Turns out they're not.  Thx.
Title: Re: Engine Speed Sensor
Post by: Caflashbob on October 17, 2019, 10:09:41 pm
Cam position sensor as far as I know.