The oil pressure gauge on our coach is faulty/ Cruise issues?

[Bob Disney]

The Aladdin oil pressure gauge is faulty
Also the cruise control stopped working about the same time
I'm looking to replace the sensor for the oil gauge
the dash gauge has been consistent
does this sensor run through the ECM and could this be what killed the cruise control?

[Richard Davis]

Bob
There are two oil pressure sending units mounted on the passenger side of the C9 about mid point.  One of them is for the dash gauge and the other is for the ECM.  The C9 is a HEUI motor that will simply not run without adequate oil pressure.  I believe the Aladdin system uses the signal on the data bus from the ECM.  You may have a failed sending unit, or there may be a failed electrical connection at the sending unit.  You might try disconnecting the sender and cleaning the connectors with an antioxidant to see if that cures the issue.  Sadly, the senders are in a difficult location to conveniently access and replace.  Good luck.
Richard   

[Eric Maclean]

Bob
The Aladdin system reads serial stream data from the engine ECM which gets its oil pressure reading from its own oil pressure sensor mounted on the passenger side of your engine.
The following is a link to a video which will help your identify the sensors.

https://youtu.be/Bn33Jf0wWY4?si=e2wOOTlfxFDjk5P5


The cruise on these coaches are a function of the engine ECM and can be disabled if there is a fault code present in the ECM
the engine break if turned on will disable the cruise as will an active  brake light circuit.
First place to start is by checking the ECM for active fault codes also a good time to look at what the ECM sees for oil pressure.
low or no oil pressure reading may cause the ECM to create and many disable cruise as well.
We know this engine must have oil pressure or the HEUI system would not create enough pressure to start the engine
Hope this helps
Eric

[Bob Disney]

I have a sensor coming
figured as old as the coach is it wouldn't hurt replacing it
it mostly showed double pressure compared to what the dash was showing 
we will see what happens when replaced

[Bob Disney]

I called CAT here local to see if they had a oil pressure sensor on hand, they did at $256.00
I overnighted the oil pressure sensor up out of Florida from a company called Advance truck parts for about half the cost including $70.29 in shipping
Not to bad to install, I removed the crankcase breather to access it, hard to see to well but was able to feel it,
it did fix the pressure readout on the Aladdin
I will get back to you if this helps with the cruise control
Also when the cruise is working, it works in tandem with the exhaust brake, on the big roiling plains out west it will downshift and engages down hills, then back on the throttle up the other side.

[Bob Disney]

Didn't fix the cruise control
What does it take to check the ECM?
Is this something that we could have checked at Quartzite?

[Steve Huber Co-Admin]

Bob,
What is exactly happening with your cruise control; not engaging at all, dropping out of CC unexpectedly, etc. ? Does the exhaust brake mode have any effect? When selecting CC does the Aladdin display indicate it is on?
Steve

[Eric Maclean]

Bob
David Atherton should be at the Quartzite Rally you could have him check out your cruise there he has a scan tool with Cat ET  software to check for fault codes and can do some Bi directional communication to check functionality of the cruise .
It might be a good opportunity to have Dave print you a copy of your ECM configuration ( what we call a clone ) so if ever your ECM fails your have the proper configuration to set up the new ECM.
Your problem is not likely in the ECM . I is likely a switch or wiring ,these coaches are set up with a couple of relays for brake lights and engine brake lights check first that your brake light circuit is functional
Then you may have to pin out the cruise inputs at the ECM to make sure the switching signal is getting to it.
There is a large bulkhead connector at the electrical bay which can be problematic check the connections there .
Page 53 of the 2005 Monetary wiring diagrams shows the cruise control wiring with connections .

Good luck and have a great time at Quartzite
Eric

[Steve Huber Co-Admin]

Eric,
The reason for my questions is that it could be something as simple as a bad clockspring or faulty connector in the steering column since the CC controls are in the steering wheel.
Steve

[Eric Maclean]

Yes the clock spring is a good possibility for a failure point if it has steering wheel controls .

[Steve Huber Co-Admin]

Bob,
Pg 6 of the 06 Monterey wiring diagrams has a readable version of the CC circuit.
Steve

[Bob Disney]

The Cruise just does not come on
It had always worked, whether the exhaust brake was on or not
The controls are on the steering wheel but seem un affective 
When I had a shop look into it the said that it would show as engaged but would disengage when put in gear (or something like that)
I don't know if they had the capacity to check the ECM
I really miss the cruise control

[Fred Brooks]

    Bob,
  I would probably start with the "Smart wheel" and control unit. Your clock spring is 19 years old and could have issues with the contact ring internally. You could also check the connector plug behind the column cover near where the column articulates. You can find the trouble-shooting guide in our library in "coach assist" for the Smart wheel. From the Beaver Amb home page: > Technical >Coach assist > scroll down to Smart wheel to the trouble shooting guide. Fred

[Bob Disney]

I watched a utube video and it appears the clock spring is relatively easy to replace if that is the problem
I think I would like to eliminate the ECM first
Can the ECM be tested without  taking it off the engine?
 

[Steve Huber Co-Admin]

Bob,
Strongly suggest you do not have anyone but a CAT dealer try to diagnose the ECM.
Steve