I have 2002 Monaco Diplomat Cummins ISC 330 HP. Stop engine light came on and limped to Cummins Service Center. Check showed was the oil pressure switch that goes to control box and of course engine immediately detuned. After looking at it they tried to order replacement but say original not available. Sitting in their shop for over two months while fiddle around. Service manager said would try to adapt new switch to existing wiring but still no report. Any suggestions as to how to adapt new switch to old wiring or where a replacement to match old could be found? TIA Tony West
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The original oil pressure sensor communicated with the ECM and reported actual pressure, probably 19 psi at idle and up to ~70 psi highway speeds warm. If you had an engine monitoring system it would show the actual pressure.
Cummins changed this to a switch, basically if the oil pressure is good the ECM sees 55 psi. If you using a engine monitoring system it would show 55 psi. The change also requires a harness and new sensor, and a change to the ECM programming. All for ~$450.
The original sensor is obsolete, can't find it using the original number.
You could try and get the shop to install this part. Cummins 4921511
This is for a 5.9 but there are reports that it will work. I bought one and carry as a spare.
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Jim J
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi
Cummins should know better than anyone what is needed, available etc.
The attached pic is from 2002 Diplomat Owners manual.
Your coach may have the attached Cummins "Service Bulletin 3377931 - Oil Pressure Switch Installation" done that jacwjames mentioned.
It should be easy to tell if that's done. If the oil pressure gage moves with RPM (& affected with oil temp), you have a sensor. If the gage is always in the same spot when engine is running, you have a switch.
Or if you have access, you can visually tell which one it is as they are so different.
If I recall, there have been several alternatives mentioned that work for both sensors and switches.
"Cummins should know better than anyone what is needed, available etc."
I have only found the guys that have been at Cummins for a lot of years or have left and work somewhere else to know what they are doing. That's why I do my best not to deal with them.
Tim
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Full Time 2000 Dynasty Regent FD, 8.3, Banks Turbo, 5" Diameter Exhaust, 475 HP 1425 Torque, FASS system, towing 05 Pilot 1500 Watts solar 800ah lithium & E-Bike
Cummins should know better than anyone what is needed, available etc.
The attached pic is from 2002 Diplomat Owners manual.
Your coach may have the attached Cummins "Service Bulletin 3377931 - Oil Pressure Switch Installation" done that jacwjames mentioned.
It should be easy to tell if that's done. If the oil pressure gage moves with RPM (& affected with oil temp), you have a sensor. If the gage is always in the same spot when engine is running, you have a switch.
Or if you have access, you can visually tell which one it is as they are so different.
If I recall, there have been several alternatives mentioned that work for both sensors and switches.
I am aware of this. I helped another Monaco owner a couple years ago. His rig would start but derate with CEL on. I recommended a bunch of troubleshooting and narrowed it down to the oil pressure sensor. He was able to drive to the nearest Cummins shop and they installed the 55psi switch with the new wiring harness. Cost $450. So yes it is what they recommend.
But for people who want to know what the actual oil pressure is it may not be a viable option. It wouldn't for me, so I bought the sensor I posted the number off to carry as a spare.
Monaco did install their own sensors that feed the dash gauges. This includes the engine & transmission temp, and an oil pressure gauge. The picture that you posted is the Monaco installed oil pressure sensor. IMHO not nearly as accurate or responsive as the Cummins sensor that communicates to the ECM.
The part that I posted can be installed in probably 5 minutes. What's the harm in them trying it.
__________________
Jim J
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi
I am aware of this. I helped another Monaco owner a couple years ago. His rig would start but derate with CEL on. I recommended a bunch of troubleshooting and narrowed it down to the oil pressure sensor. He was able to drive to the nearest Cummins shop and they installed the 55psi switch with the new wiring harness. Cost $450. So yes it is what they recommend.
But for people who want to know what the actual oil pressure is it may not be a viable option. It wouldn't for me, so I bought the sensor I posted the number off to carry as a spare.
Monaco did install their own sensors that feed the dash gauges. This includes the engine & transmission temp, and an oil pressure gauge. The picture that you posted is the Monaco installed oil pressure sensor. IMHO not nearly as accurate or responsive as the Cummins sensor that communicates to the ECM.
The part that I posted can be installed in probably 5 minutes. What's the harm in them trying it.
Is 4921511 an actual sensor as it sure looks to me like a switch.
If it is in fact a sensor, do you know if it matches the resistance values or whatever the ECM in your coach is looking for for various oil pressures?
None of the web searches say anything about any of that other than it fits Dodge Ram 5.9L 1998 to 2001.
There are reasons why they specify a vehicle, year etc. on a part like this (thread/sealing, connector, output etc).
Is 4921511 an actual sensor as it sure looks to me like a switch.
If it is in fact a sensor, do you know if it matches the resistance values or whatever the ECM in your coach is looking for for various oil pressures?
None of the web searches say anything about any of that other than it fits Dodge Ram 5.9L 1998 to 2001.
There are reasons why they specify a vehicle, year etc. on a part like this (thread/sealing, connector, output etc).
There have been several discussions on IRV2 about this. I posed this question on one of them. Someone posted that they did buy the sensor and swapped it out and it did work.
I did buy one and will carry as spare. I have not installed so can't confirm if it would work. But if I get a fault code showing this may be a problem it wouldn't take long to install and I'd either be back on the road or limping to the nearest Cummins dealer.
One issue that I have is that when I bought my coach in 2008 the dash oil pressure gauge was pegged out. It goes to zero when the engine is off but when running it shows high oil pressure. At the time I took it to the nearest Cummins shop for a complete inspection and service, I requested they look at this. They came back and said the ECM was reading the right pressure but the dash sender had been hooked up wrong (or some other issue) and that the gauge would have to be replaced for it to show the correct pressure. So I can't rely on the dash gauge.
But since I've got the Silverleaf I know the pressures are good with the current sensor. If this sensor craps out and I am forced to go with the one listed in the service bulletin my Silverleaf would read 55 psi all the time or zero, which I think is useless.
__________________
Jim J
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi
There have been several discussions on IRV2 about this. I posed this question on one of them. Someone posted that they did buy the sensor and swapped it out and it did work.
I did buy one and will carry as spare. I have not installed so can't confirm if it would work. But if I get a fault code showing this may be a problem it wouldn't take long to install and I'd either be back on the road or limping to the nearest Cummins dealer. ...
I'm real curious as I used to work on these systems in the auto industry in the 90s. The switches we used were just about identical to 4921511. Nothing but a diaphragm, spring and contacts. So it was either on or off at around 5-7 psi.
Now I need to go buy one so I can open it up and see what's inside.....
The actual sensors were more like vito.a's post above. They had a linkage to a rheostat type setup. The last real sensors were phased out by mid-90s.
After that just switches, whether for a gage or a warning light.
I'm real curious as I used to work on these systems in the auto industry in the 90s. The switches we used were just about identical to 4921511. Nothing but a diaphragm, spring and contacts. So it was either on or off at around 5-7 psi.
Now I need to go buy one so I can open it up and see what's inside.....
The actual sensors were more like vito.a's post above. They had a linkage to a rheostat type setup. The last real sensors were phased out by mid-90s.
After that just switches, whether for a gage or a warning light.
The VDO sensor it one that Monaco installs to hook up to the dash gauge.
Cummins have their own sensors that feed the ECM.
Completely different beasts but when the Cummins sensors fails it results in a CEL, engine derate, and/or shutdown.
__________________
Jim J
2002 Monaco Windsor 38 PKD Cummins ISC 350 8.3L
2005 Jeep Grand Cherokee w/5.7 Hemi
Cummins should know better than anyone what is needed, available etc.
The attached pic is from 2002 Diplomat Owners manual.
Your coach may have the attached Cummins "Service Bulletin 3377931 - Oil Pressure Switch Installation" done that jacwjames mentioned.
It should be easy to tell if that's done. If the oil pressure gage moves with RPM (& affected with oil temp), you have a sensor. If the gage is always in the same spot when engine is running, you have a switch.
Or if you have access, you can visually tell which one it is as they are so different.
If I recall, there have been several alternatives mentioned that work for both sensors and switches.
The picture you show looks like the oil pressure switch on 1980’s and 90’s Porsche’s. My suspicion is many oil switches will work
[QUOTE=bpu699;6283307]The picture you show looks like the oil pressure switch on 1980’s and 90’s Porsche’s. My suspicion is many oil switches will work
No, the switch or sender has to match the system. We used both normally closed (NC-contacts open with good pressure) and normally open (NO-contacts close with pressure) switches. The NC switches were used for vehicles with a warning light and normally open for vehicles with a gage.
Then there are many other reasons not every switch or sensor works as already touched in this discussion earlier (thead size, sealing strategy, connector compatibility, output etc).
These switches are proportional, not on/off:
Just to keep the terminology straight, a switch is just that, an on-off switch like a light switch in your house. A sensor or sender is proportional. Just because internet if full of these mislabeled parts, does not make it right.
The picture you show looks like the oil pressure switch on 1980’s and 90’s Porsche’s. My suspicion is many oil switches will work
No, the switch or sender has to match the system. We used both normally closed (NC-contacts open with good pressure) and normally open (NO-contacts close with pressure) switches. The NC switches were used for vehicles with a warning light and normally open for vehicles with a gage.
Then there are many other reasons not every switch or sensor works as already touched in this discussion earlier (thead size, sealing strategy, connector compatibility, output etc).
These switches are proportional, not on/off:
Just to keep the terminology straight, a switch is just that, an on-off switch like a light switch in your house. A sensor or sender is proportional. Just because internet if full of these mislabeled parts, does not make it right.
If I understand the posts above, the original part was a SENDER. Now updated to a SWITCH that isnt available.
My suggestion was to go back to the SENDER, as that was working. Oil pressure SENDERS do not need to be specific to a vehicle, they simply need to have the same threads and OHM range. Threads can be adapted.
Often you just need to find a sender that matches the OHM range, to use as a bandaid, until the appropriate sender is available. Clearly its "doable" as the guys mechanic had the same thoughts.
Problem With Oil Pressure Sender
Linear Mode
