ok-rver Posted July 16, 2022 Share Posted July 16, 2022 55 psi on Aladdin is constant if the engine is running. I see posts about changing out the oil pressure sensor going to the Cummins ECM. Could not find any info on if the new sensor is a switch or a variable sensor. My dash gage shows 35 psi or so hot at idle, 65 + hot at 1,500 rpms and 80-90 cold running so it has "accurate" readings. Anyone have any idea about why the ECM sensor does not vary based on actual pressure? Link to comment Share on other sites More sharing options...
OhReally Posted July 16, 2022 Share Posted July 16, 2022 This was a remedy that Cummins initiated to fix an issue where the EMS was noting an incorrect low oil pressure. You have two oil pressure sending units. One is sending the 55 psi to the EMS whenever oil pressure is there and the other sending unit sends the actual pressure to the gauge only. I know, sounds rather Micky Mouse but that's how it was redesigned. If your engine is running and/or you see the 55 psi your EMS is satisfied. -Jamie Link to comment Share on other sites More sharing options...
Idoc57 Posted July 16, 2022 Share Posted July 16, 2022 My Scan Gauge D does the same thing on my 5.9 ISB. I would like to know if anyone who has a Scan Gauge D is getting a transmission temp reading. I'm not sure if I need to start a new topic with this question or if it is close enough to the original post to be acceptable. Please just let me know Link to comment Share on other sites More sharing options...
ok-rver Posted July 16, 2022 Author Share Posted July 16, 2022 Thanks for confirming that the Cummins "fix" was to replace the sensor with basically a on/off switch that simulates the 55 psi. My water and trans temperatures thru the Aladdin are correct. Room temps b4 starting engine. Dash water gage and ECM temp track as they move up to operating temps, 180 & 160. Aladdin trans temp is below water temp most of the time, gets close when engine loaded or pac brake is working hard to slow down the MH. My dash trans temp is fixed at about 150 degrees. Working on figuring out the were the sensor is in the transmission. Link to comment Share on other sites More sharing options...
Mike in Va Posted July 16, 2022 Share Posted July 16, 2022 IDOC57 I have a 2001 HR Ambassador with the 5.9 Cummins with a the scan d. I found out the computer on my mh doesn't have the capability to send the trans temp to the scan d. I installed a temp probe on the line coming out to the trans cooler and mounted a gauge . Link to comment Share on other sites More sharing options...
jacwjames Posted July 16, 2022 Share Posted July 16, 2022 I'm fortunate in that my oil pressure sensor is not the switch type, my Silverleaf shows the actual oil pressure. At cold start up I see +60psi (or higher) and as the engine warms up the pressure starts going down and on hot idle it will be about 20 psi. A couple years ago another Monaco owner on IRV2 PM's me with a problem where the engine would start but he had a check engine light and the throttle was limited. He did not have any other type of VMS so no idea what the ECM was seeing for oil pressure. After ruling out a bunch of the other causes I suggested that it might be his oil pressure sending unit. He took it to Cummins and the replaced the sensor with a switch and then reprogrammed his ECM for the switch option. The original oil pressure sensor is obsolete so if you take it to a Cummins shop that's what they'll do, for ~$400. But I found some posts on IRV2 that had a Cummins part number for a sensor that would replace mine it does fail. So I bought one to carry as a spare. I have not swapped it out but the IRV2 poster swapped his and it worked. Link to comment Share on other sites More sharing options...
tmw188 Posted July 23, 2022 Share Posted July 23, 2022 Jim are you saying the trans temp sensor on your 8.3 is not available anymore if needing replacing? Do you have that P/N of the replacement you found? Todd Link to comment Share on other sites More sharing options...
jacwjames Posted July 23, 2022 Share Posted July 23, 2022 No, the original engine oil pressure switch, which provided actual pressure reading, is not available anymore. Cummins will only sell a switch type sensor and then reprogram the ECM, if you use any type of monitoring system it will show 55 psi all the time. Link to comment Share on other sites More sharing options...
tmw188 Posted July 24, 2022 Share Posted July 24, 2022 Ok so it’s the oil pressure switch that was mentioned above, do you have that PN for that switch I’m sure mine is the same. I use a ScanGauge to monitor that parameter. Link to comment Share on other sites More sharing options...
Chuck B 2004 Windsor Posted July 27, 2022 Share Posted July 27, 2022 On my 2004 Windsor there are 2 ECM programing parameter for oil pressure, True oil pressure or 60 pound pressure. I had mine changes from 60 pound to true pressure. Chuck B 2004 Windsor Link to comment Share on other sites More sharing options...
jacwjames Posted July 27, 2022 Share Posted July 27, 2022 From what I understand (read on the internet from multiple source) is that if my OEM oil pressure sensor fails and take it to Cummins for repair they will install a new sensor that is basically a 55 psi switch and then will reprogram the ECM to show this pressure. They do not give you an option. Several years ago I had helped another Monaco owner with a CEL and derate, he ultimately took it to a Cummins shop and they replaced the sensor and reprogrammed the ECM, he was happy he got it fixed and didn't use any other monitor so didn't care if the ECM was seeing a switched 55psi. His dash gauge worked. When I go to the Quickserve site it shows the OEM sensor was superseded and not available. That is why I did some research and found a possible alternative to my OEM sensor that "should" work. Link to comment Share on other sites More sharing options...
CTerry Posted July 28, 2022 Share Posted July 28, 2022 When I first bought our 2003 Beaver with the ISC 350 Cummins I questioned the dealer about the 55 psi reading on the Alladdin screen. They called the factory and got the same answer they were giving me for everything else that was wrong. That's the way it is supposed to be. Link to comment Share on other sites More sharing options...
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