Engine/Transmission (1998.5 - 2002) '01 oil press sending unit FAILED AGAIN.....

[Jim Ross]

The oil pressure sending unit in my '01 has failed again, this is the 2nd time since new. The first time it failed, I went to Cummins and bought a replacement for less than $80 and installed it... . no muss, no fuss everything was fine. This time it is a different story! Cummins no longer supplies the oem unit and says it is only available from Dodge. OK, here is the rub: Dodge only offers a replacement unit with a 1-pin electrical connector (the oem unit was a 3-pin). The oem unit actually measured the pressure, the new 1-pin unit is just an idiot light type unit, it only registers pressure or no pressure. It effectively turns the dash gage into a meaninless gage. Now here is the REAL steamer... . the new 1-pin unit requires a computer reflash in order to work and Dodge wants $150 to reflash my computer... . this because THEY redesigned the part and the oem part is no longer available!!! I can understand that I should have to pay for the new unit because the truck is out of warranty, but I do NOT think I should have to pay for a computer reflash because THEY changed the design of the unit.

I have had all my local parts store guys looking for an original 3-pin unit for me and no one can find one anywhere. Currently, I am driving with the faulty oem unit unplugged, so I don't get the constant warning chime and dash warning light..... and the oil pressure gage reads 40psi all the time... . I know it is not correct and I know I have oil pressure, but I would like to find a source for the oem 3-pin unit and install a new one.

Any ideas from the group?

 

[rweis]

I added an OP gauge and sender to cross check the OEM. I put mine in the cubbyhole. Not a fix to the OEM one, but at least you control the device and it reads correctly under all conditions.



Maybe a salvage yard might have the OEM sender?



Bob Weis

 

[Jim Ross]

Thanks, Bob. I am really hoping someone out there has a source for the oem unit. I use my cubby hole for my sun glasses, so don't really want to put a gage in there, plus then I still have a useless gage in the dash.

 

[rweis]

Yeah on the gauge in the dash and I was thinking (dangerous for sure). I replaced the DC fuel level sender with a marine mechanical unit and then figuered the parallel resistor to make the DC gauge read correctly (testing that part right now and it looks pretty good).



The fuel level sender gets 12 volts and then has a variable resistor that changes that voltage (by use of a resistor (float level unit) to xx voltage. Then the canbus takes that voltage and reads it every xx seconds (seems to be about every 60 seconds or so) and sends a signal to the fuel gauge as to where to move the needle.



I wonder if the oil pressure sending unit with the 3 leads is doing the same thing?



1 lead for ground as a reference, 1 lead for the 12 volt feed, 1 lead for the return voltage to the canbus so the canbus can send its signal to the op gauge as to where the needle should be.



The new DC is a ground or no ground ie op or no op ie idiot light.



If we can figuer out the wire coding that are the 3 leads, find ground, find 12v, and someone with an operating op gauge take some readings at various pressure levels (20,40,60,80) we can see what the range of the voltage should be and do the same as we did for the fuel level gauge.



The DC fuel ohms was 20 - 220, the industry standard is 35 - 240. A 2400 (I think, might be 2700) ohm resistor parrallel across the industry standard 35 - 240 corrected the difference in ohms so the DC gauge reads correctly (I am checking the linearity right now).



What are the ohms of a say Stewart Warner op gauge / sender?



Mount a SW op sender where ever you want. We figuer the differences between the DC and SW ohms and figuer the size of the parallel resistor. Put the parallel resistor on the SW sensor and fed the result to the DC canbus. That is what I did for the fuel level sender and it seems to be just fine (and the SW sender is easily obtainable at NAPA, you choose the mounting location to make it easy, solder the parallel resistor to the DC wiring so you only do that once ever, and you have your dash op gauge back and you KNOW it is giving good info).



Works for the dash fuel gauge, why not for the dash op gauge?



Bob Weis

 

[Jim Ross]

Wow... ... . you know LOTS more about electronics than me! My brother is an electrical engr/circuit designer and he speaks your language, but me?... I'm just a shade tree mech... . decent with nuts/bolts, but electronic wizardy is stuff I leave to experts/knowledgeable folks like you! I do follow your logic though and it makes sense.

 

[rweis]

Well,



The resistor value idea came from Gary (REALLY GOOD with electronic ideas, GOOD problem solver, and tester),



The mechanical sender idea came from a duck hunting buddy (let me show you the mechanical sender I have in my boat),



The company (Tempo) came from internet ressearch,



Mounting the flipping thing backwards came from me ,



Mounting the flipping thing correctly came from trial and error,



The seepage leaks are from the mounting it backwards holes, but I have found a diesel proof sealer I think will fix the "extra holes" and the seepage (and warned others not to do same ),



The motivation came from TDR guys, and trying to beat DC at their own proprierity gauge game (that will be $300, step over to the cashier window please),



The testing I like to do anyway to prove there are other ways around "unsolvable" annoyances (I love problem solving).



The PATIENANCE comes from my WONDERFUL wife that does not wonder "why is the fuel tank out AGAIN (about the 6th time, maybe I should mount it with velcro?)"



Bob Weis

 

[Nuka]

Jim

I'm having the same problem, however i got a new sender from my local Cummins dealer and it is P/N 4921511. There have been several numbers that superceed each other but supposedly this is the one we need. Good luck

Joe 01 dodge

 

[Jim Ross]

Joe,
Have you actually installed the new unit (P/N 4921511) and it has a 3-pin connector, and found that it works correctly? I sure hope you answer "yes" because if that is the case, I will go to the local Cummins store and try to buy it!!!!!!!
When I replaced my first one, the P/N was 3408428 (cost was $68. 75) and as I mentioned in my first post, that P/N is no longer available. When I tried to get another one about 2 months ago, the Cummins parts guy took my engine serial number and gave me the bad news. ... . maybe things have changed?
Thanks,
Jim

 

[Nuka]

Jim

I just got it changed about an hour ago. Went for a short test drive and it appears to have done the trick. My original was pretty big as far as the diameter of the wrench flats. It took a 1 1/4" deep socket to get the original one out, but the replacement was a 1 1/16 which i bought a special socket for. Oh yea and it is one with a 3 pin type also. 79. 99 at cummins plus 15 bucks to ship it up to me. hope this helps let me know if you need anything else. Joe

 

[azpete]

My sender unit went out last year. Checked with the dealer and they wanted $230 for one #@$%!. Figured my next option was a after market guage off the filter housing but I'm running out of places to put gauges. Our local Cummins shop left town afew years ago so I may have to check around Phoenix for prices.

 

[OakViewJeff]

My local Cummins dealer in Ventura, CA found the original sensor made by Mopar through a reseller in Indiana. The Mopar P/N is 1-05012991AA for $44. This is a 3-pin switch, however the 3-pin connector on my '99 is smaller than the connector on the replacement switch. Whe you look at the Cummins Parts Catalog on-line, they show 2 different sensors for the '99 engine.

Anyone else have the connector interface problem?

 

[Thomas]

To add to the confusion, from D/C STAR FAQ:

Technicians are removing oil sensors and turbo boost sensors, often not knowing which is which. How do we properly identify the sensors on the BR/BE 24 Valve, Code ETC, Turbo Diesel? - Top
The 5012991AA Oil Pressure sensor is stamped 3348749.
The 5012991AB Oil Pressure sensor is stamped 3408428
The 5012801AA Turbo Boost sensor is stamped 3348747
The 5017791AA Turbo Boost sensor is stamped 3417030
Note: the sensors look the same, but the mating connectors are different.

The STAR information matches Mopar part numbers with Cummins part numbers. P/N 50122991 is shown in the 2000 Parts Catalog.

And a few old TDR threads:

https://www.turbodieselregister.com/forums/24-valve-engine-transmission-1998-5-2002/53678-24v-oil-pressure-sending-unit.html
https://www.turbodieselregister.com/forums/24-valve-engine-transmission-1998-5-2002/128038-oil-pressure-sensor-replacement.html
https://www.turbodieselregister.com/forums/products-accessories-engine-transmission/129348-need-oil-sending-unit.html

I imagine with all the parts numbers in this post plus the links you'll come up with something

My 2000 Parts Catalog shows 5012991AA.
My 2002 Parts Catalog shows 5083366AA.

One of the above links states that the 5083366AA sender (the switch) appeared model year 2001. 5.

 

[Jim Ross]

Joe,
Thanks a million for the part number! I ordered one from the local Cummins dealer and it works fine. Cost was approx. $84. The old unit has a 1-1/4 drive and the new one is 1-1/16, just as you said. The electrical connector was a perfect match.
Jim

 

[Wyomingcowboy]

Maybe you guys can help me out..... My pressure unit has been bad since I bought the truck a year ago. The reading is a steady 70-80 on the dash from the time the key is on even without engine running (at the high end of the gauge but not up to the 110 or whatever) SO, I bought a used replacement from e-bay and finally plugged it in today and now a similar problem, except it goes to about 40 and stops with the key on and engine not running. No difference when engine IS running. When yours went bad were the symptoms the same? Is the part bad? Can I test it? What else could be causing this?



I am dreading a trip to the shop and don't like paying $$ for parts unless I know for sure that it's needed.

Thanks!

 

[Wyomingcowboy]

OK... . perhaps the only thing that kicks my butt more than math is patience. I couldn't wait for you guys to reply so made a few calls and found a Cummins dealer here in town that had two of the 4921511's. After our state sales tax of 4% and the optional local sales tax of 1%, I paid a total of $79. 67. (It would have been $68 from another place that would have had to order it, plus the shipping they were gonna stick me with. ) ANYWAYS, I took the chance and installed it and surprise! oil pressure!! Thanks for the part #. It fits exactly how you said and the electrical connection too. This is exactly the reason why I joined this site!

Muchos Gracias!

 

[Wyomingcowboy]

OK... . perhaps the only thing that kicks my butt more than math is patience. I couldn't wait for you guys to reply so made a few calls and found a Cummins dealer here in town that had two of the 4921511's. After our state sales tax of 4% and the optional local sales tax of 1%, I paid a total of $79. 67. (It would have been $68 from another place that would have had to order it, plus the shipping they were gonna stick me with. ) ANYWAYS, I took the chance and installed it and surprise! oil pressure!! Thanks for the part #. It fits exactly how you said and the electrical connection too. This is exactly the reason why I joined this site!

Muchos Gracias!



Now perhaps you could enlighten me as to normal operating pressures as I have no experience with it:-laf



At idle with a warm temp I run a little less than 40. At highr rpm's cruisin around town I am up to about 70? (The goofy gauge pegs at 110 but midway is 40, so I am guessing on the 70. )

Does this sound right?



Thanks again!!

 

[fest3er]

As uncalibrated as these gauges are, 40-70 PSI, indicated, is in the ballpark. That's around where mine has run for 10 years now. Except when the sender goes bad; then it drops 5 PSI or so.

I guess some Cummins shops are more ... pleasant than others. I think I paid about $48 for mine, which included $15 overnight shipping from the factory. For my CPL, the sensor part # is 3932300. Bring your engine serial # to your local Cummins shop and they'll look up the right part #. IIRC, 3932300 is pert near the *only* sender they use in the Dodge application.

See my post in this other thread.

 

[Wyomingcowboy]

WOW! $48? I am always looking for deals but then the whole patience thing comes into play... sounds like I got off far better than alot of guys though... . $250+/-