2003 ISL400 Where is the oil press sender?

[wamcneil]

Hi all. I've got a warning light on the dash and bluefire says there's a error code (PID) Engine Oil Pressure low voltage or shorted. Dash gauge reads good oil pressure so I'm pretty sure it's a bad or disconnected sender.

Where is the ECM's oil pressure sensor on this motor?

[DavidL]

24 minutes ago, wamcneil said:

Hi all. I've got a warning light on the dash and bluefire says there's a error code (PID) Engine Oil Pressure low voltage or shorted. Dash gauge reads good oil pressure so I'm pretty sure it's a bad or disconnected sender.

Where is the ECM's oil pressure sensor on this motor?

Someone that has more product specific info should chime in, but the gauge that reads "good oil pressure", might be a "CAN" communication gauge meaning...it's getting it's oil pressure data from the engine ECU.  I highly doubt it's a mechanical pressure gauge, but it could be an electric analog gauge where it might get it's data (voltage) from a secondary oil pressure sensor.

So, to be safe, have an oil pressure test taken using a mechanical gauge.

At a minimum, check the oil level and top up and look at the viscosity of the oil on the stick.

Get a second scan tool to double check that there is a PID for that issue.

Based on the PID message, the sensor isn't disconnected, but the wire might be shorted together (hungry squirrel damage)

Edited April 15, 2023 by DavidL

[wamcneil]

Thanks. I drove it 80mi on the highway before checking the codes!  The oil pressure warning light and dash gauge are working, so apparently on a separate sensor. And I’m pretty confident the lubrication system is working properly. 
Anybody know where the sensor is located?

[jacwjames]

You might do a part lookup for the Cummins sender and then do a YouTube search on how to replace, somebody surely has posted one for that.

My engine is an ISC but for reference my sender is on the passenger side above the starter.  In my case Cummins has done a change on the part, if mine fails the new part is actually a switch and the ECM has to be reprogrammed to accept the new input AND I would only see 55psi on my Silverleaf display.   This has been a topic of discussion on IRV2 and one member posted that an oil sender from an ISB engine would work and that it would still provide proportional readings, he actually bought one and tested it.  So I went ahead and bought one to carry as a spare. 

[wamcneil]

In case anybody else is curious about the location of this oil pressure sensor... I finally found a good diagram in the troubleshooting and repair guide on quickserve.cummins.com. I haven't actually put my hand on this yet, but it looks to be accessible from the bottom. 

 

[wamcneil]

That sensor was the problem. Just like Jacwjames said, it's easily accessible from underneath and just above the starter. There's a second 2-wire sensor close to it that I assume is for the gauges.

Apparently on the ISL it's a switch, not a sensor; the original switch had the same P/N. I didn't need to program anything and the code went away immediately. 

Weird how things happen in threes. Until recently I don't think I've ever had a vehicle oil pressure sensor/switch go bad on me. Now it the last 12mo I've had to replace oil press sensors on two cars and now the bus.

Error code gone. Won't be able to get it out and drive it for a while, but I'm really hoping this makes my jake brake start working again...