Just noticed today that the oil pressure is way high while driving and not really moving even upon reaching operating temperature. Driving pressure at low throttle is 60-70 at full temp. and idling is right around 60. Here's the gauge, full operating temp. while idling...

Even before starting, the gauge shows 40, then after start up right to the 60-70 mark and doesn't move much. I'm hoping this is just the sending unit and not a bearing or electrical problem. Any insights? Thank you

ps...I know I have oil pressure because I didn't tighten the turbo oil return line enough and it was leaking, I tightened a couple days ago and no more leaks.

So same as above, on the way to work....ding-check gauge msg - no oil pressure. Checked it with a mechanical and suspect bad sensor. Been reading and appears old style used a transducer, then they went to a switch which was only on or off but gave a gauge reading to make you feel warm and fuzzy....I think it depends which switch you have installed. Just like dodge did with the alternator (why they had to be a unique snow flake ??) the switch/transducer goes through ECU......ecu feeds gauge

 

My question-----does the ISX use a switch or a transducer......see them on ebay for like $30....3 pin plug....will it work on a 24v?

 

 

Matt

Here's the video that helped me from Thoroughbred Desiel

I still have codes p0522 and p0523 for oil pressure high voltage and low voltage. Any ideas?

This might be a silly question, did you clear the codes after you installed the new sender? Dont mean to offend or anything.

Codes wouldnt pop up on my little $100 matco scanner. They're stored on the ECU using the key trick. Ive put over a couple hundred miles since the install and they're still there, gauge is back to normal so unless you can clear codes with a key trick im stumped

No way to clear them without a good code reader. Try stopping by the local Orielly's or Autozone. Their readers are actually not bad and you can clear codes with them. Thats what I always do at least..

Mike, I saw your video where you disconnect the coolant temperature and the oil pressure dips and I believe I see what is happening. As you no doubt know the PCM is  the  communications master for the ECM, timer module, ABS, and Instrument cluster via serial communications and is very taxed for processing power being it was a 1998 design.  In 1998.5 Dodge had numerous re-flashes because lack of timely communication servicing between computers causing the instrument cluster (mostly serial communication rather than individual wiring) to go to zero indication and sound alarm. All works good now for no faults on the I/O but even a single bad input can send the software into a fault handling subroutine that slows the scanning cycle and cause the symptoms you see on the oil gauge. They even have a dealer notification  telling the owners the +-50 RPM fluctuation on the tach is due to this problem of "not updating in a timely fashion". I think the oil gauge is fairly accurate as long as there is no outstanding  I/O faults. I think Dodge even used a simple on/off switch (rather than analog voltage)  to make the oil gauge read 60% in a future model year so owners would not complain so much but owners were just not that dumb. 

When I first got my 2000 CTD the auto transmission drove me crazy in the city locking and unlocking the torque converter so I put in a dash switch to interrupt the TC lockup solenoid coil and drive unlocked in the city all the time. To my surprise I set a code in  the transmission causing "limp mode"  where it went second  gear with full hydraulic pressure (harsh). I was surprised that it sensed the open circuit and went limp mode  since  my 1997 had this work okay with the simple switch.  With the 2000 I had use a relay to switch in a resistor that looked like the coil impedance and sort of fool the computer digital output current checking.  The bottom line is there are many many ways to set a code in this setup that can be difficult to track never mind spawning spurious computer glitches that appear to affect the instrument cluster. Must drive dealer mechanics nuts.

Edited April 16, 201411 yr by balsip