Alright guys so I get in from vacation been gone about a week... Jump in the truck for a 30 mile drive all highway... Starts up great no issues whatsoever. Check all the gauges over and everything is good...

I get about 15miles into my trip and my CEL kicks on and I notice my oil pressure on the high end of the the 'normal' range.

Normally my oil pressure is two needles above the center mark when cold and then 1 needle below the center once everything is warmed up...

So I pulled off as soon as I could and popped the hood and checked the oil (thinking crankcase is full of fuel)... Oil level was within safe range and didn't smell of fuel at all.

Checked my codes and I got my normal speed sensor code (always there), as well as a new one to me P1475 5 volt auxiliary voltage supply high... Never heard of this one before... ?? What's up with my baby???

 

Probably ECM. ECM provides the 5V aux voltage that feeds the sensors.

Or so I think I thought I saw o heard. It could be a voltage regulator too if there's one of those in the mix. You have a FSM?

jh

 

Not sure about the oil pressure. Did you change brands/type of oil.

Mine threw a charge system code, don't remember the number, the first time the grid heaters went on hard and strong this year. I think it came back one time since then. Now, when heat heaters are on hard, the "Check Gages" light stay on for a few seconds when first started. The alternator is charging a volt or two higher like it usually does when it's cold.

 

Test voltage at the reference wire going into the oil pressure sensor, should be .5v reference. It is supplied by the ecm as stated, but if the sensor went bad....could possibly be backfeeding the wrong voltage to the computer.

 

Mine oil pressure gauge used to work as you describe, then one day I noticed it was on the high side as well, even when the key is on and engine is off, after pricing a sensor (80+ dollars) I decided I dont need the gauge, not like I look at it anyway, I think an idiot light would be better.
BTW mine does not trip the CEL light

 

Brian, you don't have a mechanical oil pressure gauge?

 

Thanks for the responses will try this ASAP...

 

Nope only 6 gauges in the truck... No oil pressure!!

 

No offense, but thats not too good when ya have a $3000 engine sitting under the hood.

 

I feel naked w/o oil pressure, boost, EGT and fuel pressure (2 in the case of CTDs).

 

... 'fraid it's a bit more $$$ than that!

 

What, no one trust the factory "guage"?

 

Heck there's more than that in the head!!

 

What gauge??

Wont be able to tend to the truck until this weekend.. Will post back with my findings... Hopefully it's just a sender..

XLR8R... so what does the gauge genius recommend for an oil pressure gauge location??

 

Wait a second... Are the factory oil pressure gauges not worth anything? I haven't read anything on this site that suggested poor readings. Maybe i'm not catching your sarcasm on this issue.