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spankyjr1, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 2602
Experience:  I worked on all types of equipment semis,forklifts,farm,ect.
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I have a 1991 peterbilt 379 with a cummings n14 celect , the

Customer Question

I have a 1991 peterbilt 379 with a cummings n14 celect , the engine is going to a safe idle mode when the oil preasure gauge drops to zero. the dealer ship advised me to replace the ecm which I did but the problem is still the same. now they have advise
me to change the oil pressure sensor but I cant find it. the manual I have tells me the location and how it looks but the people at Peterbilt send me a hole different thing and don't know where the location is. can you guid me to the location of my oil pressure
sensor ?
Submitted: 2 years ago.
Category: Medium and Heavy Trucks
Expert:  spankyjr1 replied 2 years ago.
Hi Customer, my name is ***** ***** you for your question.
If you are loosing oil pressure down to zero on gage red check engine light should come on and shut down engine after 15 seconds, not just keep it at idle.
Do me a favor and pull codes using cruise switches or diagnostic switch, here how below.
Here is a video of all sensor locations on this engine please copy and open in new tab to view
Turn the ignition key switch to the On position/ Engine OFF.
Turn the cruise control ON/OFF switch to the OFF position.
Move the SET/RESUME switch to either position. Hold that position until the yellow lamp begins to flash.
The yellow lamp will flash in order to indicate a three digit flash code and the SET/RESUME switch may be released. The sequence of flashes represents the system diagnostic message. Count the first sequence of flashes in order to determine the first digit of the flash code. After a two second pause, the second sequence of flashes will identify the second digit of the flash code,then third.
Any additional flash codes will follow after a pause. These codes will be displayed in the same manner.
Let me know codes
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