ok guys, quick question, does your oil pressure gauge show a pressure reading after you shut the engine off??



trying to figure out if its always read like this and i missed it or if my pressure sensor is on its way out.

 

Mine always goes to zero, but I have the old style gauge cluster. When you shut the key off then just cycle it back to run does it zero out?

 

no thats what is bugging me, i thought it zeroed out as soon as the engine shut off, but in the last week or so i noticed that it isnt doing that, i can turn the key on in the morning and it is sitting at the same spot as in that picture, my first thought is that my pressure sending unit is shot so as soon as i get a reply from someone with a 01/02 truck i think im going to order one and put it in.

 

hey Shrp mines sits past the L i would say something is wrong with yours an with the key at the start position its on the the L

 

Reset the cluster.

 

i ran a cluster self test already and it came back clean, it does go all the way over when the key is off, but comes back up as soon as the key is on

 

Is there something stuck on the sensor, I know even with changing your oil every 3k short trips can cause sludge to form. But mostly likely it is a bad sensor.

 

I havnt pulled the sensor out, we do 5k mile changes and have exactly 0 evidence of any build up in the engine, im going to try a complete reset of the modules and cleaning sensor contacts tomorrow then go ahead and replace the sensor

 

Well the sensor is just a resistor, you could try to unplug it and see if it drops, if it does then there is your problem. You should also measure the power coming into the connection to see if you have a slight drain or a simple bad gauge.

+1 on cleaning the contacts.

 

This should keep you busy for a little while.
OPERATION
The oil pressure gauge gives an indication to the vehicle operator of the engine oil pressure. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus. The oil pressure gauge is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the On or Start positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the Off position. The instrument cluster circuitry controls the gauge needle position and provides the following features:

Engine Oil Pressure Message - The instrument cluster circuitry restricts the oil pressure gauge needle operation in order to provide readings that are consistent with customer expectations. Each time the cluster receives a message from the PCM indicating the engine oil pressure is between about 6.9 kPa (1 psi) and 137.9 kPa (20 psi), the cluster holds the gauge needle at a point about 11 degrees above the low end of normal increment on the gauge scale. Each time the cluster receives a message from the PCM indicating the engine oil pressure is between about 517.1 kPa (75 psi) and 755 kPa (109.5 psi), the cluster holds the gauge needle at a point about 7.4 degrees below the high end of normal increment on the gauge scale. When the cluster receives messages from the PCM indicating the engine oil pressure is between about 137.9 kPa (20 psi) and 517.1 kPa (75 psi), the gauge needle is moved to the actual pressure position on the gauge scale.
Engine Oil Pressure Low Message - Each time the cluster receives a message from the PCM indicating the engine oil pressure is below about 6.9 kPa (1 psi), the gauge needle is moved to the L (Low) graduation at the far left end of the gauge scale, the check gauges indicator is illuminated, and a single chime tone is generated. The gauge needle remains at the low end of the scale and the check gauges indicator remains illuminated until the cluster receives a message from the PCM indicating that the engine oil pressure is above about 6.9 kPa (1 psi), or until the ignition switch is turned to the Off position, whichever occurs first. The cluster will only turn the check gauges indicator on in response to an engine oil pressure low message if the engine speed message is greater than zero.
Engine Oil Pressure High Message - Each time the cluster receives a message from the PCM indicating the engine oil pressure is above about 755 kPa (109.5 psi), the gauge needle is moved to the H (High) graduation at the far right end of the gauge scale. The gauge needle remains at the high end of the scale until the cluster receives a message from the PCM indicating that the engine oil pressure is below about 755 kPa (109.5 psi), or until the ignition switch is turned to the Off position, whichever occurs first.
Communication Error - If the cluster fails to receive an engine oil pressure message, it will hold the gauge needle at the last indication about forty seconds or until the ignition switch is turned to the Off position, whichever occurs first. After forty seconds, the cluster will move the gauge needle to the low end of the gauge scale.
Actuator Test - Each time the cluster is put through the actuator test, the gauge needle will be swept to several calibration points on the gauge scale in a prescribed sequence in order to confirm the functionality of the gauge and the cluster control circuitry.
The PCM continually monitors the engine oil pressure sensor to determine the engine oil pressure. The PCM then sends the proper engine oil pressure messages to the instrument cluster. For further diagnosis of the oil pressure gauge or the instrument cluster circuitry that controls the gauge. If the instrument cluster turns on the check gauges indicator due to a low oil pressure gauge reading, it may indicate that the engine or the engine oiling system requires service. For proper diagnosis of the engine oil pressure sensor, the PCM, the PCI data bus, or the electronic message inputs to the instrument cluster that control the oil pressure gauge, a DRBIIIŽ scan tool is required. Refer to the appropriate diagnostic information.