Check Oil Level Light

[AB Dave]

The 'Check Engine Oil Level' light will not shut off on my 1999 Chev 2500 with a 6.0L engine. I replaced the sensor, but it didn't help.

I found a comment on the net somewhere that said the sensor/switch is actually a closed circuit until the oil level drops to a certain point, then the switch opens the circuit and a high voltage spike is sensed by the PCM which commands the light to come on. So, with that information, I unplugged the sensor and ran a jumper between the terminals on the wire to simulate a closed circuit but the light stayed on. This indicates a short somewhere in the circuit between the sensor and the PCM so I traced the wires back to the PCM and didn't find any problem.

As such my question is; Is the sensor/switch indeed a closed circuit when the oil level is OK or is it an open circuit that closes when the level gets too low?

 

[Parts007]

I didn't answer your question, but did you do this:

Condition/Concern:

The "CHECK OIL LEVEL" message may display after a repair, if the key is left on when doing an oil change, or after topping off the engine oil due to a low oil condition. When using the Tech 2® to view the engine data parameter "Engine Oil Level Switch" it will show "OK", but the "Check Oil Level" message will still be displayed on the DIC. This could be caused because the engine coolant temperature criteria, to reset the "Check Oil Level", has not been met. The system must see a 50°F (10°C) drop in engine coolant temperature to recheck the engine oil level and if the level is okay then the DIC message will turn off.

Recommendation/Instructions:

To correct this concern, allow the engine to run until operating temperature is reached and then shut the engine off and allow the engine to cool down for about 1 to 2 hours with the key in the off position. Upon the next key cycle, if the engine oil level is okay, the DIC message will be off.

 

[Parts007]

The Oil Level switch is a normally open switch. When the oil level is within an acceptable range the Oil Level switch closes. The switch opens when the engine oil level drops below a predetermined amount. The PCM tests the Engine Oil Level switch circuit with the ignition ON (engine OFF).

 

[AB Dave]

Parts007, Thanks for the comeback. I completed the new engine install two weeks ago, and the engine has been at operating temperature and cooled down overnight several times, which should have satisfied the 50 degree temperature drop. I changed oil yesterday after having put the first 500 miles on it and did so with the key off of course. The engine didn't use any oil in that 500 miles so I didn't need to add any.

The information I read regarding the Oil Level Sensor being a closed circuit did not specifically mention that it is only a closed circuit when the proper level is met. I did assume that would be the case, and of course when the level dropped too low, the circuit would open. I noticed however that in my initial post I erred in referring to the possibility of a short in the applicable circuit keeping the light on. It would of course need to be an open circuit. So with that in mind, I traced the power wire back to the PCM and couldn't find a problem, I also checked the ground and it too is OK. Maybe it's the new switch. I'm going to install the original switch tomorrow to see if the new one is faulty. Wouldn't be the first time for that to be the case.

 

[AB Dave]

Re-installed the original oil level switch/sensor today. Didn't help. The light is still on. Called the service dept at the local GM dealer who suggested I bring it in because there could be several things wrong. I said give me a few, maybe I can fix it. Nope, they can't do that he said. I asked what their service charge is and he tried to make it sound like $127.00 per hour was a heck of a deal. I'm sure I can find a solution somewhere. If not a piece of tape is next.

 

[Parts007]

I would try checking for excessive resistance in the circuit, bad connector, bad wire. Copy attached.

 

[AB Dave]

Parts007
Do you know what the voltage should be at the connector that plugs into the sensor/switch?

 

[G-993958]

i have a problem with engine oil level when i checked oil it going down when driving about 6000k the oil level drops to minim i have acedia 2014 and also i repaired it in GMC workshop but still problem not finished

 

[van1964]

i have a 1999 gmc sierra the newer style i change the oil and now the oil level stays on and it didnt before