I have a 2004 Trailblazer and I need to replace the motor. I bought a second hand motor for it but the new motor has a sensor at the bottom of the base pan that my old engine does not have. Does anybody know what this is for? Or more importantly does anybody know what I need to do in order to add/bypass this sensor to my vehicle? Unfortunately, I do not know what year vehicle the new engine came out of. Any help would be much appreciated. It's the 4.2L engine

 

How about a photo?

Is this the oil pan?

Aren't you using your current computer system? You would have nothing to plug it into, so no need to bypass, right?

Generally you take the parts off your engine and put it on the replacement engine that don't fit your application.


I had a 2.8L from a w-body that I had to transfer parts to from my 2.8L j-body motor to make it for my j-body.

 

Its a low oil level sensor. Just leave it unplugged.

 

I will send some pictures of it tomorrow. If I leave it unplugged won't I throw a check engine light on the dash? The new engine that I bought came complete with throttle body. ECU, harness etc.....the new harness was different as the transmission plug was different and it had this extra wire for the low oil level sensor. So I guess I should put the old harness on the new motor, change the ECU's and then leave this sensor unplugged.

 

Install the old harness on the new engine. Forget about the sensor on bottom of the pan or install your original. Why change the ECM? Same engine, right?

 

Hey guys got the motor in and running. What I did was use my old harness and old ECU and she is running like a dream. Thanks for the help.