Bought a 2000 Montero Endeavor a little while ago. The drivers door sensor and light didn't seem to work but recently it started working again, sometimes. The map lights sometimes go off for a second then come on. Also having p0403 egr circuit check engine light code. Not sure if they are related, but I was thinking maybe they share a common ground that is losing continuity? I was planning on hunting around for grounds and shining them up with sand paper and spraying them with Deoxit contact cleaner. Anyone know where the ground locations? I saw a few on the intake and one by the battery.

 

The p0403 is almost always a faulty egr solenoid,but won’t hurt checking the egr system too..i dont think they have common grounds with the interior lights. Check fuses,maybe loose connections caused by dirt...this happens on bulb attachments.

 

Thank you for your help. I found you are right, the door sensors were their own issue (corrosion inside the sensor and sensor not grounding properly).

Is it possible for the solenoid to sort of work or work poorly but not throw a code? Sometimes it idles ok, sometimes it idles rough. I cleared the code a day ago and it hasn't come back on since but still idling rough. I took the EGR valve out, the portion the exhaust runs through, and cleaned it (though it wasn't very dirty). Must be the electronic portion is the one throwing the code?

I found a blown fuse, it was the vehicle alarm system. Also the alarm system siren horn was disconnected. When I connected them both, the system acts strange. It seemed to work ok at first, detected small bumps when armed. But after a few minutes, not sure what happened but it doesn't seem to go off anymore when the vehicle is jarred. Also the siren goes off when I pull on the wiper spray lever, which is odd.

 

Yes...the egr solenoid sometimes work or sometimes it just stops...and there are system checks made by the ecu before it throws a code..driving it for a few miles with certain engine load and speed and then see if the code appears again..its in this board somewhere...the steps the engine needs to go through before determining if there is a problem with the egr system.

 

Do you have the oe alarm system? Maybe there is a problem somewhere that’s why the previous owner disconnected it. If its an aftermarket alarm..they do tend to problematic after a few years.

 

Try cleaning the intake manifold..check the vacuum ports too...rough idle may be caused by a lot of things..

 

I ordered a new air switching valve, it was only ~$11 off ebay so maybe that'll fix it. I did check all around for cracks in the hoses but didn't see any. Maybe I should try the carb cleaner trick for checking for vacuum leaks, spray around the hoses and see if the idle changes? I'll try cleaning the intake if that doesn't help. Hopefully it can be avoided as there's quite a few things to disconnect to get the intake off.

Not sure if its the OE system. I don't have a FOB for it. I think the car was repossessed at one point so not sure if its the original ignition switch and keys. The lights on the dash flash on and off when the siren goes off. The siren is located next to the radiator and the fuse that controls it is a yellow one in the fuse box right next to the siren. Does that sound like the OE system?

 

i just sprayed throttle body cleaner on my intake and vacuum ports...took a pic first then removed the hoses so I wont mess it up when I put it all back...just make sure you put a rug underneath the throttle body as the fluid will leak out. A dirty throtlle body is one reason for a bad idle...