Going down a rabbit hole and need your feedback...


Got a 2002 Automatic Protege 5 2.0L with a possible short circuit issue

Background info:

Bought the car for cheap knowing it doesn't start. No CEL or OBD Codes. So I troubleshot all the basics (get fuel, no air restriction and get spark) with some parts replaced such as CKP sensor and the Cam Sensor and new battery. After these replacement parts the car wanted to start better than before but couldn't. I then looked at list I found online for other parts and the EGR was one of them and this is where it gets interesting for me.



The Rabbit Hole:

While inspecting the EGR I noticed it was quite warm to the touch. The engine doesn't start so it can't be driven so why is the EGR hot? The ignition is in the off position so it must be getting power constantly to it. I have a Flir One Pro and I used it to take a photo of how hot it is getting with an astounding 140F. The first thing that came to mind was “there must be a short circuit”. But no fuses popped.







So my main question is before I get to too detailed into other troubleshooting steps I have done is, “Should the EGR always have power with ignition off and be this hot?” My thoughts are “No”.

Nothing on the internet indicates that should be normal but also nothing on the internet that says it’s not. I just find it off or hard to believe that would be normal. My understanding is that the EGR has a power wire (WHT/RED O) that sources from the Main Fuse box directly to the connector of the EGR valve but also the same hot wire feeds power to other components like (Purge Solenoid Valve, Mass Airflow Sensor, Canister Drain Cut Valve & EGR Boost Sensor Solenoid valve).

Main Fuse Box with (WHT/RED O) wire to EGR Circuit


Wht/Red power wire to EGR shown in wiring diagram.

With the ignition on, I checked the two wht/red power wires at the EGR connector on terminals C & D and I get battery voltage as expected.

When I check voltage at the fuse box with the Ignition off I still show some power (.09V) of the 20V max range on my MultiMeter

Low voltage with Ignition off. Power from Main Fuse Box

I disconnected the battery power cable and performed a continuity test with the EGR connector (wht/red) wire and the lead inside the fusebox that makes connection to another connector of the same wiring color scheme and it tones out with good continuity. The wire coming from the EGR connector enters the Main Fuse box from underneath.



When I perform a continuity test with the Connector in the Main Fuse box I get nothing. I was expecting a tone out but I guess that could be normal since I am not directly completing the circuit with the connector being in place?

Conntinuity Test with Fuse Box Connector, no tone.

I am guessing that possibly the Main Relay could be the culprit being faulty and providing power when it shouldn't or there is a ground fault. Not sure but Looking forward to your feedback!

 

**Update**

This will go down in my WTF memory of books. The culprit was my OBD2 Bluetooth DTC Code Scanner left connected to the OBD port. That completed a circuit that powers the EGR and several other components on the same circuit. In case anyone comes across this for future reference.

 

Thank you so much, you saved me a headache. I just had the same thing happen to me a moment ago, and you see, I've just finished making several repairs to my P5.
For some reason I started checking if I had oil leaks or something, and it just occurred to me to touch the EGR, god, I swear I made a thousand hells in my mind thinking the worst, because just like you say, there are no DTC codes, I simply disconnected the EGR and looked for information on the forum, and as a great relief you and your post arrived. Thank you very much friend and know that you really helped someone from another part of the world.
Greetings and blessings from Guatemala