Dodge Repair Questions? Ask a Mechanic for Answers ASAP
Hi, I am Mike, welcome. I'm reviewing your question.
There are three exhaust gas temperature sensors in the system. The first is located upstream of the Catalytic Converter. The second is located in the Catalytic Converter. The third is located upstream of the Diesel Particulate Filter.
Here is a test procedure for testing that sensor 1/1 which would be upstream of the Catalytic Converter.
that test says to let it sit for 60mins. which it has. it says that pre cat and post cat should be within 50*F of eachother. my scanner shows "pre catalyst temperature" and "exhaust gas temp pre cat" then the same for post cat. the "pre catalyst temp" is steady at 122*F; but the "exhaust gas temp pre cat" is at 80.6*F. these two don't change at all (key on engine off). now, the post cat readings fluctuate from about 80*F to 84*F. they just bouce back and force a little. since the pre cat temps don't change at all, im assuming this is a bad pre cat egt sensor?
Check the ohm readings of that Upstream Catalytic Converter Temperature Sensor.
I got .218
.218 what? Ohms? At what temperature? Whichever though it sounds way too low. It starts out at 265 ohms at 212f.
my multi meter on ohms showed .218. I just checked again and it showed .217, so I plugged the sensor back in and checked the scanner and now all of the pre and post cat temps are showing 73.7*F. if I unplug it the value goes to almost 600. plug it back in and goes back to 73.7*F. maybe there was a bad connection in the plug? ( this is the same value that was at 122 while the rest were at 80.) now it shows the saem as the others
Unplug what? What value goes to almost 600? 600 what? 600 degrees f? 122 what? 80 what? If you don't include that, I will just have to ask.
it sounds as though you figure it out, a loose connection.
well we are talking about the pre cat egt sensor remember? this testing is for that sensor. let me be I little more specific. I first checked the pre cat and post cat temps with my scanner. pre cat was 122 degrees Fahrenheit. post cat was 80-84 degrees. this is within the 50 degrees the procedure recommends. then you asked me to check the ohms of the pre cat egt sensor. so I unplugged the sensor and put my meter on the ohms setting. I put one lead from my meter on one wire of the plug for the egt sensor and the other lead on the other terminal. since this is only a 2-wire plug.. my meter then showed " .218" OHMS. now the procedure chart you provided starts off at 212 degrees F at 265-285 OHMS. but my truck is not that hot; its only about 80 degrees. so with a lower temp the ohms reading will be lower. when you questioned the .218 I went and double checked because you are the expert here, not me. the second time I checked the egt sensor for ohms it read ".217" ohms. so I grabbed my scanner to check the temperature of the exhaust because you asked. I plugged the egt sensor back in and it read 73.7 degrees F, along with the other sensors. so i unplugged the sensor again while watching the temp value on the scanner. when i unplugged it, it went up to about 600 degrees. when i plugged it back in it went back to 73.7 degrees.
well then just ignore that 600 degrees then since when you unplugged the sensor, then reading most likely just maxed out.
replace that Upstream Catalytic Converter Temperature Sensor and see if the code goes out.
are they expensive? did you price it yet?
Here is a video "Sprinter van Exhaust System Sensor cleaning P0544 code", https://www.youtube.com/watch?v=qgqqLOD6w1I
Here is one for $133, http://www.mopardealerparts.com/p/Dodge__SPRINTER-3500/SENSOR-Temperature--Temperature-Sensor-Upstream--Of-Diesel-Particulate-Filter--Temperature-Sensor-Upstream-Of-Diesel-Particulate-Filter/42427272/68012052AB.html
I would try the cleaning, maybe it will work but first I would get the exhaust up to at least 212f and check that ohm reading again.