Any thoughts???????

Here's the scene.

2007 Chrysler T&C. SES light came on. Had a code P0073 for a bad ambient air temperature sensor. I didn't have time to mess with it, so my wife had our local Chrysler dealer check it. They replaced the sensor and erased the code. A couple of days later, the light came back on and the same code was set. My wife went back to the Chrysler dealer and the Service Manager said it was probably a problem in a wiring harness and could cost several hundred dollars to track down.

Since I really don't trust that dealer, and since it's a $20 part and takes 5 minutes to change, I replaced it with another new sensor from O'Reilly's. Same Result. Erase the code and about a day or two later it will set again.

Now, I don't know about the rest of ya'll, and maybe I've been lucky, but in all of the years I've been in the automotive business and in automotive service management, only twice on respectable, serviceable vehicles have I run into a problem that was a wiring harness, and both of those were loose grounds. Frankly, I'm not ready to accept that it's a problem buried deep within a wiring harness.

Do any of ya'll have any ideas?

My wife was driving this vehicle, and we were talking about replacing it anyway, so this issue provided the impetus for me to buy a Lincoln MKX for her to drive. I'll either wind up driving this Chrysler myself or selling it, and in either situation this has to be fixed.

Thanks for any ideas any of ya'll might have.

Heard today there is a recall on some Lincolns, at least in Canada.

The MKX is included if I remember correctly.
Steering wheel can fall off. 2 vehicles out of however many they sold the past few years.

Mice chewed the same harness in my wife's car twice. $200 each time to fix by dealer. They wrapped steel wool around it last time. So harness is a possibility.

I would replace the connector to that sensor before doing anything more.

I already checked. Ours isn't included.

Yes, it can easily be the harness. I know I'm going to get flamed for this but Chrysler especially, the 8-10 year old ones and older were notorious for issues like that. Sure the other companies too but to a lessor extent.

When I was working as a mechanic in an independent shop, out of ever 10 vehicles you saw on the roads in the local area 3 were GM, 3 Ford, 2 Chrysler/Dodge and 2 "others". Chrysler/Dodge made up 50% of our work.

Rick

I had a pick up once that the wiring harness rubbed through over the steering column.

My son had a '97 Mountaineer that was intermittently stopping with a crank sensor fault. He replaced the sensor; not good. He tracked the wiring harness and found that had been installed pretty tightly where it went through the upper manifold. (Theory was that after 20 years, the wire fractured) He just ran separate new wires and the problem appears to be gone.

In my lifetime the only harness problem I have been involved with was in a 2005 Chevy Duramax. Or at least that is what the dealer claimed it was. We towed it to the dealer and it came back fixed with the dealer claiming it was sa part of the engine harness.

Maybe small vehicles have flimsy wiring, I don’t know, but of all of the computerized combines I wrenched on I found zero harness problems. There was plenty of component trouble and grounding problems but nothing went bad in the harness.

Semi trucks have a maze of wiring behind the dash and going to the hood. The harness problems I have run into with them is age related outside of the cab, corroded terminals on 15 year old, million mile trucks. The only in cab harness problems have been caused by some bubba getting in there with his wire cutters to slice in for unneeded fancy lights or radios.

Now like I mentioned, maybe vehicles have flimsier wiring. When a car manufacturer gets in money trouble the first thing they do is lean in the outside contractors to cut costs. The contractors respond by sending the manufacturers cheaper components. And on and on it goes.

Some of the dealer techs just don't know how to do diagnostic testing. There is a growing number of diagnostic technicians that travel to dealerships when the dealer can find the problem. These diagnosticians don't fix the problem, they are not technicians or mechanics.
One example is New Level Auto on youtube.

I had a check engine light on my Mercury Sable years ago. The code said a bad egr sensor. Took it to the dealer, they confirmed it was a bad sensor and replaced it. The check engine light came on again on the way home. Took it back to the dealer. They checked further and found it was a bad wire to the EGR sensor. They had to replace the harness. They charged me nothing as they had mis-diagnosed the original light.

Sounds like you need to climb all over this dealer and then find a new one.

I?d agree it could easily be the harness.

I have a 2003 f250 and it started acting up. Found it was probably the throttle position sensor so I replaced it - and it cured the first set of symptoms but caused another!

Long story short - I gave up and took it to a real mechanic and he probed around for 15 minutes and then whipped out a knife and cut off a harness plug near where I?d replaced the first thing.

He?d found that the ground wire on that plug had broken inside the insulation! Apparently I had broken it while jostling around replacing the tps.

It was a very interesting lesson for me!!




Howard

Did you check the voltage at the connector? Bad voltage in equals bad data back to the PCM. Did you check freeze frame data for that sensor?