[BoltSD]

The wife pulled too far into traffic, and a passing car clipped the front end, ripping off the lower grille and license plate holder. I took it to my regular bumper repair guy (I hate that I have a guy for this), and he did a great job of cosmetically fixing the front end (mostly a few scratches on the front end) and installed a new grille. Immediately afterwards, we have had a persistent service indicator with the following two messages: 1. Icy conditions possible, drive with caution, and 2. Pedestrian Friendly Alert Function.

The temps are in the 60s, so I know the message is erroneous. Moreover, the car is still emitting the pedestrian noise as usual. The warning messages were not present immediately after the collission or in the few days we drove it before tthe repairs were done. I'm thinking there must be two connections somewhere on the front end which are now disconnected?

If anyone can shed some light on this, it would be greatly appreciated. I intend to have the bumper guy take another look in a couple days, and it would be great to have some idea of what to look for.

 

[drdiesel1]

What is the outside air temp reporting ? Sounds like the OAT sensor might have an issue.
You'll need a capable scan tool to read DTC's to know more.

 

[BoltSD]

I took another look, and I don't see the temp anywhere, which again suggests to me that something is disconnected. On a lark, I connected a Bluetooth OBD2 scanner and a generic code reader app, and I could see tthat it is registering 2 faults, one of which is temperature sensor related. In fact, I was actually able to clear the fails with the app, but they came back within a few seconds. We're going to pull the bumper Thursday to see if there is something disconnected.

 

[Packard V8]

I had a similar problem after a repaint of a very minor scrape on the rear bumper. My paint and body guy forgot to reconnect a wiring plug. Fortunately, it was easy to see and do at home.

jack vines

 

[BoltSD]

I'm fairly certain this simply a loose wiring harness somewhere in the front of the car. I'm thinking when he pulled the old grille off, it probably disconnected then and there, and he simply didn't know that something had to be connected. I'll update after we take it apart tomorrow.

 

[BoltSD]

Turns out the body shop discarded the ambient temperature sensor when they removed the remnants of the damaged lower grille. It is located right at the bottom. Thankfully, it is only a $7 part. Interestingly enough, even after replacing it, we were still getting the icy conditions warning, and instead of no temperature display at all, it was now showing -40. I managed to clear the yellow dash warning with an obd2 reader and an app, and the Pedestrian Friendly warning, but the -40 was persistent, which also was messing with the HVAC system (impossible to get any AC regardless of settings). Our last desperation act was to disconnect the 12v battery for 30 seconds, and that did the trick!

Hopefully, this post might prove helpful to someone else who has seemingly unrelated symptoms caused by a faulty or missing ambient temperature sensor.

 

[drdiesel1]

Yes, the OAT sensor isn't an instant update PID. A reset is required for an on demand update.
By disconnecting the battery it reset the module. We do it with the scan tool.

Or you can just wait for it to update on it's own.

 

[BoltSD]

With temps pushing 80 and the HVAC only pumping out heat, waiting for it to update on its own wasn't an option. Did I mention this is my wife's car? As is my typical response, I do whatever it takes to make the complaining stop as soon as possible!

 

[dbostrom]

That's an interesting hint about the possible peripheral involvement of the front camera in pedestrian safety functions. Did you get that fault cleared?

 

[BoltSD]

Yes, all faults are gone. I'm thinking both are on the same wiring harness, and almost like an old set of Christmas lights, the missing ambient temp sensor somehow messed with continuity. At no point did the car stop making the pedestrian sound, which made the error message that much more confusing.

 

[dbostrom]

Thanks BoltSD. I was confused (as so frequently), thought you were referring to the driver-don't-run-down-pedestrian warning system, not pedestrian-stop-looking-at-fone sound.

Still, useful to know that the rest of the car depends somewhat on that particular temperature sensor and that it's not only for there for display purposes. Somehow I'd imagined a separate thermistor for the rest of the gear.

 

[ChevyBolt25]

I had a similar problem after a repaint of a very minor scrape on the rear bumper. My paint and body guy forgot to reconnect a wiring plug. Fortunately, it was easy to see and do at home.

jack vines

Would you kindly please take a picture of where the sensor is? And how to access it? Thank you very much for your help.

 

[BoltSD]

Would you kindly please take a picture of where the sensor is? And how to access it? Thank you very much for your help.

Sorry, I wasn't there when he put everything back together, so I'm not sure.

 

[GJETSON]

Would you kindly please take a picture of where the sensor is? And how to access it? Thank you very much for your help.

Sadly, it pops into a hole in the center of the lower grill, from the back.

https://d354nuoz4t18d4.cloudfront.net/images/15de21c670ae7c3f6f3f1f37029303c9/c0b5ac005acd4e203333e3f9ac28770b.jpg?cb=1566513181

https://dz310nzuyimx0.cloudfront.net/strapr1/06a7772b3c57be922d9154c7dd4e3700/57da88b31384858775735e3296498a32.png

https://dz310nzuyimx0.cloudfront.net/strapr1/fe079c172e1dbd5f9872d390c41a86f1/6a045826e145ea19a89db85d44a54219.png

I am pretty sure the entire front-end need to come off to access it.

 

[GJETSON]

I had a similar problem after a repaint of a very minor scrape on the rear bumper. My paint and body guy forgot to reconnect a wiring plug. Fortunately, it was easy to see and do at home.

jack vines

Dang Jack! You must have incredible long, skinny fingers to get through those narrow grill louvers to attach a plug.

OK. I just went out and tried it. I can get my fingers back in there to feel the back of the plug. Do you build ships in a bottle for a hobby?

 

[GJETSON]

You can see the round, black sensor in the center of the bottom louver.

 

[GConary]

Got the same error messages today after going through a car wash. Possibly shorted from the water?? Any easy fix? It does look inaccessible without removing the entire front grill.