My heart stopped for a second......

[NeilP]

I stopped by the coffee stand this morning to grab a cup. I pulled around the building and stopped in the parking lot to make a phone call. I turned the engine off and a couple seconds later just happened to glance at the gauges on the infotainment screen which hadn't powered down yet. I darn near had a heart attack when I saw the coolant temp gauge. I started the engine and the gauge immediately returned to 199° . Most likely it is something that I've just never noticed before, but it is interesting that I just rec'd the new OTA update two days ago.

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[2nd 392]

I stopped by the coffee stand this morning to grab a cup. I pulled around the building and stopped in the parking lot to make a phone call. I turned the engine off and a couple seconds later just happened to glance at the gauges on the infotainment screen which hadn't powered down yet. I darn near had a heart attack when I saw the coolant temp gauge. I started the engine and the gauge immediately returned to 199° . Most likely it is something that I've just never noticed before, but it is interesting that I just rec'd the new OTA update two days ago.

Startled when mine just started doing that too, the temp guage on the dash reads normal. After the initial panic I tested it a couple times and it now does it on shutdown consistently. Will bring it up at the next dealer trip if it continues.

 

[NeilP]

Startled when mine just started doing that too, the temp guage on the dash reads normal. After the initial panic I tested it a couple times and it now does it on shutdown consistently. Will bring it up at the next dealer trip if it continues.

Did you recently get the FCA-MY24.U29.44-PROD OTA update as well?

 

[2nd 392]

Did you recently get the FCA-MY24.U29.44-PROD OTA update as well?

Don’t know, I have a 21, haven’t seen anything it just started doing it a couple days ago- but the timing with yours is mighty coincidental.
Hopefully others will report.

 

[alphawolff]

I stopped by the coffee stand this morning to grab a cup. I pulled around the building and stopped in the parking lot to make a phone call. I turned the engine off and a couple seconds later just happened to glance at the gauges on the infotainment screen which hadn't powered down yet. I darn near had a heart attack when I saw the coolant temp gauge. I started the engine and the gauge immediately returned to 199° . Most likely it is something that I've just never noticed before, but it is interesting that I just rec'd the new OTA update two days ago.

You want to know why?

418F is the default reading when voltage is removed from the sensor. The PCM is seeing near 0v on the return circuit, so it maxes out at this temperature. You can reproduce this by unplugging the coolant temperature sensor and checking the temperature again.

The radio is simply reading that output. It's just programmed so poorly that they didn't think of this scenario (that someone would look at the temperatures after turning the engine off), or broke something with a recent update. It should recognize a key off scenario and default to a last-known value, but it doesn't. Expect it to be fixed...eventually.

A dealer visit would not be able to fix this, so don't worry about it.

 

[NeilP]

You want to know why?

418F is the default reading when voltage is removed from the sensor. The PCM is seeing near 0v on the return circuit, so it maxes out at this temperature. You can reproduce this by unplugging the coolant temperature sensor and checking the temperature again.

The radio is simply reading that output. It's just programmed so poorly that they didn't think of this scenario (that someone would look at the temperatures after turning the engine off), or broke something with a recent update. It should recognize a key off scenario and default to a last-known value, but it doesn't. Expect it to be fixed...eventually.

A dealer visit would not be able to fix this, so don't worry about it.

Good info! Thank you.

 

[Maverick909]

it should just line out like the transmission temp once engine is off. ive also see temps climb upwards of 25-40 degrees after shutting down the engine in my 76. since those always read temp via a none electronic sensor. Temps will go up just a bit after shut down and no coolant being pumped to cool it down

 

[bugnuker]

You want to know why?

418F is the default reading when voltage is removed from the sensor. The PCM is seeing near 0v on the return circuit, so it maxes out at this temperature. You can reproduce this by unplugging the coolant temperature sensor and checking the temperature again.

The radio is simply reading that output. It's just programmed so poorly that they didn't think of this scenario (that someone would look at the temperatures after turning the engine off), or broke something with a recent update. It should recognize a key off scenario and default to a last-known value, but it doesn't. Expect it to be fixed...eventually.

A dealer visit would not be able to fix this, so don't worry about it.

Cool info, makes sense.

Why do you think the dash gauge shows normal but off-road pages does not? I works guess it's the same sensor, and maybe there is some logic to use the last recorded value before voltage goes to zero?

Seems like whatever they are doing for the dash, they should copy for off road pages

 

[alphawolff]

Cool info, makes sense.

Why do you think the dash gauge shows normal but off-road pages does not? I works guess it's the same sensor, and maybe there is some logic to use the last recorded value before voltage goes to zero?

Seems like whatever they are doing for the dash, they should copy for off road pages

Different applications, literally. The guy who programmed the off-road pages came before the guy who programmed the uconnect 5 interface. The second guy didn't think about it.

You'll notice a lot of the uconnect 5 software is VERY buggy compared to the older uconnect 4 setup. Random restarts, freezes, audio drop outs, etc. It's hit or miss. It's really bad on the grand cherokees/wagoneers. They've been outsourcing a lot of the software programming these days.

 

[kah.mun.rah]

Actual concern or an opportunity to flex a photo of your 2024 screen?

 

[Heimkehr]

I turned the engine off and a couple seconds later just happened to glance at the gauges on the infotainment screen which hadn't powered down yet. I darn near had a heart attack when I saw the coolant temp gauge.

Maybe this will convince you to use genuine Mopar OAT coolant, and not that Supertech nonsense purchased at Wal-Mart...

 

[NeilP]

Maybe this will convince you to use genuine Mopar OAT coolant, and not that Supertech nonsense purchased at Wal-Mart...

Since I have less than 3000 miles on it from the day I drove it off the dealers lot, I assume that it has the genuine Mopar coolant in it.

 

[Signaljeep]

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