[Solved] PowerBoost AC stops when vehicle stops

[23PB&Me]

Hi All, with the warmer weather I have been using my PowerBoost’s AC a lot more and discovered a behavior that has really been bothering me. I took it into the dealership for standard maintenance and told them about this, they said they were doing a TSB but nothing changed. I have searched online for a couple of days but can’t find my specific issue.
—-
State 1: engine on, AC works fine. As the system charges the air gets cold, freezing freakin cold

State 2: engine off(battery), ac doesn’t work. As soon as the engine kicks off and the truck goes to battery mode the air starts getting warm until it is hotter than the outside temp. It starts getting that humid AC just turned off smell. Fan speed does not change.

Then back to state 1 when the engine turns back on. Think stop and go traffic or suburb driving with red lights.
—-

From my research:
1) The power boost’s AC system should be driven by an electric pump off the hybrid battery. So there should be no dependency on the engine being on. The service advisor said it runs off the engine. Which is it for the 2023 powerboost?

2) There is a condenser freezing issue out there, symptoms include diminished air flow. This is not the case, air flows as expected and behavior reverts as soon as the engine comes on.

3) There is an issue where the mix valve gets stuck on hot. This can’t be the case since it starts working as soon as the engine kicks on and the temp fades cold/hot/cold.

4) There is a TSB out there. My service advisor said he knew about it and that it reprograms the climate control unit to keep the truck engine on during AC use. The engine still turns off during max AC, so either they didn’t do the update or he didn’t understand what it did.

This is a major pain since remote start doesn’t cool the truck and with the hybrid function it takes longer to cool the truck once you start driving since it turns off at lights and such.

Any help/feedback/advice you could offer would be greatly appreciated.

Thanks in advance!

-Kyle

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[Antimatter22]

I wouldn't think the '23 would be different than my '22 but my AC works whether the engine is running or not. I don't have much faith in what the technicians and service managers actually know about the products they're supposed to service. Wish I had suggestions for you but that doesn't sound right to me.

 

[Samson16]

The AC compressor runs off high voltage from the HVB. Are you sure you have a PowerBoost?

 

[Hans Moleman]

The AC compressor runs off high voltage from the HVB. Are you sure you have a PowerBoost?

the truck in his avatar has a PB door badge so I sure hope so

but for the OP, yeah the A/C still should still work in EV mode.Although the A/C compressor runs on the HVB, I wonder if you have a bad 12v battery which causes weird issues.

 

[wessermgm]

I wouldn't think the '23 would be different than my '22 but my AC works whether the engine is running or not. I don't have much faith in what the technicians and service managers actually know about the products they're supposed to service. Wish I had suggestions for you but that doesn't sound right to me.

In my '24 the AC works in electric mode. There is a clear issue here.

 

[Samson16]

the truck in his avatar has a PB door badge so I sure hope so

It's also a great looking truck and his name is Kyle so let's help the man!

I would get in the truck and turn it on (brake/start). Verify RPM reading around 1300. Turn the AC on auto 3 LEDs non recirculating dialed down to 63 degrees and after several minutes of cold air stick my instant read thermometer I use for grilling into the vent opening just an inch or so. Take a reading(pics are great for evidence). Wait till the ICE cycles off and the RPM drop to zero, then take another reading once you can feel that clammy warming start(pic please). There should be no change or warm clammy non-conditioned air feeling. Something is wrong.

 

[23PB&Me]

The AC compressor runs off high voltage from the HVB. Are you sure you have a PowerBoost?

100% sure it is a PB

 

[23PB&Me]

It's also a great looking truck and his name is Kyle so let's help the man!

I would get in the truck and turn it on (brake/start). Verify RPM reading around 1300. Turn the AC on auto 3 LEDs non recirculating dialed down to 63 degrees and after several minutes of cold air stick my instant read thermometer I use for grilling into the vent opening just an inch or so. Take a reading(pics are great for evidence). Wait till the ICE cycles off and the RPM drop to zero, then take another reading once you can feel that clammy warming start(pic please). There should be no change or warm clammy non-conditioned air feeling. Something is wrong.

Thanks, I'll give that a try to get clear evidence, probably vid the whole thing so I can give it to the service department in case they "can't see the problem"... *eyeroll* I have a logging temp probe that I use for longer smokes, I can capture every detail for us

 

[23PB&Me]

the truck in his avatar has a PB door badge so I sure hope so

but for the OP, yeah the A/C still should still work in EV mode.Although the A/C compressor runs on the HVB, I wonder if you have a bad 12v battery which causes weird issues.

I hope it isn't bad yet, truck is only 6 months old. maybe I'll try the BMS system reset to see if that changes anything before taking it back to the dealer.

 

[Samson16]

I just tested mine and no difference engine on or off. Low eventually dropped down to the mid 40’s at the vent. It kept dropping from start up with ICE off then on (battery char

 

[Samson16]

Partial post there but my point is that you should not notice a difference ICE on/off

 

[23PB&Me]

Thanks to everyone for the advice so far! I did the logging and got almost exactly what I had described. Yellow is the vent temp, blue is the cabin temp, green starts outside then gets pulled inside. I did video for 20 minutes so if you really want to bore yourself and listen to me sweat I can post that, but the log image and description should be sufficient. I'll break it into stages and behaviors. Times are rough for the description, but I do have exact stamps in the video that I'm working off. I probably should get that ODB logger a lot of you guys have, been eyeing that for a while, then I could directly overlay the temp and engine status behavior.

Before I dive into the details, in the 6th section I did have a surprise, I forced the engine to idle for 2 minutes but the temps did not drop, so maybe it isn't engine on but vehicle moving? I will need to get more data on that, moving in EV and stopped in IC.

Driveway Idle: 2:07-2:11, 4 minutes
stayed in EV mode the whole time, set temp to 63 and fan speed to 5. Temp in the vent dropped initially but only made it down to 90 degrees, I think it might have been due to a drive I took about an hour earlier. Then the temp bounced between 95 and 105 in the vent, cabin temp was over 100.(this is about how I find my truck after 5-10 minutes of remote start).

Driving: 2:11-2:13, 2 minutes
It got too hot and I needed AC so I started to drive. at the video 4 minute mark I leave the driveway, at 4:28 the vent temp peaks at 107 then rapidly drops, 79 after 1 minute, 65 after 2 minutes.

Stopped at light: 2:13-2:14, 2 minutes
As soon as I stopped the truck went into EV and within 30 seconds the temps started climbing from 62 up to 75 in 50 seconds.

Driving 2:14-2:15, 1 minute
After 20 seconds of driving the temps started to drop and went from 75 to 66 in one minute

Safeway EV Idle: 2:15-2:21, 7 minutes
As expected shortly after the engine went to EV the temp started to climb from 66 to 82, then there was a click/clunk noise and the temp went from 82 to 78 before climbing back up. I'm assuming the click/clunk noise is related to the AC system on due to the timing before the cold air. It then climbed to 96 when another click/clunk was heard and another short drop followed. I captured the noise in the video attached, it happens right after the temp hits 96.0 in the upper left read out. very shortly after the temp drops from 96 to 86. I decided to put it in max AC for grins and giggles, still in EV mode the temp climbs right back up and starts to level to just over 100.

Safeway forced IC idle 2:21-2:24, 2 minutes
To see if engine on would help I forced idle for a while(video:15:28-17:34) and a surprise to me the temp did not drop as expected. it stabilized out around 102 before I had enough and had to start driving.

Driving: 2:24 - end
When I stopped forcing idle the truck went back to EV and a few seconds after moving there was another clunk(Since the engine wasn't on I could hear it), then the engine kicked on for driving and the vent temp dropped to 50 in a couple minutes. that is when I stopped recording video. The larger time log shows another blip up around 2:40 where I got stuck in stop/go traffic and the vent temp went up to 60, then we started moving again and the vent temp stabilized at 46 for the rest of the drive.

Thanks again for the attention to this thread and helping me!

-Kyle

 

[Ford Motor Company]

Hi All, with the warmer weather I have been using my PowerBoost’s AC a lot more and discovered a behavior that has really been bothering me. I took it into the dealership for standard maintenance and told them about this, they said they were doing a TSB but nothing changed. I have searched online for a couple of days but can’t find my specific issue.
—-
State 1: engine on, AC works fine. As the system charges the air gets cold, freezing freakin cold

State 2: engine off(battery), ac doesn’t work. As soon as the engine kicks off and the truck goes to battery mode the air starts getting warm until it is hotter than the outside temp. It starts getting that humid AC just turned off smell. Fan speed does not change.

Then back to state 1 when the engine turns back on. Think stop and go traffic or suburb driving with red lights.
—-

From my research:
1) The power boost’s AC system should be driven by an electric pump off the hybrid battery. So there should be no dependency on the engine being on. The service advisor said it runs off the engine. Which is it for the 2023 powerboost?

2) There is a condenser freezing issue out there, symptoms include diminished air flow. This is not the case, air flows as expected and behavior reverts as soon as the engine comes on.

3) There is an issue where the mix valve gets stuck on hot. This can’t be the case since it starts working as soon as the engine kicks on and the temp fades cold/hot/cold.

4) There is a TSB out there. My service advisor said he knew about it and that it reprograms the climate control unit to keep the truck engine on during AC use. The engine still turns off during max AC, so either they didn’t do the update or he didn’t understand what it did.

This is a major pain since remote start doesn’t cool the truck and with the hybrid function it takes longer to cool the truck once you start driving since it turns off at lights and such.

Any help/feedback/advice you could offer would be greatly appreciated.

Thanks in advance!

-Kyle

Hi there, Kyle. This AC concern doesn’t sound like something we want you to experience with your F-150. Could you please send us a PM with your VIN and the name and location of your Ford dealer? I'd be happy to look into how I can assist you on my end. To send a private message, just click on our username and select "Start Conversation".

 

[23PB&Me]

Update for anyone following this.

I bought an OBDLink MX+ to do some logging and found some PIDs that showed a little more info to the problem. See attached for some mediocre log analysis.

PIDs found useful
SAE PID: Engine RPM
SAE PID: Vehicle Speed
Air Conditioning Control Module: Electric Air Conditioning Compressor Speed(RPM)
Air Conditioning Control Module: Electric A/C Compressor High Voltage Supply(V)
Air Conditioning Control Module:Compressor / Motor Current (A)
Heating, Ventilation and Air Conditioning Control Module: Eternal Ambient Temperature (C, F)
Heating, Ventilation and Air Conditioning Control Module: Evaporator Temperature (C, F)

Findings:
1) AC Compressor RPM and Current drop to 0 resulting in an increased Evaporator Temperature and increased vent temp
2) Compressor RPM and Current drop does not correlate to engine RPM(20240624_122423 has a section where the truck is stopped, RPM is 0, and the AC system turns on briefly then shuts off multiple times)
3) Compressor RPM and Current drop has a correlation to MPH = 0(20240622_172356 has a long run period where RPM doesn't drop to 0, not all MPH stops drop the AC system but all stops do affect the Compressor Current in that log(need to do more analysis to find this in other logs))

Would someone mind logging the PIDs above and sharing a log from a truck behaving normally?

-Kyle

 

[Snakebitten]

I'll try to get some time in the next couple of days and load your PID suggestions.
Note that the 2022 (my truck) has a very different enhanced Ford/Lincoln/Mercury PID library than the 2023.
Ot at least it did until the very recent OBDlink update (Android). I don't know what all changed in the update, but it's a major version upgrade and they even stated so.

Regardless, I'll load the PIDs and watch for what changes (or doesn't) when ICE is off vs on. As everyone mentioned, the AC in the Powerboost isn't supposed to be diminished in any way with the ICE off.
I spend many hours in my truck as an office. The HVAC is my second most favorite thing about the truck! It's fantastic.

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