Rough Idle When A/C On

[mcfarlrm]

Yesterday I noticed a rough idle while sitting at a red light. The A/C was on at the time and when I turned it off the idle returned to normal. About 20 min later, with the A/C back on, I gave it about half throttle from a stop and hesitated to accelerate and jolted at about 4500 RPM. Has anyone else experienced this issue? Looks like there is a TSB to address this issue to reprogram the PCM. I had a recommended fuel injection service done about a week ago and hoping that they didn't screw anything up with the throttle body, fuel rails, injectors, etc.

 

[TXCarbonized]

Did you ever get this figured out? My 2022 seems to idle rough when the AC is on too. When I turn the AC off, it's perfectly smooth.

 

[mcfarlrm]

Issue comes and goes. Of course, dealership/service dept said they couldn't find anything wrong.

 

[TMac]

This is most likely not a big deal. When you're at idle and the AC pump is engaged, it places a load on the engine. Does the RPM drop and not recover? Does the engine "smooth" out after a bit of time? Did they address the TSB?

 

[mcfarlrm]

RPM's would drop and recover and engine would stumble. Haven't really noticed it lately so not concerned anymore.

 

[Hassa]

Yesterday I noticed a rough idle while sitting at a red light. The A/C was on at the time and when I turned it off the idle returned to normal. About 20 min later, with the A/C back on, I gave it about half throttle from a stop and hesitated to accelerate and jolted at about 4500 RPM. Has anyone else experienced this issue? Looks like there is a TSB to address this issue to reprogram the PCM. I had a recommended fuel injection service done about a week ago and hoping that they didn't screw anything up with the throttle body, fuel rails, injectors, etc.

The TSB that fixes this issue is TSB 20-2405. Print it out and bring to the dealer with the complaint of a rough idle with AC on. Reprograming the PCM fixes this issue. It's also the fix for Safety Recall 22S27, so the dealer has two reasons to update the module.

 

[Lightning Struck]

The TSB that fixes this issue is TSB 20-2405. Print it out and bring to the dealer with the complaint of a rough idle with AC on. Reprograming the PCM fixes this issue. It's also the fix for Safety Recall 22S27, so the dealer has two reasons to update the module.

I suppose this would pose an issue if you have a tune though.

 

[mcfarlrm]

AC issue is back again causing engine to stumble at a complete stop. Issue goes away when in park, neutral and when AC button is turned off. Having Ford look into it once I take it back in to get my transfer case repaired. This SUV has had more problems than any other vehicle I have ever owned.

 

[hbalek]

AC issue is back again causing engine to stumble at a complete stop. Issue goes away when in park, neutral and when AC button is turned off. Having Ford look into it once I take it back in to get my transfer case repaired. This SUV has had more problems than any other vehicle I have ever owned.

That reminds me of my 1983 Ford LTD and 1985 Tempo! My ST hasn't done this...Knock on wood!