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Air temp actuator/HVAC controller problem


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I've already posted this question over in the cadillac owners forum but I thought I might try here too.

The passenger air temp actuator stays on hot all the time, no matter what temp you set at the HVAC controller. The actuator is a new ACDelco part (there was no actuator there at all when I got the car, so I'm guessing that this problem has been there for a while).

Long story short: I have a GM Tech 2 clone. I can recalibrate the air actuator door(s), and can get each door to respond to a command to go to the hot or the cold position – except the passenger door does the opposite to the command (command it to go to hot on the Tech 2, and the actuator moves to the cold position etc).

 

Also, you can see what voltage is going to the actuators on the Tech 2. While the others are pretty consistant, the passenger side actuator voltage shows about .61v and then 4.8v and back, every 2 seconds or so.

You can't buy a new HVAC controller, so I bought a used one. It works kind-of the same. I got it to work the first time I plugged it in – for the cold half of the range (15C to about 24C), but the actuator wouldn't move any further. Once I unplugged it (to try the old controller again, it didn't do anything different to before) and then plugged the replacement controller in again, the actuator wouldn't respond to temp changes at the dial at all. Just like the original controller.

I can't keep on buying HVAC controllers in the hope that I get a good one, but it's made me wonder. Has anyone here ever had to replace a controller that was faulty, with problems like I just described? I am starting to think maybe it is not the controller.

The only thing left is to check the wiring for a break or poor connection. I have already checked the earth point at C200. 

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Does the door itself move if you move it manually with the actuator rod off?   Is the door itself binding?

Because the actuator was removed, its possible that it is not properly adjusted.  

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

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4 hours ago, BodybyFisher said:

Does the door itself move if you move it manually with the actuator rod off?   Is the door itself binding?

Because the actuator was removed, its possible that it is not properly adjusted.  

The door is a little stiff, but I can still move it by hand (just). The adjustment is actually done with recalibrating the actuators with the Tech 2.

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Seriously consider that the door is too stiff for the actuator to move it based on your statement (stiff).  What does (just) mean?

When I say calibrate I mean, because it was out.  Some actuators have rods that go between the actuator and the door that are adjustable in length.  Maybe the length was changed?  

Have you tried to operate the actuator with the rod disconnected to see if it travels the full length.

There is a commanded position and an actual position readout on the Tech2, how do those line up?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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On 5/6/2017 at 8:20 AM, BodybyFisher said:

Seriously consider that the door is too stiff for the actuator to move it based on your statement (stiff).  What does (just) mean?

When I say calibrate I mean, because it was out.  Some actuators have rods that go between the actuator and the door that are adjustable in length.  Maybe the length was changed?  

Have you tried to operate the actuator with the rod disconnected to see if it travels the full length.

There is a commanded position and an actual position readout on the Tech2, how do those line up?

It means that I can't turn it by hand very easily - in fact, I use a spanner to move it so that the actuator lined up when I fitted it. Using the spanner though, there was no point at which the shaft was binding – the effort to move it was the same though the arc of movement. Is that not how it should be for our cars? Can you spray something like WD-40 onto the shaft to free it up, or must you take it apart? Not looking forward to that.

Commanded position and actual position – well, it's saying commanded is .61v, actual 4.83v. Sometimes the actual voltage fluctuates between 0.61v and 4.83v every 2 sec or so. 

I've been using ALLDATAdiy and I have found a step in trouble shooting this problem that I had somehow missed – checking the operation of the two solar sensors and the four air duct temp sensors. Also the inside air temp sensor. This last item has been getting noisy of late so it might be the cause of the problem. I'll pull it out and lubricate it, but I can't see how it would affect the one actuator temp. More likely a solar sensor or duct temp sensor.

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The doors wont flop around...but they should move fairly easily. Sometimes they can get warped. 

 

Here is the GM calibration service info.

 

Actuator Recalibration 
Calibration Procedure with a Scan Tool
Use the following steps to perform the calibration update:

Install a scan tool. 
Turn ON the ignition, with the engine OFF. 
With a scan tool, select Instrument Panel Module. 
Select Special Functions. 
Select Miscellaneous Test. 
Select Recalibrate all Motors. 
Select ON, wait 30 seconds. 
All counts will display zero and slowly the scan tool will begin to show counts. 
Calibration Procedure without a Scan Tool
Turn OFF the ignition. 
Remove the battery positive voltage circuit fuse of the Instrument Panel Control Module. 
Important: The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds. 

Wait 60 seconds. 
Install the fuse. 
 

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54 minutes ago, Logan said:

The doors wont flop around...but they should move fairly easily. Sometimes they can get warped. 

 

Here is the GM calibration service info.

 

Actuator Recalibration 
Calibration Procedure with a Scan Tool
Use the following steps to perform the calibration update:

Install a scan tool. 
Turn ON the ignition, with the engine OFF. 
With a scan tool, select Instrument Panel Module. 
Select Special Functions. 
Select Miscellaneous Test. 
Select Recalibrate all Motors. 
Select ON, wait 30 seconds. 
All counts will display zero and slowly the scan tool will begin to show counts. 
Calibration Procedure without a Scan Tool
Turn OFF the ignition. 
Remove the battery positive voltage circuit fuse of the Instrument Panel Control Module. 
Important: The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds. 

Wait 60 seconds. 
Install the fuse. 
 

I've done the recalibration using Tech 2 numerous times, the actuator still goes to hot.

However, it still does move – all through its range while recalibrating – and also moves to cold when commanded (by the Tech 2) to go to hot and moves to hot (when commanded to go to cold). That suggests that if it is binding, it isn't affecting the movement range of the actuator.

I have not tried directing air to floor vents only. If it suddenly sorts itself out, that might mean that the upper duct air temp sensor has failed. a $5 part. Let's hope so...

Also, perhaps given what you say about the doors becoming warped, this might be at least part of the problem. I'll have a closer look at it. 

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Don't know. Anyway....here is the wiring diagram for the 2003 actuators and IPM....maybe someone was playing in there before and got something crossed.

 

sevilleactuator.jpg

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I think your door is binding and over stressing the actuator to the point of the actuator not being able to move.

Given that the actuator was removed upon purchase, someone has had difficulty with this already.

Something tells me you are going to need to get into the hvac box and fix that door.  I don't think that will be fun, maybe someone has experience with that.

What year is this car?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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12 hours ago, BodybyFisher said:

I think your door is binding and over stressing the actuator to the point of the actuator not being able to move.

Given that the actuator was removed upon purchase, someone has had difficulty with this already.

Something tells me you are going to need to get into the hvac box and fix that door.  I don't think that will be fun, maybe someone has experience with that.

What year is this car?

No the actuator does move when the Tech 2 commands it to. I think it did also when I first plugged it in – straight to the hot position. I tried moving the door by hand tonight – it's possible, but not really easy. Maybe I just have weak hands...

This is a 2003 Seville STS, right-hand drive.

I tried removing the actuator from the door, kept it plugged in, and tried to adjust temp. The actuator didn't move.

I realised that the Tech 2 displays the voltage going to the vent sensors and the 'counts' at the solar sensors. The vent sensors all appear within range, all similar voltages (about 2.8v at each, 18deg C). The solar sensors did not change counts when I shone a LED light on them (garage light on, but fairly dark) or when I covered them with my hand. In each case, (light/dark) did so for 15sec or more.

So I am running out of options here. It might be the solar sensors failing (I doubt it, or why is it just the pass side with problems?). 

The only thing kind-of worked was when I first plugged in another HVAC controller; it actually responded to temp change commands (up to a point) the first time I plugged it in. It makes me wonder if that might be the problem or the wiring (but I checked continuity, had plugged and unplugged both HVAC controllers trying each of them several times).

The other thing that might point to the controller is that the commanded voltage shown on the Tech 2 does, intermittantly, fluctuate, between the minimum and maximum voltage. Then at other times it stays at the minimum voltage, doesn't change. The left actuator voltages also run opposite all other actuator voltages; they display minimum/maximum positions as low/high voltage readings, while the left actuator shows high/low (eg all others show min 0.61v to max 4.83 while the left actuator is 4.83v to 0.61v. The fact that when the Tech 2 commands the HVAC controller to move the actuator to hot, and it goes to cold (and vice-versa) also suggests maybe the HVAC controller has a fault. I checked the wires at the actuator and no-one's gone in and mixed up their positions in the connector.

These guys offer rebuilt HVAC controllers. Tempted to call them and ask how they 'rebuild' them (generally speaking) to see if it's worth considering buying one.

https://www.autoecmstore.com/collections/ac-heater-control/products/9354046

Very close to giving up now. I've checked everything that the ALLDATAdiy service manual says to. Everything is clear, except the odd voltages described above, and ALLDATA don't mention such a problem

Edited by rhdsts
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Ok, from your post, I get that you removed the actuator from the door to eliminate any possibility that it is door related and the actuator still does not move correct?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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6 hours ago, BodybyFisher said:

Ok, from your post, I get that you removed the actuator from the door to eliminate any possibility that it is door related and the actuator still does not move correct?

Yes that's right, the actuator does not move when you adjust temperature at the HVAC control even when not connected to the door (EXCEPT when commanded to move by the Tech 2. Just like when it is attached to the door). Except with the replacement HVAC controller, the first time that I plugged it in. The actuator (which was attached to the door) moved on command, up to half way from cold. I think it went back to cold as well, on command. I didn't imagine it. But whatever bit of magic that allowed it to half-work then hasn't allowed it to since.

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So the Tech2 controls it via the service connector but you can not control it.by the temp control in the HVAC control, to be clear? 

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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1 hour ago, BodybyFisher said:

So the Tech2 controls it via the service connector but you can not control it.by the temp control in the HVAC control, to be clear? 

Yes, that is correct – but the way that the Tech 2 can control it is back-to-front (ie command 'cold', it goes to hot, command 'hot', it goes to cold).

However, I did control the actuator with the temp control in the HVAC control, with the used replacement HVAC control, but it worked only once and only half-way up the temperature scale (so, if it's a 60-90deg F range, it got to 75deg and stopped).

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Hmm, odd that its reversed like that, I am going to page @Logan < and see if he has ideas as to why that is.  

This is a right hand drive, meaning that its a mirror to the US left hand model, your VIN that goes into the Tech2, may not know the vehicle is right hand drive...  (just thinking wild here)

Do you know when and how the car became right hand drive?  Do you have any other oddities?   Although the driver passenger doors would probably be the only issues with a swap of the systems....

Give that a thought.

Your PCM might need a proper flash.

Lets see what Logan thinks he is very knowledgeable about this sort of thing.

Hang in there

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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RHD car? Can that be verified? 

Is it a factory RHD or something like a LHD converted to RHD Australian? 

Some cars....like Mini Coopers....lots of RHD and LHD factory versions for different global markets....well engineered. 

There were a few RHD factory built 1998-2004 Seville /STS cars. For Japan etc.

All cars in Australia must be RHD...So there is a cottage industry there...converting imported LHD cars to RHD. 

Big difference in quality. Picture shows 1994 Seville converted to RHD. Looks great on first glance....but plenty of flaws can be noticed upon closer inspection.

Imagine unseen brackets and wiring inside..

Shifter / knob lock is first flaw.. ...black seatbelts and buckles....I wonder about the wiper arms.

How do you convert the steering rack...brake booster...steering column...brake pedal? Yikes.

 

rhdseville.JPG

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Ok....looking at the GM service manual....there are some differences between factory LHD and RHD. 

That explains why these cars have a center style HVAC case. (center oriented heater core for example). 

Are you checking the correct actuator? More to come...it appears there may be a different HVAC case depending on LHD and RHD. 

Anyway....couple of tidbits seen in the service manual....

#1 is car has to be running for proper calibration..

#2 is a service bulletin

#3 shows center mounted HVAC case.

rhdseville1.JPG

rhdseville2.JPG

rhdseville3.jpg

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Like I said, Logan, would be helpful!

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Trying to sort out the service manual......I think even the service manual guys got confused with the different ones...'left side (RHD)' for example.

Kind of scrambled in with passenger and drivers side repair descriptions.

The instructions seem to be incorrect on a couple of them. 

Update...I think the service manual may have a misprint.....anyway....I attached pics of each one GM ESI shows.

 

 

rhdseville4.JPG

LHDright.JPG

RHDright.JPG

LHDleft.JPG

RHDleft.JPG

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Wow! Thanks Logan! Really appreciate the effort you've gone to.

I have an ALLDATAdiy subscription and I think it is mostly the GM/Helm official service manual. Like you found, the actuator replacement description for RHD is mixed up. I eventually worked it out! 

I found that service bulletin too. Unfortunately my system doesn't overshoot the correct temp and settle, it just never gets off hot :(

I did not know that the HVAC control module could self-recalibrate. I will give that a try.

Otherwise, I am out of options.

I will go ahead and remove the dash top to check connections and resistance of the upper vent temp sensors and the solar sensors ( even though Tech 2 shows that they're all within range). 

Then it's going to be a case of throwing parts at it, hoping one sticks. What I mean by that is, I have already tried a different HVAC control module, but I bought one from a 1998 model and it looked worn. It did work initally, although not through the full range of temperature. So now I'm looking at buying one in better condition from a 2003 or 2004 car (new as possible) or spending a lot of money on the reconditioned HVAC control module.

 

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Good luck with this, that you got it to move briefly is a good sign.  Let us know how it goes

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 4 weeks later...

Hey folks, I am having a similar actuator issue with my 2002 Eldorado. When the car is first started I have good A/C on both sides. However, after the engine warms up and I then adjust temp or mode the doors get out of whack and I end up with heat coming from one side or the other (and sometimes both). I also get current B1340 and B1341 codes when this happens, so I suspect the actuators or the ACM. I opened things up and checked and neither of the actuators moves at all.


I removed both actuators and both are pretty worn - you can move the actuator rod by hand with a moderate effort and it clicks as the gears slip but I don't feel any missing teeth. Both blend doors move easily. The new actuators are solid as a rock, and therein lies my newest problem. Both of my new actuators came with the actuator rod fully to the left stop - way out of the marked normal range and too far away to hook up to the door rods.  The actuators came with a big warning not to apply power without first hooking up the doors or it can go a position that is unrecoverable during normal self-recalibration. Seems like a catch22 when the actuators come all the way to the stops to begin with....I must be missing something obvious or am the unluckiest person alive - because I returned the first two thinking that someone had previously returned them after doing exactly what the warning said not to do. But then the second set (different brand and different source) came the same way. Based on the pictures of all 3 brands of replacement I found (ACDelco, Dorman, TechSmart) this appears to be normal even if it is out of normal operating range.


Unfortunately I don't have a Tech2 - am I up the proverbial creek or is there a way to move these dudes to the normal range for installation? I don't see any way to remove the rod to open up the case and move it manually but that seems sketchy anyway.


And where exactly is the battery positive circuit fuse of the Instrument Panel Control Module located? That is the one in the trunk or the MaxiFuse?


Sorry I am trying a DIY because all the smaller shops I took it to just oohed and ahhed about how complex Caddy HVAC systems are and my dealer wants my firstborn and a blank check to look at it - plus they warned me that if they run into any no longer available ACDelco parts they have to walk away anyway. Something I already experienced with the suspension last fall....


BTW this is LHD


Thanks!

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Sadly I have the same problem with my 97 Deville.

Arm was all the way to the left and barely allowed the rod to even attach.

Then it goes all the way to the right and rips the rod out of the clip.

I will let you know if I get anywhere tomorrow.

Been pretty irritating

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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I ask  you one important question

Was the replacement actuator(s) oem or some aftermarket brand?

Apparently OEM is the only way to go. I went to my local salvage yard today and bought a used oem one and installed it. I then unhooked the battery for 1 minute, hooked it back up, turned the key on for 3 minutes without touching anything. It works perfectly now.

I watched it calibrate normally and had no weird rod issues, no fitment issues. 

All is back to normal

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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