HVAC - Defroster Motor - help....

[ianward]

I noticed recently that the positioning motor which adjusts the air flow up to the windscreen wasnt working, after a fault code scan i got the following:

Potentiometer On Positioning Motor for Defroster Flap
Adaptation Limit Surpassed

cleaned and lubed up with WD40 all the linkages etc, ran through the output tests and you can see the motor open the flap when it moves from one extent to another, but the fault code wont go away - still the same fault (much as i expected)

so this week i bit the bullet and bought a brand new motor from TPS ~£80, plugged in and I am still getting the same fault? - it is the right motor i have replaced (the one with the green linkage on, part number ending "B") but the fault code is still the same and i still cant direct air up to the windscreen...

Has anyone any suggestions as to why this would be happening?

I really need to get this sorted as its a pain driving down the motorway in the rain and the screen starts to fog up not an ideal situation by far

Many Thanks - Ian

[nevo]

Yes its the green one,take the glovebox out again and take the motor off and operate by hand see if you get full blast on the screen,if ok put aircon on man and off,leave the motor hanging on its wires,make sure it fully closes,close the lever fully.You may have got it slightly out if sync, did you get a moter number on the fault code?

[ianward]

Have moved it manually with the motor off and I get full flow on the screen, will try switching econ mode on and off as well as the OFF button, will scan again in the morning and put the full code on, just been speaking to someone who said it could be the controller that is faulty - hope not as I don't think will be cheap

[nevo]

Just want you to pair the motor and lever when they're both fully closed before you re-connect,see what happens wheh you press the heated defrost button on the bottom of the controller.

[ianward]

I scanned the car again this morning and this is the fault code:
1 Fault Found:
00727 - Potentiometer in Positioning Motor for Defrost Flap (G135)
09-00 - Adaptation Limit Surpassed

I then unplugged all the motors and pressed all the buttons on the controller to direct air up/down/middle/recirc etc.... and scanned again:

4 Faults Found:
00727 - Potentiometer in Positioning Motor for Defrost Flap (G135)
30-00 - Open or Short to B+
00727 - Potentiometer in Positioning Motor for Defrost Flap (G135)
09-00 - Adaptation Limit Surpassed
00601 - Potentiometer On Positioning Motor for Central Flap (G112)
30-00 - Open or Short to B+
01841 - Potentiometer/Actuator for Temperature Flap: Left (G220)
30-00 - Open or Short to B+
I expected to get the open faults as they were all unplugged, reconnected everything and cleared the faults, but still getting:

1 Fault Found:
00727 - Potentiometer in Positioning Motor for Defrost Flap (G135)
09-00 - Adaptation Limit Surpassed

I unplugged all the connectors off the back of the controller (5 plugs) plugged everthing back in scanned and still the same adaption limit surpassed fault....

Does this point to the controller - or am i missing something simple... sure hope so - what ever I do just cant get the defroster flap motor to move...

Thanks - Ian

[nevo]

G135 is indeed the pot inside the motor not the motor itself,might be worth checking the connector and wiring,also try a post on vcds on adapting the new actuator.Does it open the lever partially?

[ianward]

when i plugged the motor in at first it did move, but only to the fully closed position and there it stays, will have a look for a wiring diagram to check outputs, will try a post on vcds as you suggest...

Thanks again - Ian

[ianward]

plugged the original motor back in and ran output tests... nothing - dead? plugged new motor in - same fault code, but at least moves on output tests, just unplugged the connector whilst the flap was in the open position which will get me by for the minute until i can get this problem sorted out - really strange

[nevo]

Here's something to try get the old motor,if you look round the edge you will see 6 plastic clips,carefully unclip them,it may be easier to break 2keeping 4 to reassemble,part the two halves,lubricate the plastic gears,reassemble and try it again(usually they just stick,the motor is usually ok)just wondering if the new motors pot is faulty.

[ianward]

possibly, but would that "00727 - Potentiometer in Positioning Motor for Defrost Flap (G135) 09-00 - Adaptation Limit Surpassed" still show as a fault even with no motor plugged in, i would expect the open circuit fault, but the other should have cleared i would have thought - will give it a try to strip the motor down and have a look...