My son's '97 E300 AC stopped working, the error code I get from the CCU is 1416 for the coolant circulation pump. What has that got to do with the AC and why would it stop it from working? Should I just replace the pump or is it fixable? Any input is appreciated.

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Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

Shouldn't be any connection between the two. You only need that pump to get good heat at idle. Doubt that you'd need it in VA...I've lived without mine since I got the car four years ago and I'm in New England.

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14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Thanks Shertex. That's why I'm confused. The CCU code was for the coolant circulation pump, is there another one? Why would it prevent the AC from working? I checked the the 134a pressure and its right at the top. I suppose no heat at idle would be considered a HVAC problem, so there is that connection. When I can I'll read the codes again and see if something else pops up. Thanks again.

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

Just for grins, you might try actually disconnecting the aux water pump and see if that has any effect.

__________________
14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Now that I think about it, when the AWP on my 92 went out for the second time it did have an adverse effect on other dimensions of climate control.

__________________
14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Are you certain 1416 is the the only code you're getting? I would clear codes and see if if comes back.

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CENSORED due to not family friendly words

That was the only code this morning. I cleared it and it came back. The car is not here at the moment so it may be tomorrow before I can read them again. I agree with Shertex, I don't think I need the AWP in my location, I may disconnect and see what happens. We've only had the car a few months.
It had a new compressor and some other AC parts installed about a year ago. The AC worked when we got it. I have receipts for the AC work but again, they are in the car. Thanks for the help.

UPDATE; Got to see the car this afternoon. Checked and cleared the 1416 code again and the AC started working! Not sure what I did right or wrong but for the moment it works. Thanks to everyone for the help.

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

I have the AUX pump unplugged on my 97 SL320 and it has no affect on the AC or any other function. My climate unit is the same as a C230 / C280, is similar to the E320 but mine have less buttons.

I don't see a logical reason to disable the AC by design if the aux pump quits, however, electronics can act very strange when they start to fail.