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2009 ML280 CDI WDC1641202A511528
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Discussion Starter #1
WDC1641202A511528
ML280CDI RHD
AUSTRALIA
BUILD MAR 09


My A/C won't blow cold. Indie says the A/C compressor runs on the bench but does not work in the vehicle. He said there is no voltage to the A/C compressor.

l purchased and installed a replacement AAC which is now sending 13.3 volts to the A/C compressor but the compressor is still not operating.

Ground is good for the A/C compressor and the AAC controls operate as normal.

Before l spend any more money can anyone tell me if replacing the A/C Control Valve will solve this problem or is there another more like cause?

The AAC has no trouble codes.
The front SAM is not receiving any data from the AAC which l assume is because the new AAC has not been coded as yet.
 

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2009 ML280 CDI WDC1641202A511528
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Discussion Starter #3
43sqd thanks for the info.

Q1. I stupidly read/erased
the sam-f code# without saving . The description read something like "No data received from AAC control unit" with Autel MaxiAP200. The code# has not returned in subsequent restarts.
Q2 Re-read codes today. No AAC code#s.
I will re-install the original AAC and apply your appended advice.
Thanks,
rbotj
 

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2009 ML280 CDI WDC1641202A511528
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Discussion Starter #4
Correction:
Q2 0n second restart l now have dtc 9006 - Component 'A9 (A/C compressor)' has Short circuit.
Should l replace the control valve or the entire A/C compressor as Indie says compressor operates on bench?
rbotj
 

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Please, the first thing you must do is update your profile to include the year, model, is it gas, CDI or Blue and where you live, which tells us you have right or left hand drive.
 

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Registered
2009 ML280 CDI WDC1641202A511528
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8 Posts
Discussion Starter #6
Please, the first thing you must do is update your profile to include the year, model, is it gas, CDI or Blue and where you live, which tells us you have right or left hand drive.
Profile update completed.
 

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2009 ML280 CDI WDC1641202A511528
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8 Posts
Discussion Starter #8
I did but your system is not saving the profile information consistently. I think it stuck this time.
I have decided replace the a/c compressor with the exact same Denso unit and this should resolve the problem.
Thanks for your input.
rbotj.
 

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2009 ML280 CDI WDC1641202A511528
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Discussion Starter #10
That code does not mean the compressor is faulty.
From what l have found on the forum there are three causes:
1 Poor system ground at ground point W29/2
2 Software in AAC control unit
3 Poor ground at refrigerant compressor
There is also the schottkey diode solution.
I will review all of these before coming back to you.
Thanks for your time.
 
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