W210 Climate control question???
 

Just picked up my 1999 E430 yesterday (guess i should probably change my name to Cliff_W210).

It's in great shape, I've got receipts of $9000.00 worth of maintenance preformed by the dealer less than a month before it was traded in.

Only 1 problem, on the drive home I noticed that after switching off the A/C compressor by pushing the econ button, I can't get it to come back on. The only way to get the econ light to go off is by turning on the defroster which blows out max heat? Does anyone have any ideas here? It's probably not going to be warming up here for about another month, but when it does I'm really going to be wanting that a/c.

With the engine running, press and hold the REST button for >5 seconds. Then press the left AUTO button until the display reads 7 on the left. Note the number on the right first with the compressor running, and next with the compressor shut off. Tell us what these read.

I did everything you said, and the number on the right was 03 both with the compressor on/off.

When i pushed the defroster button to turn on the compressor, the econ light never went off.

That number is the high-side refrigerant pressure in bar, and should be quite sufficient.

I should have asked you to record the sensors 1-8 as well. #5 is the evaporator temperature sensor, and I would lay odds on it being unrealistic.

Would it help if I gave you all the number readouts?

Here's what all the readouts are:1-67, 2-58, 3-78, 4-78, 5-73, 6-200, 7-04, 8-78, 9-27, 10-1.5, 11-2.3, 12-43, 20-3.2, 21-42, 22-00, 23-32, 24-13.5, 40-164, 41-85, 42-72, 43-136

Does this mean anything to you? I know that the system has been recently charged with refrigerant so it shouldn't be low.

The sensor values at 9 and up won't kill your AC, so I didn't ask for them. Some of them have absolutely no meaning according to the diagnostic manual; I don't recall exactly which though.

I expected to see a very high value for #5, the evaporator temperature sensor. It is not, assuming that your climate control sensors read in F and it was really about 67F inside the car when you did the test.

The next step is to extract trouble codes from the system. The pushbutton unit can do these also. Here is the procedure:

Ignition ON
Temperature selector left "HI" right "LO"
Within 20 seconds, press REST and EC simultaneously for more than 5 seconds
The LED in the recirculate button flashes and the display shows "di R"
Press AUTO repeatedly until all DTC's (refer to DTC table) are displayed. Record each DTC as it is displayed.

To erase: Only possible after all DTC's are read out. Simultaneously press both AUTO >2 secs. "d" will be displayed in the left side of the display window and "FF" on the right.
To cancel erase: By pressing AUTO the current faults will appear again.

Set the temperature selector to normal setting
Turn the ignition OFF to end test.

Here's an old post of mine with the same issue. The second page gives the fix that worked for me.

Where's the link to the thread?

I'll get the trouble codes today and report back.
Thanks,
Cliff

http://www.peachparts.com/shopforum/showthread.php?t=86110&highlight=economy+light

Guess that would help, wouldn't it? :)

Sorry about that.

So are you saying all i need to do is follow those steps to override the low refrigerant indication?? Or do i also need to replace the refrigerant temperature sensor?

You do need to extract trouble codes from the unit before doing anything else.

gotcha

Cliff - since the temp sensor was only a $30 part at the time, I believed the TSB and replaced it as a matter of course. Then I did the rest of the procedure.

I finally got some free time to try and pull the codes. I got to the point where the recirculation light was blinking but instead of showing Di R it read Eb1 (the b may have been a 6)
It read: Eb1, Fan sign, 241
After pushing auto: E, FF

Those were the only two codes I got.

After clearing it like you said, I turned the car back on and the econ light went off..... But now it blows Ice cold out the passenger side and plain Econ out the Driver side vents.

Ideas?