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Mercedes Compressor quits soon after startup

djmacc on Sun June 15, 2008 2:26 PM User is offline

Year: 1998
Make: Mercedes
Model: E 320
Refrigerant Type: 134-A
Pressure High: 42 psi
Country of Origin: United States

My wife has a 1998 E 320 and as it warmed up this spring I noticed that the A/C only works when you first start up the car. When it quits blowing cool air you have to shut the motor off and then restart and usually it will blow cool for a while maybe 3 or 4 minutes. The fan works fine in side the cab and the controls all seem to work fine. When it blows cool it seems to be very cool. If you shut off the car remove the key and restart the car the compressor comes on immediately. The twin A/C fans come on as well. At first they come on at high rpm and soon afterward they slow down a bit until the compressor quits and then they shut off as soon as the compressor quits. There is no unusual noise coming from the clutch or anything else. So what do you guys think.

-------------------------
1998 Mercedes e320

Matt L on Sun June 15, 2008 3:10 PM User is offline

When the system quits, press and hold the REST key on the pushbutton unit for >5 seconds, until the display changes to read "1" on the left side and a sensor value on the right. Press the right AUTO key to rotate through the list and write down the values.

Next, turn the engine off and turn the key to position 2 (don't start the engine).
Set the temperatures, 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 are displayed. Record each DTC as it is displayed.
To erase: Only possible after DCT's are red out. Simultaneously press both AUTO > 2 secs. The display will read "d" and "FF" on the two sides.

The information derived from these tests will probably tell what is wrong. It's likely the evaporator temperature sensor, but the above procedure will show for sure.

djmacc on Sun June 15, 2008 9:32 PM User is offline

Quote
Originally posted by: Matt L
When the system quits, press and hold the REST key on the pushbutton unit for >5 seconds, until the display changes to read "1" on the left side and a sensor value on the right. Press the right AUTO key to rotate through the list and write down the values.



Next, turn the engine off and turn the key to position 2 (don't start the engine).

Set the temperatures, 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 are displayed. Record each DTC as it is displayed.

To erase: Only possible after DCT's are red out. Simultaneously press both AUTO > 2 secs. The display will read "d" and "FF" on the two sides.



The information derived from these tests will probably tell what is wrong. It's likely the evaporator temperature sensor, but the above procedure will show for sure.

Ok here is what I got from the first test:
1 22
43 152
42 72
41 34
40 71
24 13.5
23 00
22 00
21 06
20 0.0
12 4.1
11 3.1
10 3.2
9 10
8 27
7 05
6 83
5 62
4 21
3 21
2 24
1 23

2nd test:
E61 234
E61 459
E FF
E

What do you think?

-------------------------
1998 Mercedes e320

Matt L on Sun June 15, 2008 9:46 PM User is offline

Those 6's in the trouble codes are really b's.

B1234 is for the sun sensor. You can ignore this one.
B1459 is "Series interface (K2) connection to instrument cluster (A1)". I'm not sure that this is especially relevant, although there may be a problem. The instrument cluster supplies vehicle speed, engine speed and coolant temperature.

For the current-sensor readings, some of the modules report in C and some in F. Since you're even asking about AC, I have to assume that yours reads in C and it is about 22C ambient (reading #1). Reading 3 and 4 are the left and right heater core temperature sensors, and 5 is the evaporator temperature sensor. Reading #5 is clearly wrong. Replace the evaporator temperature sending unit. It is cheap and easy to change.

djmacc on Mon June 16, 2008 11:14 AM User is offline

Quote
Originally posted by: Matt L
Those 6's in the trouble codes are really b's.



B1234 is for the sun sensor. You can ignore this one.

B1459 is "Series interface (K2) connection to instrument cluster (A1)". I'm not sure that this is especially relevant, although there may be a problem. The instrument cluster supplies vehicle speed, engine speed and coolant temperature.



For the current-sensor readings, some of the modules report in C and some in F. Since you're even asking about AC, I have to assume that yours reads in C and it is about 22C ambient (reading #1). Reading 3 and 4 are the left and right heater core temperature sensors, and 5 is the evaporator temperature sensor. Reading #5 is clearly wrong. Replace the evaporator temperature sending unit. It is cheap and easy to change.

So far I have found an evaporator anti ice sensor. Is that the same as temp sensor? Some sources say there are 2 possible parts?

-------------------------
1998 Mercedes e320

Matt L on Mon June 16, 2008 2:41 PM User is offline

The sensor does shut the compressor down if the evaporator temperature gets too low, so this does sound like the part. The compressor also shuts down if there is an improbable reading at this sensor, which describes your situation.

Are the two possible parts from two different manufacturers, or for different chassis number series? You might consider calling a local dealer for the part, to ensure that you really get the OEM sensor.

djmacc on Mon June 16, 2008 6:20 PM User is offline

Quote
Originally posted by: Matt L
The sensor does shut the compressor down if the evaporator temperature gets too low, so this does sound like the part. The compressor also shuts down if there is an improbable reading at this sensor, which describes your situation.



Are the two possible parts from two different manufacturers, or for different chassis number series? You might consider calling a local dealer for the part, to ensure that you really get the OEM sensor.

Thanks

-------------------------
1998 Mercedes e320

djmacc on Tue June 17, 2008 10:15 PM User is offline

Quote
Originally posted by: Matt L
The sensor does shut the compressor down if the evaporator temperature gets too low, so this does sound like the part. The compressor also shuts down if there is an improbable reading at this sensor, which describes your situation.



Are the two possible parts from two different manufacturers, or for different chassis number series? You might consider calling a local dealer for the part, to ensure that you really get the OEM sensor.

YOU'RE THE MAN! It took a little while to figure out where they hid the little sucker under the dash but I got in installed and it works great. Thanks alot!

-------------------------
1998 Mercedes e320

Matt L on Tue June 17, 2008 10:36 PM User is offline

I'm glad to have been able to help.

Enjoy your AC. The automatic climate control in the W210 is pretty good when everything is working right.

nedim on Fri August 22, 2008 9:43 AM User is offline

Hey guys, I am having similar problem. Where is the antiice sensore located and how do I replace it?
Thank you

Matt L on Fri August 22, 2008 1:27 PM User is offline

I've never had to change mine, but I believe that it is located on the left side of the evaporator case under the dash. You probably have to remove the bottom and side panels to get to it. Removal or dismantling of the evaporator case is not required.

nedim on Sat August 23, 2008 12:48 PM User is offline

what did you have to do to your? what was a problem?

Matt L on Sat August 23, 2008 1:17 PM User is offline

My car was suffering from a plugged dryer, which caused a very warm left-side vent and seemingly proper pressures with only 15oz of refrigerant in the system.

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