W210 AC failed again
 

Well the A/C failed yesterday.

Has been working great for 4 or 5 months now with many trips to town and a few trips to other cities in the area running hard all day and night this Texas summer until yesterday.

Car has been sitting, not being used, for a couple of weeks. Yesterday I drove to town for an hour and everything was normal; stopped at the car wash and blasted the car with high pressure water for ten minuets with the car running and when I got back in the A/C control unit was lit up and flashing like a Christmas tree with hot air blowing and an agonizing horn sound coming from the dash.
The A/C would not respond at all. Lowered the windows and drove home.

Upon arriving home and let the car cool off under a tree for awhile and upon restarting the car the control unit is functioning but no cold air and the compressor is not running. codes are:
Eb1230
1232
1235
1422

1 58
2 67
3 E
4 E
5 E
6 220
7 E
8 80
9 27
10 E
11 E
12 4.0
20 3.2
21 76
22 31
23 32
24 15.4 flicker to 0 from time to time
40 164
41 32
42 40
43 152

Today reset the control unit this morning and this afternoon. The unit seems to be functioning properly and the readings are:

am
Eb1230
1459
1230
1232
1422

1 58
2 67
3 58
4 58
5 E
6 220
7 E
8 78
9 27
10 2.1-2.5
11 E
12 3.4
20 3.2 scramble 9.1
21 76
22 31
23 32
24 14.6
40 154
41 32
42 40
43 152

pm
1 58
2 67
3 58
4 58
5 E
6 220
7 E
8 82
9 27
10 6.0
11 E
12 3.9
20 3.2
21 42-76
22 31
23 32
24 14.8
40 164
41 32
42 40
43 152

Need help with the A/C puzzle again.

numbers from today
 

Need to start making headway on the E300. I have every vehicle in need of repair and so I am overwhelmed.
These are the numbers from today. It is 82 degrees outside right now.
Is it possible that the car wash caused this problem?

Eb1232
1235
1419
1422
1424
1230

1 57
2 67
3 57
4 57
5 E
6 120
7 E
8 80
9 27
10 60
11 E
12 42
20 9.1
21 76
22 31
23 32
24 10.2-11.2 fluctuates
40 164
41 32
42 40
43 152

total rebuild lately
 

5 months ago the car got new everything but the compressor that was new two years ago.
new: evaporator and heater core, expansion valve, condenser, drier, control unit

When I got it all back together (dashboard etc) the control unit failed due to a pinched wire behind the washer water tank. The power line to the compressor had a small cut in the insulation and shorted so I just wrapped in electoral tape and all was good until now.

[QUOTE=BiodieselMB;3752249]Need to start making headway on the E300. I have every vehicle in need of repair and so I am overwhelmed.
These are the numbers from today. It is 82 degrees outside right now.
Is it possible that the car wash caused this problem?

The fact that everything was o.k. prior to the car wash I would have to suspect that the high pressure water has something to do with your current problem. Something may have been shorted out which caused your ac control unit to lite up like a Christmas tree. I would check any connections to the compressor and the repair you made to that wire to insure that there is no water intrusion. Good luck

I'm sitting here wondering about the E on the 5 and 7. Those are (IIRC) evap temp and pressure? If they ain't there then don't expect it to work. I'd start with trying to make them provide a reading.

How to test the K1
 

Had to do research on the IIRC codes. funny.

Okay working on the assumption that it was caused by the car wash, isn't it curious that the K1 unit is located directly under the air intake on the hood?
I have removed the K1 in the hope of seeing anything curious but everything seems normal but I need to learn a test procedure on the AC brain.

well i see now that the box labeled K1 is the throttle control unit and not the K1 that I was looking for. Sure would be great if I had bought the service manuals when they were available.

not a popular subject Climate Control
 

Troubleshooting Instructions
Entering Diagnostic Trouble Code (DTC) Display Mode

1) Turn ignition on. Press the down arrow push button until “LO” is shown on the right and "HI" on the left in A/C-heater control panel temperature display window.
2) Within 20 seconds, simultaneously press REST and EC push buttons for more than 2 seconds. The Light Emitting Diode (LED) in the recirculated air push button will blink and the display window will show “di R”.3) Press AUTO push button repeatedly, recording each DTC,until all DTCs are displayed. Permanent malfunctions are displayed first. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION tables.
4) If no permanent malfunctions are stored, the display window shows “En d”. Press AUTO push button again. Intermittent DTCs will be displayed. Intermittent malfunctions are recognizable by the degree (°) symbol displayed along with the DTC (example: “04 °”).
5) If no intermittent malfunctions are stored, the display window shows “En° d”. Proceed to ERASING DIAGNOSTIC TROUBLE CODES.

Climate control as a diagnostic tool

READING SENSOR VALUES

1) Turn ignition on. Simultaneously press down and up arrow push buttons until the pre-selected temperature setting of “72 °F” is displayed. Press the AUTO push button.
2) Press REST push button for more than 6 seconds. The display window will alternately show “01” and an in-car temperature of “72 °F”, or “LO” if there is an open circuit, or “HI” if there is a short circuit.
3) By pressing the windshield air distribution push button, the next ascending test step is displayed. By pressing the footwell air distribution push button, the next descending test step is displayed. See SENSOR VALUE DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION table. Press REST push button to exit reading sensor values mode.

01 = In-car temp sensor
02 = outside temp sensor
03 = left heat exchanger (heater core) temp sensor
04 = right heat exchanger sensor
05 = evaporator sensor
06 = coolant temp
07 = refrig. pressure in bar
08 = refrig temp sensor (23*9 = 23.9deg C)
09 = nothing
10 = Blower control voltage (great for evaluating blower controller problems)
11 = emissions sensor (B31) e.g. 3.1 = 31.v
12 = sun sensor 4.2 = 4.2v
20 = aux fan control 6.1 = 6.1ma (max 10ma)
21 = engine speed
22 = vehicle speed
23 = Circuit 58d e.g. 99 = 99% of battery voltage
24 = BATTERY VOLTAGE e.g. 12.5 = 12.5v
30 = left rear air conditioning heat exchanger temp sensor (not all vehicles; obviously)
31 = right side
32 = rear evap temp sensor
33 = blower control voltage rear 0.8(MIN) – 6.0(MAX)
34 = left rear temp selector
35 = right side
38 = software status e.g. 37 rear air conditioning
38 = hardware status e.g. 37 , rear air conditioning
40 = control module version software status (?)
41 = control module version menu hardware status
42 = control module variant code 1st number
43 = variant code second number.

DCT table:

B1226 - In-car temperature sensor (B10/4)
B1227 - Outside temperature indicator temperature sensor (B14)
B1228 - Heater core temperature (B10/1)
B1229 - Heater core temperature (B10/1)
B1230 - Evaporator temperature sensor (B10/6)
B1231 - ECT sensor (B11/4)
B1232 - Refrigerant pressure sensor (B12)
B1233 - Refrigerant temperature sensor (B12/1)
B1234 - Sun sensor (B32)
B1235 - Emissions sensor (B31)
B1241 - Refrigerant fill
B1416 - Coolant circulation pump (M13)
B1417 - Duovalve (Y21y1), left
B1418 - Duovalve (Y21y2), right
B1419 - Electromagnetic clutch (A9k1)
B1420 - Idle speed increase
B1421 - Pulse module (N65)
B1422 - Series interface (K1) connection to instrument cluster (A1)
B1423 - Switchover valve block (Y11)
B1424 - Activated charcoal filter actuator (A32m2) open
B1425 - Activated charcoal filter actuator (A32m2) closed
B1432 - Non-USA DTC
B1459 - Series interface (K2) connection to instrument cluster (A1)
B1462 - Wide open throttle (WOT) position signal: diesel engines

line 24
 

Is it normal for the battery voltage (line 24) to fluctuate?

Problem solved
 

Problem solved.

It was dissolving insulation on the wiring harness of the emissions sensor.
11 = emissions sensor (B31) e.g. 3.1 = 31.v]Attachment 144579

Attachment 144580

Good catch, where is it located? Hard to tell by the pic.

It's under the air intake passenger side under the trim piece.

Dang I better check mine this weekend...

when I performed the AC rebuild, the location of that harness and connection seemed strange that it was outside and under the box. If it was located inside the box it may not have shorted against the plastic box.

If you find that yours is located in the box please let us know.

Today I will try to disassemble the harness and wrap the wires, as the price of the part is hundreds of dollars.

please tell me what you think about rebuilding this part.
 

part number 210 830 01 72
Attachment 144599
Please tell me what you think about rebuilding the wires on this part.
Attachment 144600

Or bypassing the sensor?

Mercedes calls it; Gaseous Pollution Sensor . $545 retail .

I believe this is the sensor that is mentioned in the W210 brochures, it automatically activates the carbon filters in the cabin when it senses a very concentrated exhaust environment (e.g. following a diesel city bus)

I love the feature but would not mind eliminating it if the button on the dash would still activate the carbon filters.

dam

I believe the ACC system gets its air intake temp signal from that sensor as well. When it doesn't work you get constant "67" for the #2 data point. My car does this even though the outside temp display in the instrument cluster works fine (sensor in bumper).

I always wondered where the IAT sensor was for the climate control. Definitely not the same signal as the bumper sensor. Thanks for solving that mystery!

I would definitely be rebuilding that cable if it was me.

I did this trick for saving my seat occupancy sensor on the passenger side, its wires had failed like that.

First make note of which wire color is which on the connector.
Cut the connector wires about 5-6 inches away from the connector. Stagger the cuts about a half inch. Pull off all the remaining bits of insulation. Neatly re-twist the wires (try to follow the original factory direction of twisting).
Find the thinnest heat shrink that will cover the exposed wires. Slide this heat shrink down all the way until the end is within the connector body. Leave about an inch exposed at the other end. Shrink this tubing with a heat gun on all 4 wires. Now you've re-insulated the wires going into the connector, without having to re-build the connector.
If you have access to some decent selection of cable find a suitable 4-conductor cable that will fit the grommet on the device. Lead the cable into the device and solder the wires to the circuit board. Otherwise find 4 colored pieces of hook up wire and either heat shrink tube all 4 together or wrap with electrical tape.
Now when you go to make your splices you can individually heat shrink these with a little larger piece of heat shrink to cover your solder joint, then slide this over the skinny heat shrink that replaced the wire insulation going into the connector. Finally cover the whole splice area with a larger piece of heat shrink.

Of course you have to plan ahead and have all the pieces staged up on the cable before you solder the joint. And you have to watch your heat on the joints, lest you start to shrink up the heat shrink prematurely while it's waiting to be slid over the joint.

I would also look at the wire you found damaged earlier by the wash tank and repair that with solder and heat shrink as well.

Heat gun at HFT $15
Assortment of heat shrink tubes < $10
Cheap soldering iron and solder $15

Superior repair = priceless

Junk Yard sensor
 

Fifty dollars plus 1/2 day shipping by me and its here for the weekend of cold cruising.
Attachment 144611

jay_bob thank you
 

Jay Bob thank you for your reply. Your explanation is perfect and what I would have done and saved $10 and a day of San Antonio traffic but got lucky at the junk yard.

I think that all of us should do what you recommend because of the cost of the part.

Not sure the mystery is quite solved! We installed a new windshield in our E300 over the weekend. During prep I noticed a wire and thicker tube running from the body into the air intake assembly that's mounted to the hood, running up by the LH hood's hinge. The tubing is obviously for the washer fluid. The wire could be a lead to/from a temp sensor mounted in there. I should take a look. Either way I'm confident the ACC system gets its intake temp signal from a sensor other than the one mounted in the bumper.

Also, I've repaired wiring in the headlight assemblies doing what you describe Jay Bob, using heat shrink to make fresh insulation for existing wires. Worked great!

your correct gmog220d
 

AC even more broken now

As I was installing the new pollution gizmo the insulation on the wire started to fray so I encapsulated it all with four coats of liquid electrical tape. The wiring omed out good.

Attachment 144641

Started the car and the controller on the dash is malfunctioning and no AC

Now I am looking forward to pulling the car apart again.

I have repaired wires w/ failed insulation by wrapping each individual wire w/ self-fusing silicone electrical tape (any hardware store). That was on my 2002 T&C where the factory ran the fuel injection harness too close to an exhaust pipe. I read that some later M-B (yours?) were made w/ bio-degradable wire insulation which is degrading prematurely.

ohmed
very funny

It is a 1996 E300D. This is the first sign of the problem that I have heard of for so long.

I remember hearing that the biodegradable insulation started in 1996 and I have alway hoped that the car was before the vin break.

Found the problem..
 

and it was.. user error installing the Multifunction Control Unit N10-1 labeled K1.
Some years ago the plastic tab on the connector for the transmission control module (2) broke off so I have been using a wrench to pull up on the the connector to remove it.
So I got lazy and the connection started to just open with the metal lever (2)
and it would go back together and look good so it worked for a few months and the AC would fail.
Finally two days ago I took everything apart, searching of the problem, and when it was all back together I wiggled all of the connections and the connection popped totally apart. I installed it correctly (it was obviously tight) went to the junk yard and was lucky to find another push button control unit for $150 and everything is back to normal.
Attachment 145703

Multifunction control module (N10-1) and transmission control module (TCM), 5-speed automatic N15/1 or transmission control module (ETC,
N15/3)

1 Pull slide catch for connector for windshield wiper and blower motor control module box (2) up and disconnect connector from multifunction
control module (N10-1).

2 Open connector (2) and separate coding section for connecting blower motor and control module box from connector.

3 Pivot locking tab (1) up and pivot connector for multifunction control module (N10-1) to side and remove control module from control module
box guides. NOTE: The connector for the multifunction control module (N10-1) is mounted on the bottom of the control module box so that it can pivot
Pivot connector to side so that control module can be pulled out upward without resistance.

4 Disconnect connectors from 5-speed automatic transmission control module (ETC, N15/1) or transmission control module (ETC, N15/3) and
remove control module.

Thank you to all for your inspiration through this AC repair, I have learned a lot and now the system is "new" again and the seat moves as it should and the blinkers blink again and the windshield wiper wipes and the aux fan works consistently and I will never again be sloppy connecting the brains.