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.

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

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

__________________
96 E300d

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.

__________________
Jim

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.

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

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

Problem solved.

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

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

__________________
Jim

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

Dang I better check mine this weekend...

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

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.

part number 210 830 01 72

Please tell me what you think about rebuilding the wires on this part.

Or bypassing the sensor?

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