My 2002 CLK 430 Coupe has been sitting in my garage for 3 months and started weekly & running for 15 minute. I went for a drive today and noticed my Air Conditioning doesn't blow cold. I think it turns itself on and no cold air is coming out. I ran the A/C diagnostic test via sdconnect c4+dell d630 and came back with 2 error codes and the following numbers.
AIR CONDITIONING TROUBLE CODES: (BY Star Diagnosis SD C4)
(38) 01 The in-car temperature sensor.
(20) 02 The bumper temperature sensor. (im pretty sure this sensor is faulty)
(38) 03 The temperature of the left side heater core.
(38) 04 The temperature of the right side heater core.
(35) 05 The temperature at the evaporator sensor.
(83) 06 The engine coolant temperature.
(10) 07 The barometric pressure of the Freon.
(44) 08 The Freon temperature.
It was hot yesterday. All values in celsius. It was probably 35 celcius. I drove the car for 15 minutes and parked in my cool underground parking stall to perform the test. I have a hissing sounds cycling on and off from behind my center vents (clue?). As you can see from the value of temp sensor 2 that the sensor is busted. No way it was 20 degrees by the bumper. Although i was under the impression this sensor had been broken for a while even while the A/C worked before.
diagnosis SDconnect C4 (to read&clear codes)
Ideal solutions for bad A/C:
1. The trouble codes mean that the coolant circulation pump is failed.
2. I cleared the codes today and indeed the coolant circulation pump code is gone!
3. Try a charge.
Success!!! Turns out the little guy just needed a good freon recharge and now she blows cold cold cold. Turns out there is already dye in my system which makes me suspect there is a tiny leak somewhere. My A/C Tech friend who charged my system mentioned that the previous owner was likely trying to find the leak and knew of the problem. I'm happy to say my highway jaunt down to Calgary for the weekend will be cool...calm and collected. Cheers!