AC suddenly stopped working, code 419
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1998 E300 Turbodiesel
AC suddenly stopped working, code 419
Suddenly a few days ago the air conditioning stopped working on my 1998 E300 diesel. It turns out the compressor is not switching on. There is plenty of pressure in the system (about 75 psi rest pressure), so the problem is not loss of refrigerant.
Running diagnostics brings up error codes 233 and 419. I've seen code 233 on this car before, it's the refrigerant temperature sensor, but the system worked OK despite this. The code 419 is new, I looked it up as "compressor not switching on." If I'm reading this correctly this is saying that the ACC system is attempting to turn on the compressor and it is not responding. (ACC diags show pressure at 5 bar, which corresponds to the gauge set reading, so the pressure sensor is working.)
This was verified visually, the compressor clutch is not switching on. I was unable to find a fuse for this, though there must be some kind of protection for this circuit somewhere. The compressor itself turns easily and smoothly by hand, so I don't think there is a fault in the compressor beyond the possibility of a bad clutch coil.
And that's where things sit right now, I'm not sure where to go next for troubleshooting purposes. Is there a relay or circuit breaker somewhere that might be faulty? The compressor and clutch wiring cannot be accessed without a fair amount of disassembly. What else can be checked before starting to take things apart? (Frankly at this point we are near the end of air conditioning season, if this is going to take a lot of work it will probably be left until spring...)
Running diagnostics brings up error codes 233 and 419. I've seen code 233 on this car before, it's the refrigerant temperature sensor, but the system worked OK despite this. The code 419 is new, I looked it up as "compressor not switching on." If I'm reading this correctly this is saying that the ACC system is attempting to turn on the compressor and it is not responding. (ACC diags show pressure at 5 bar, which corresponds to the gauge set reading, so the pressure sensor is working.)
This was verified visually, the compressor clutch is not switching on. I was unable to find a fuse for this, though there must be some kind of protection for this circuit somewhere. The compressor itself turns easily and smoothly by hand, so I don't think there is a fault in the compressor beyond the possibility of a bad clutch coil.
And that's where things sit right now, I'm not sure where to go next for troubleshooting purposes. Is there a relay or circuit breaker somewhere that might be faulty? The compressor and clutch wiring cannot be accessed without a fair amount of disassembly. What else can be checked before starting to take things apart? (Frankly at this point we are near the end of air conditioning season, if this is going to take a lot of work it will probably be left until spring...)
Last edited by wbuckman; Aug 26, 2013 at 01:19 PM.
