BenzWorld Junior Member
Date registered: Jul 2016
Vehicle: 2005 R230 SL500
Location: Santa Fe, New Mexico
Mentioned: 0 Post(s)
Quoted: 7 Post(s)
AC Problem: DTC B1057, fault in CAN communication with RCP
2005 SL500, R230 has 129000 miles. Have owned it for 4 years, never any AC issues before. Car was in storage all winter.
Brought out 2 months ago and the Air Conditioning is only blowing hot air. AC button has red light on. Push it and it flashes twice and then stays on.
With the warm weather I started troubleshooting.
Error code B1057, fault in CAN communication with control unit RCP (Roof Control Panel). I have cleared the error twice, returns immediately but the red light is off on the AC button.
With the engine idling and the AC on,
The diagnosis shows:
N22b1 - in car sensor is at 40 degree C
N706 - in car sensor is at -128 degree C
B14 - Ambient sensor is at 46 degree C
B10/6 - Evaperator sensor is at 39 degree C
B11/4 - coolant sensor is at 97 degree C
B12 Refrigeration pressure measuring 10 bar with AC on and 8 barr with AC off.
A9 Refrigeration Compressor 70% with AC on.
I am not sure what to look for with the error B1057?
The in car sensor N706 reading -128 degree C, I think is wrong. Where can I find this sensor to replace it?
Is the refrigeration pressure of 10 bar satisfactory?
I am using the i980 carsoft reader. Thank you, Patrick