B1020 error code for air conditioning.
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Junior Member
Joined: Dec 2017
Posts: 23
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From: NYC - South Florida
GL-450, CLK-350
B1020 error code for air conditioning.
I have searched a few forums with no help and I'm hoping someone here can shed some light on an issue I have. 2006 CLK-350 cabriolet.
My CLK sits for a month or two at a time and over the 16 years I've owned it I've only driven 71K miles and usually up and down the east coast. Never had an issue with this convertible until now.
Started the car and no a/c, it blew outside temperature air with no cooling. Checked the compressor and it is engaged so I went to MB dealer and they ran a diagnosis. They suggested a recharge, leak test and replenishment of compressor oil. Upon checking the existing levels they found that they where actually OK and within tolerance. Upon running diagnosis these error codes where returned, B1020 - B10/6 (Evaporator temperature sensor), current and B1115 - Fault in CAN communication with the control module 'Automatic A/C (AAC/KLA), stored.
They suggested replacing the evaporator temperature sensor at a cost of over $500 with the MB part costing $122. I passed but had them evacuate and recharge the a/c.
Through FCP Euro I replaced the sensor myself and went to a friend who has and AUTEL diagnosis computer. We ran diagnosis to clear the code and restarted the car just to find the both codes returning.
I find it hard to believe the sensor was bad out of the box so I bought another one and performed a clear and restarted the car with the same results. The fan works, the compressor is running but still no cold air from the vents.
Another private shop stated that the heat could be running and the control valve might be stuck open. We checked that and it isn't the issue, we even went so far as to clamp the heater hose to stop coolant from entering the heater core.
Needless to say this is a bit aggravating after spending over $700 at the dealer with no retort. They are claiming that my whole control system might be shot as their mechanic stated the temperature sensor is reading vent air at 225 degrees. ??
Makes no sense but I'm hoping someone here might be familiar with this issue or has seen it in the past.
My CLK sits for a month or two at a time and over the 16 years I've owned it I've only driven 71K miles and usually up and down the east coast. Never had an issue with this convertible until now.
Started the car and no a/c, it blew outside temperature air with no cooling. Checked the compressor and it is engaged so I went to MB dealer and they ran a diagnosis. They suggested a recharge, leak test and replenishment of compressor oil. Upon checking the existing levels they found that they where actually OK and within tolerance. Upon running diagnosis these error codes where returned, B1020 - B10/6 (Evaporator temperature sensor), current and B1115 - Fault in CAN communication with the control module 'Automatic A/C (AAC/KLA), stored.
They suggested replacing the evaporator temperature sensor at a cost of over $500 with the MB part costing $122. I passed but had them evacuate and recharge the a/c.
Through FCP Euro I replaced the sensor myself and went to a friend who has and AUTEL diagnosis computer. We ran diagnosis to clear the code and restarted the car just to find the both codes returning.
I find it hard to believe the sensor was bad out of the box so I bought another one and performed a clear and restarted the car with the same results. The fan works, the compressor is running but still no cold air from the vents.
Another private shop stated that the heat could be running and the control valve might be stuck open. We checked that and it isn't the issue, we even went so far as to clamp the heater hose to stop coolant from entering the heater core.
Needless to say this is a bit aggravating after spending over $700 at the dealer with no retort. They are claiming that my whole control system might be shot as their mechanic stated the temperature sensor is reading vent air at 225 degrees. ??
Makes no sense but I'm hoping someone here might be familiar with this issue or has seen it in the past.
