Thermostat CEL and incorrect temp readings

icekxd · 07-01-2021, 05:02 AM

Hi,

I recently had a CEL pop up. Scanned the car and two errors came up:

1D2008 Map controlled thermostat stuck open
10AA30 Coolant temperature sensor: group error

The only symptoms are CEL, no oil temperature reading on the digital gauge and when accessing temperatures inside hidden menu coolant is at -128 degrees Celsius and oil temp at +207 degrees Celsius. Obviously both values are impossible. Doing a live parameter check with Carly the oil temp is normal and I'm unable to check coolant temperatures (no reading). Also, the front fan is running excessively fast.

Once reset, all symptoms disappear. I do have warm air from hvac and A/C works as it should. The ambient temp outside daily is 30-35 degrees in shade. I imagine it is twice that in the sun. The engine does not take longer to warm up that it usually would. The CEL comes back irregularly, but when it does the second error (10AA30) does not reappear.

Perhaps somebody has some information if this is the thermostat asking to be replaced or whether a sensor has gone bad. I have thought that there might be some wiring issues as well, but resetting the errors would make them reappear immediately if it were the case.

Car is a 2015 N55.

Thanks

coltoncox72 · 08-28-2023, 10:52 AM

Hey, I am having the same problem with my 335i, would you mind sharing what you did to fix this?

07-01-2021, 05:02 AM	#1
icekxd New Member 3 Rep 20 Posts Drives: BMW M235i Join Date: Oct 2020 Location: EU iTrader: (0)	Thermostat CEL and incorrect temp readings Hi, I recently had a CEL pop up. Scanned the car and two errors came up: 1D2008 Map controlled thermostat stuck open 10AA30 Coolant temperature sensor: group error The only symptoms are CEL, no oil temperature reading on the digital gauge and when accessing temperatures inside hidden menu coolant is at -128 degrees Celsius and oil temp at +207 degrees Celsius. Obviously both values are impossible. Doing a live parameter check with Carly the oil temp is normal and I'm unable to check coolant temperatures (no reading). Also, the front fan is running excessively fast. Once reset, all symptoms disappear. I do have warm air from hvac and A/C works as it should. The ambient temp outside daily is 30-35 degrees in shade. I imagine it is twice that in the sun. The engine does not take longer to warm up that it usually would. The CEL comes back irregularly, but when it does the second error (10AA30) does not reappear. Perhaps somebody has some information if this is the thermostat asking to be replaced or whether a sensor has gone bad. I have thought that there might be some wiring issues as well, but resetting the errors would make them reappear immediately if it were the case. Car is a 2015 N55. Thanks Last edited by icekxd; 07-01-2021 at 05:09 AM..
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08-28-2023, 10:52 AM	#2
coltoncox72 Registered 0 Rep 1 Posts Drives: BMW 335i Join Date: Aug 2023 Location: North Carolina iTrader: (0)	Same Issue Hey, I am having the same problem with my 335i, would you mind sharing what you did to fix this?
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