# 98 740iL CEL with fault code 8B



## cesarpeji (May 30, 2007)

I had a check engine with fault code of 8B + electric thermostat control final stage!!

What is it that I need to replace? Anyone has had the same problem before, Need help

Cesar
[email protected]

Thanks.


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## mini1day (Dec 3, 2007)

I know its been almost a year, what did finally result on that fault, cause I have the same one 
thanks
Paulo


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## Black 840Ci (Feb 8, 2008)

Replace your thermostat housing!!!


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## nuttybgc (Mar 14, 2008)

What are the symptoms for the 8b peak code "Electric thermostat control final stage" to come up???


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## Beemaboy (Jun 1, 2006)

nuttybgc said:


> What are the symptoms for the 8b peak code "Electric thermostat control final stage" to come up???


I would guess that the error occurs when the computer can no longer control the electronic thermostat within its tolerances. Either the heating element or the wax breaks down and will not function properly...


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## f1racer8292 (Aug 2, 2009)

we had the same problem with the same exact car. What we did was we replaced the oxygen sensor, and it turned off!


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## nuttybgc (Mar 14, 2008)

f1racer8292 said:


> we had the same problem with the same exact car. What we did was we replaced the oxygen sensor, and it turned off!


Where is that sensor located?


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