Functional description, see BMW Service Technology:
TIS -> Document -> SI Technology -> Enter SBT Number
SBT number:
The S85 had an exhaust gas temperature sensor for each cylinder bank up to 09/2006. The exhaust gas temperature sensors were located in the exhaust line after the engine-proximate catalytic converters and were used by the DME for catalytic converter protection.
Note:
As of 03/2006, the signals of the exhaust gas temperature sensors will no longer be used in the DME! However, the exhaust gas temperature sensors were fitted up to 09/2006. The signals are replaced by calculated exhaust-gas temperatures. The exhaust gas temperature sensors will no longer be diagnosed in the DME, either.