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Resident Curmudgeon
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23,358 Posts
You sure it's the O2 sensor? Check the O2 heater fuse and the wiring/connector ....

But can't help w your specific question

GL
 

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Resident Curmudgeon
Joined
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23,358 Posts
No idea

But I did a google...look at this schematic:



See that 30A fuse at the top? If that fuse is blown, OR if any connection to the heaters in each O2 sensor is open, the DME will immediately see 'no current draw on the O2 sensor HEATER' and trip a code. This is immediate upon starting the car- whereas other O2 sensor codes, due to aging sensors, usually will only trip once the car has warmed up and it tries to go into closed loop control.

Having said this, that diagram is NOT AN E70. I dont have one handy. If one fuse powers two sensors you shoudl (I think) see both codes. This would lean away from a fuse and more towards a connector or in fact an open coil in the heater within the sensor itself....
 
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