Rod, Your vehicle has 4 x O2 sensors (1 x Pre Cat Bank 1-3, 1 x Post Cat Bank 1-3, 1 x Pre Cat Bank 4-6 and 1 x Post Cat Bank 4 -6). According to the BMW Electrical Trouble shooting Manual for your car (
http://www.wedophones.com/Manuals/BM...g%20Manual.pdf ) Based on my reading,
the wires connecting each sensor to the DME have the same colour code:- Red with White Stripe (Battery + from Terminal 87 of the Engine control module relay), Brown (which is the heater Ground wire), Yellow (Which is the sensor signal) and Black (which is the sensor ground). The pre cat sensor for Bank 1 -3 is designated component B62101 and the Brown, Yellow and Black wires from the sensor connect to terminals 25, 75 and 67 of your DME. The same colour wires from the post cat O2 sensor for cylinder Bank 1-3 (Component B62102) connect to terminals 79, 77 and 71 of your DME. Pre (Component B62201) and post cat (Component B62202) connections for the O2 sensors which relate to Cylinder Bank 4-6 are to terminals 55,76,70 and 61,78,72 respectively. As Dark Horse says, the heater is built into the sensor, so if continuity of the wiring harness checks out, replacement of a bad sensor is the only option. Hex code 19 (Dec code 25) is applicable to the M52 engined vehicles, so you ARE reading the correct table from your Peake Tool handbook.
