G50: Knock Sensor Test Revisited

[sdkhalsa]

Hello Q45tech and Friends,

To continue the saga a bit further, after testing the resistance of my knock sensors, I discovered that one had a normal reading but that the other had an open(completely shot). I grounded the lead going to bad sensor(all connections in place) with a 560 K Ohm pot. The code "34" vanished upon reset with my consult. Performance was excellent, with the previously reported flat spot in acceleration gone. The retarding of spark that I had previously seen on the consult screen was also gone. Unusually, when I grounded out the good sensor(same set-up as above) I also had the excellent results, contrary to expectations. My original plan was to tie both the leads into the one good sensor, thus switching from stereo knock microphone to monoral. This did not help matters at all, and code "34" came up with the old poor performance. I suppose that this might have worked if I rebalanced the resistance value. In doing this I was trying to follow-up on Q45tech's mention of the need to maintain a certain level of sensor noise to avoid throwing a code. Any thoughts?

[Q45tech]

Winter is never a good time to think you have a KS problem solved.

Summer heat and funky gasoline can leave you miserable with a jeeped up KS system.

The KS ecu has 2 identical but separate amplifer chains that are combined after the frequency shaping.

http://focus.ti.com/lit/ds/symlink/tpic8101.pdf

http://www.intersil.com/data/an/an9770.pdf