[s-cars] A potential diagnostic for the knock sensor(s)

[Dave Forgie]

If there is an issue with the knock sensors, the CEL will throw a 2142
blink code for the front cylinders (1 and 2) knock sensor No. 1 (device
G61 on the wiring diagrams); if it is knock sensor No.2 (G66 for the
rear cylinders 3, 4 and 5), it will throw 2144.  The connectors to the
ECU for G61 and G66 are both three pin AMP plugs, on the firewall
connector rack (under the plastic cover).  I am thinking that if a 2144
code showed up, i.e. the rear knock sensor was bad, one way to confirm
this would be to swap the G61 and G66 connectors and restart the car.
This should fool the ECU and if G66 was really bad, the ECU should then
throw a 2142 code (because it thnks there is a bad G61 knock sensor). If
the code still comes up 2144, it could be the wiring from the G66
connector (at the rack) to the ECU.

I don't have a bad knock sensor to try this out on so I was wondering if
somebody has tried this trick (like swapping the POS connectors to see
if the "bad" cylinder jumps 3 positions) for the knock sensors.

Dave F.