I swapped from a 7747 to a 7427 fairly recently.

In the beginning I just disabled the knock retard and corresponding error code 43, this was so I could focus on just getting the PCM to idle and run decently, which I have now done.

I installed Standard Motor Products Knock Sensor P/N# KS6: late style TBI knock sensor, I cut the 4 wire plug going to the ESC module, I connected the BLUE wire to the BROWN wire from the ESC plug, I pinned the knock sensor wire to pin B15.

Without even leaving the driveway, the knock sensor circuit failure popped up, (CODE 43).

What do I need to change with the wiring in order to get the knock sensor to work properly? And what about those two other wires from the old ESC plug?

 

You want to jumper E & C together at the ESC module plug. In the two wiring diagrams I looked at brown is ground.

Also, check the resistance of the knock sensor, can do it right at the ESC module connector (between pins E & D). Should be 3.9K ohms. A 100K ohm sensor isn't the correct one.

Pin D at the ESC module connector is engine block ground.

RBob.

 

Thanks for the clarification RBob. All the information on the internet that I've found says "connect blue to brown @ ESC" No surprise that you can't go just by the color alone!

I started thinking about this last night: Hooking it up with "blue to brown" is like having two grounds (-), but no (+)! No wonder it didn't work, thats not a complete circuit!

I would have easily realized which wire went where in the first place, but 24 years of being under the hood has started to fade the color on the insulation of some wires, so I didn't realize right away that one of the wires from the old ESC plug IS IN FACT the same YELL/BLK wire that goes into the cab and ends up at the PCM plug. I tested for continuity and yup! that's the wire!

So I changed the wires around, burned a chip and test drove, the knock sensor appears to be working great!

Thanks!

 

Yes, so true. This is why I like using the terminal designations, even though from time to time they too can be hard to see.

Glad to hear you got'r going.

RBob.