Mechanics

CODE 43

1994 GMC Sierra • 265,960 miles

What is theit common problem for Code 43 on a 94 gmc sierra half ton 4wd 350?
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Kristinvanvalkenburg
September 16, 2012.



What is the** oops

It is a knock sensor issue. It could be the wiring, connector or the sensor itself.

If you have a scan tool, monitor the timing and then tap on the top of the motor with a hammer and it should retard 4 degrees.

Roy

ASEMaster6371
Sep 16, 2012.
Knock sensor is new, would the diagnostic test read a bad knock sensor? Like show up as knock sensor?

Its already retarding at 4degrees too

A code number never identifies a bad part, just a failed system.

If the timing is 4 retarded, disconnect the sensor and see if it advances to where it should be.

Roy

ASEMaster6371
Sep 16, 2012.
Where should it be?

It came to a steady 4 degrees, then I pressed the gas and it jumped again ffrom 4 to 2 to 3 to 4

How did you know is was 4 degrees retarded if you dont know where it should be?

4 degrees before top dead center is the spec.

Roy

ASEMaster6371
Sep 16, 2012.
Its just stopped at zero

How did you check the timing and when did you check it?

Roy

ASEMaster6371
Sep 16, 2012.
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