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Gm Code 43

bculli05's Avatar

Join Date: Apr 2001
Posts: 82

03-23-04, 01:24 PM   #1  
Gm Code 43

Hi all,
I have a 92 full size cehvy pick up with a 5.7 liter. Throttle Body. The truck recently started running very badly and is throughing a code 43 and 33. Any suggestion on where to start?


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Desi501's Avatar

Join Date: Oct 2003
Posts: 2,207

03-23-04, 02:34 PM   #2  
The code 33 is the important one. It indicates MAP sensor voltage too high. This could be a bad sensor but is more likely a broken or leaky vacuum line supplying it. Inspect the line/hose very carefully all the way back to it's source. Look for any other vacuum leaks that could be lowering the vacuum overall.

The code 43 is a knock sensor code
The ECM did not detect a knock signal during near wide open throttle operation with coolant temperature above 194 F or the knock signal was present for 5 seconds or more during normal engine operation.
Electronic Spark Control (ESC) Circuit .
That one may be a little more complicated. Fix the MAP problem and clear the computer and see if any come back.

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