Check Engine Light - Code #43

trackside

New member
Did the paperclip test and my check engine light is saying code 43. Each time I start it up the check engine light stays on for about 5-8 minutes then goes out and doesnt come back on (even if I shut it off and start it back up again). Now If I start it up the next day, it repeats itself and the light does its 5 to 8 minute thing again then goes out again.Anyone have any ideas what I need to check or fix with this code 43 thing. Im not very mechanical and will probably have to take it to someone in the know unless its something real easy or simple to check or fix. Thanks for all the hgelp and advice you have sent me on previous posts. Thanks again, Jim Butler
 

SYO237

SyTy Registry
Re: Check Engine Light - Code #43

Start with replacing the knock sensor. Make sure you erase all the codes before you install the new one.

Its an easy fix, with the knock sensor located right next to the distributor on the back of the block. Removing the cap/rotor and taking the hood off will make the project go faster. When putting in the new sensor, DO NOT OVER TORQUE. I believe the spec is only around 7-9ftlbs, which basically is snug with your hand.

If you do a search on code 43, you'll find quite a few posts on this subject.




CODE 43
ELECTRONIC SPARK CONTROL (ESC) CIRCUIT
4.3L TURBO (VIN Z) SYCLONE AND TYPHOON (PORT) Circuit Description:
The knock sensor is used to detect engine detonation and the ECM will retard the electronic spark timing based on the signal being received. The circuitry within the knock sensor causes the ECM 5 volts to be pulled down so that under a no knock condition, CKT 496 would measure about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts, DC voltage. The amplitude and signal frequency is dependent upon the knock level. If CKT 496 becomes open or shorted to ground the voltage will either go above 3.5 volts or below 1.5 volts. If either of these conditions are met for about 5 seconds, a Code 43 will be stored.
 
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