hello i have a 1994 S-10 Blazer tahoe 4x4 with the 4.3L vortec v6. I have had or have redone almost every thing on this engine but i keep getting a esc curicit code meaning i getting a intermitant code for my knock sensores or the relay is messed up. i can see the ks on the left cylender bank but there is not one on the right side block like the book says there should be but then again it is really vauge with 4x4 specs. Im pretty sure it should have 2 ks but i may be wrong and if its a short or relay issue how do i go about replacing the relay? Any help tips and suggestions would be wonderful thanks.

 

There should be a knock sensor in both cylinder heads.

Spark control is handled by the ECM in your truck. The only other module is in the base of the distributor.

 

No Hi Jack intended, but I'm having the same issue with my 1993 "W" Blazer 4x. I see the drivers' side KS, but none apparent on the right. Been trying to locate the ECM module, but now I think it's what used to be called the Ignition Control Module? My mechanic buddy gave me a couple of OEM part numbers and they are both KS, but do not look the same.

 

The second knock sensor should be rear of the engine close to the distributor base. Look to the right of the distributor and you should see it, might have to remove plug wires and some vacuum lines to see it.

 

The knock sensor on the right side is hard to see. It's on the rear of the engine up against the firewall above the transmission bellhousing. It's definitely hard to find but it's there.