1993 Chevy Blazer Code 43 ESC Knock sensor

WHHEEZZZZ

MEMBER
1993 CHEVROLET BLAZER
6 CYL
4WD
AUTOMATIC
177,000 MILES

Ok I have code 43 and ive replaced both knock sensors and the wiring to the one on side of block. Getting 4.77volts at connector with sensors unhooked, replaced ECM and prom still code 43 terrible gas mileage 10mpg on highway, no other codes, recent tune up and CPI EGR not clogged I cant get it back to regular timming this code 43 is killing me. Is the knock sensor in the rear next to distributer cap different than side mounted one for resistance, side is 8.3 and back is 9.00 im stumped is the Electronic spark control module located in the ECM? S10 blazer

6 Replies

JAMES W.

MECHANIC
2,394 POSTS

What size V6 do you have. My first check on diagrams doesn't show a knock sensor on your vehicle. Let me know on the engine size and I'll run another search. Please advise.

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Tuesday, March 10th, 2009 AT 4:01 PM

WHHEEZZZZ

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Its a 1993 Cevy S10 Blazer 4.3 Vortec Vin W CPI injection 4x4 I have 2 knock sensors one wire dark blue tonight it was raining very hard and the code went away a couple of times intill it stopped raining then came back on which leads me to a short but the wires are getting voltage specs as stated before thanks

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Tuesday, March 10th, 2009 AT 11:54 PM

WHHEEZZZZ

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Please reply thank you

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Wednesday, March 11th, 2009 AT 10:57 PM

JAMES W.

MECHANIC
2,394 POSTS

You were next on my list. It's midnight here. I was online until 2am this morning. Things are really busy. Anyway, to test your knock sensors with an ohm meter. To ground should be between 3300 and 4500 ohms. To check the circuit, as follows;
With engine at a warm idle, use a voltmeter between the sensor connector and the term on the sensor with meter on the "2" volt scale. Tap on the block close to the sensor with a wrench or small hammer. The needle or meter should move each time you tap. Note, some digital meters don't respond fast enough to show a pulse, just so you know this.
Do you have, or have access to a fax #. I can ship you some information on your ignition. Let me know what you find.

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Thursday, March 12th, 2009 AT 12:09 AM

WHHEEZZZZ

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Thanks for reply, and info, I already checked knock sensor ohms, the side exhaust manifold mounted one is around 8000ohms the rear mounted one is around 9000ohms both brand new, replaced pigtail to side mounted one ill check to see if the voltage is moveing when I tab the block ill get back to you tonight thanks for the help, any way you could copy a txt or pdf file to me by email dont have a fax thanks