1990 Chevy Corvette code 43

Tiny
2SLOW4U
  • MEMBER
  • 1990 CHEVROLET CORVETTE
  • V8
  • 2WD
  • AUTOMATIC
  • 88,000 MILES
1990 vett not ZR1. Have code 43. Most often it set codevery shortly after starting engine. Have replaced knock sensor twice, replaced memcal. Other suggestions?
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Wednesday, August 19th, 2009 AT 7:07 PM

7 Replies

Tiny
BMRFIXIT
  • EXPERT
CODE 43, ESC ERROR WITHOUT ESC MODULE
Test Number 1) If tapping on engine does not produce a knock signal on "Scan" tester, try tapping the engine closer to the sensor before proceeding.
Test Number 2) The ECM supplies a 5-volt reference signal on the knock sensor line. With knock sensor connected this signal is pulled low to about 2.5 volts. Knock signal, which is an AC signal, rides on this 2.5-volt DC signal.
Test Number 3) This test determines if the knock sensor is faulty or if the ESC portion of MEM-CAL is faulty.
Diagnostic Aids
Check knock sensor signal circuit for a potential open or short to ground. An open knock signal circuit would cause the 5-volt reference to remain high at ECM knock signal terminal. A short to ground in the knock signal circuit would cause the 5-volt reference signal to pull low to near zero volts. Resistance to ground through the knock sensor should be 3300-4500 ohms. Also check for proper installation of MEM-CAL.
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Wednesday, August 19th, 2009 AT 8:56 PM
Tiny
2SLOW4U
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I have followed the flow chart in the service manual, replaced the memcal, tried two knock sensors.
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Thursday, August 20th, 2009 AT 11:42 AM
Tiny
BMRFIXIT
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/99387_Graphic1_469.jpg



Sensors was changed and mem cal
wiring checked ok
ECM at fault
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Thursday, August 20th, 2009 AT 6:11 PM
Tiny
2SLOW4U
  • MEMBER
Ordered a remanufactured one, will post again after installing it.
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Saturday, August 22nd, 2009 AT 1:57 PM
Tiny
BMRFIXIT
  • EXPERT
I take it you got the email and the chart I sent to you

good luck
let me know what happens
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Saturday, August 22nd, 2009 AT 5:22 PM
Tiny
2SLOW4U
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Yes got your info, and chart which is basically the same as the service manual. Ordered rebuilt ecm off ebay, will install as soon as I receive it. Once in I will let you know the results.

Thanks
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Monday, August 24th, 2009 AT 6:09 PM
Tiny
2SLOW4U
  • MEMBER
It worked, such a simple fix, but no one who worked on the car ever suggested it. Thanks so much.

Car fixed
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Saturday, October 10th, 2009 AT 11:35 AM

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