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1989 Corvette Code 42

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Old Sep 12, 2010 | 08:25 PM
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Default 1989 Corvette Code 42

Hi, My corvette has had this problem for a while now. when you really get on it it tends to miss really bad, so this weekend I hooked it up to my computer and noticed I am getting code 42 (EST monitor error). The corvette does have a hypertech chip (which was there when I bought the car) and I did notice the little cable that goes to the coolant temp. sensor was knocked loose, so I hooked it back up and re-hooked the Vette up to the computer and I still get code 42. Should I just need to reset the computer after I hooked the temp sensor back up if so how do I reset the computer. Help me get this Vette back on the road!! Thanks!
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Old Sep 12, 2010 | 08:34 PM
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Disconnect the neg battery terminal for a minute, that will clear the code.
That code pops up when the EST bypass connector is unplugged for engine timing.
Have you set the timing lately ?

http://members.shaw.ca/corvette86/Code%2042.pdf
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Old Sep 12, 2010 | 09:21 PM
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Originally Posted by AGENT 86
Disconnect the neg battery terminal for a minute, that will clear the code.
That code pops up when the EST bypass connector is unplugged for engine timing.
Have you set the timing lately ?

http://members.shaw.ca/corvette86/Code%2042.pdf
I bought the car the way it is and it has always been ******* on me at high rpm so whoever did the timing (which I am sure it has been messed with) was during the previous ownership.

do you now where the cable is located so I can check to make sure it is hooked up, thanks!!
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Old Sep 12, 2010 | 10:40 PM
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Tan with black stripe wire. Connector is usually inward side of brake booster, near fuel pump relay.
Your symptoms sound like it may be disconnected.
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Old Sep 12, 2010 | 10:52 PM
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Originally Posted by AGENT 86
Tan with black stripe wire. Connector is usually inward side of brake booster, near fuel pump relay.
Your symptoms sound like it may be disconnected.
Thanks, really appreciate it! Ill check tomorrow.
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Old Sep 13, 2010 | 04:36 PM
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I dug around but I cant seem to find the wire, any more details? Thansks
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Old Sep 13, 2010 | 04:53 PM
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Never mind, I rehooked the temp sensor at the bottom of the block and cleared the code like you said by disconnecting the negative terminal for the battery and I hooked everything back up and to the computer, and no code! could that really have been all my problems? amazing what 5 minutes of research and 10 minutes of work can do.

Last edited by C4 Monster; Sep 13, 2010 at 05:22 PM.
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Old Sep 13, 2010 | 07:45 PM
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If you hooked up something at the bottom of the block, that would be the knock sensor. That should have set a code 43.

How does it run now ??
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Old Sep 13, 2010 | 07:54 PM
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Originally Posted by AGENT 86
If you hooked up something at the bottom of the block, that would be the knock sensor. That should have set a code 43.

How does it run now ??
Its not really at the bottom of the block its between the spark plugs on the passenger side (so technically its at the midpoint on the engine and top of the block), I think it hits the water jackets . I will be out for a while and I will be back Saturday and I will give it a run. But it cleared code 42 when I hooked it up and reset the computer so thats somthin!
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Old Sep 13, 2010 | 08:54 PM
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Originally Posted by C4 Monster
Its not really at the bottom of the block its between the spark plugs on the passenger side (so technically its at the midpoint on the engine and top of the block), I think it hits the water jackets :
Ah, that would be the cylinder head, drivers side holds booster fan temp switch, passenger side holds temp gauge sender. Neither would trigger a code.
Maybe the previous owner never cleared the code after setting the timing.
Check to see if the code comes back, after your next drive.
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Old Sep 13, 2010 | 09:17 PM
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Originally Posted by AGENT 86
Ah, that would be the cylinder head, drivers side holds booster fan temp switch, passenger side holds temp gauge sender. Neither would trigger a code.
Maybe the previous owner never cleared the code after setting the timing.
Check to see if the code comes back, after your next drive.
maybe, but a lot of the symptoms im having also have been related to faulty temp sensors from what I read, unless im getting something mixed up, But thats a good point Ill just take it out when I get back and see if it comes up again and I will post back, thanks.
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