C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

ECM Location 1985

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Old Jul 26, 2011 | 07:31 PM
  #1  
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Default ECM Location 1985

I just cant find the ECM. i want to change the chip. Please give location and what i must remove to get to it. PLEASE BE DETAILED.
Thanks ALL. Nick
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Old Jul 26, 2011 | 07:52 PM
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Originally Posted by nickpe
I just cant find the ECM. i want to change the chip. Please give location and what i must remove to get to it. PLEASE BE DETAILED.
Thanks ALL. Nick
Remove passenger side lower dash/floor panel. Several phillips screws...
3 or 4?
D/C wire to lite, set panel aside.

Have 10mm socket on 3/8 drive (or 1/4") ratchet with 4-6" extension.

From kneeling on the ground next to the car, try to orient yourself so that you can look UP in the dash from the floor. You will see 2 large elec plugs with retaining clips. These are the ECM harness plugs. Release the clips, gently remove the plugs and tuck out of the way. Look to either side of the plugs receiver (silver box-ECM) to see a 10mm bolt on each side. Remove the bolt and lower the ECM straight down. Note the guide pins on the top end of the ECM that fit into its bracket when re-installed.

D/C battery before d/c ECM harness plugs.
Chip has locking tabs levers...fold them OUT and away. this will in turn raise the chip from the socket usually.
Set new chip in place, NOTE the guide bar on one side. NEVER push it in place. Gently rock it in with slight pressure. PINS get bent very easily. Be certain that its pins are aligned.

Reassemble exactly as it came apart. ECM plugs do not have enough wire to be crossed over each other. Use caution when pushing/pulling harness and other things out of the way for ECM access. Its hell to get it all stuffed back sometimes.

GFL with the lower dash/floor panel screws....
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Old Jul 26, 2011 | 08:05 PM
  #3  
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nickpe
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From: bethlehem PA
Default

Originally Posted by leesvet
Remove passenger side lower dash/floor panel. Several phillips screws...
3 or 4?
D/C wire to lite, set panel aside.

Have 10mm socket on 3/8 drive (or 1/4") ratchet with 4-6" extension.

From kneeling on the ground next to the car, try to orient yourself so that you can look UP in the dash from the floor. You will see 2 large elec plugs with retaining clips. These are the ECM harness plugs. Release the clips, gently remove the plugs and tuck out of the way. Look to either side of the plugs receiver (silver box-ECM) to see a 10mm bolt on each side. Remove the bolt and lower the ECM straight down. Note the guide pins on the top end of the ECM that fit into its bracket when re-installed.

D/C battery before d/c ECM harness plugs.
Chip has locking tabs levers...fold them OUT and away. this will in turn raise the chip from the socket usually.
Set new chip in place, NOTE the guide bar on one side. NEVER push it in place. Gently rock it in with slight pressure. PINS get bent very easily. Be certain that its pins are aligned.

Reassemble exactly as it came apart. ECM plugs do not have enough wire to be crossed over each other. Use caution when pushing/pulling harness and other things out of the way for ECM access. Its hell to get it all stuffed back sometimes.

GFL with the lower dash/floor panel screws....
Thanks for the info. i had the panel off. ill have to take a closer look. i saw what i think is part of my heater or defrost, black in color. must i remove this to get to the ECM
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Old Oct 10, 2018 | 12:48 AM
  #4  
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sharkface
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From: Oxford Conn.
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Cool Description of ECU removal. Hope it's as easy as it sounds. Want to put a Chip in to awaken the Horse Power a little. I was wondering about removing the glove box area above the passenger side . Mine has easy access, I changed the big bulky dash pad for as flat one. Wonder if this would work? Anyway, I think I'll go with your method, my dash looks nice and even with the new cover and would rather not mess with it.
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Old Oct 11, 2018 | 06:14 PM
  #5  
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playsdixie
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From: ft myers FL/Munising MI
Default

Originally Posted by sharkface
Cool Description of ECU removal. Hope it's as easy as it sounds. Want to put a Chip in to awaken the Horse Power a little. I was wondering about removing the glove box area above the passenger side . Mine has easy access, I changed the big bulky dash pad for as flat one. Wonder if this would work? Anyway, I think I'll go with your method, my dash looks nice and even with the new cover and would rather not mess with it.
save your money and the hour of contortions you'll go through getting it out.....plenty of threads here telling you about chips.....lots of us have had them in and threw them away.....
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