ECM Chip to change shift points
Thread Starter
Instructor
Joined: Nov 2003
Posts: 149
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From: Germantown MD
ECM Chip to change shift points
I have an 84 with an automatic. I read somewhere that you can replace the chip in the ECM to increase the shift points. Around town the trany shifts through the gears to quickly unless I am accelerating rapidly. From what I have read this is fairly normal. Does anyone have any knowledge of these chips, are they worth it, and where can you obtain them. I have adjusted the detent cable, it helped a little, but still not where I would like it.
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: ECM Chip to change shift points (JFMC4)
No, putting a chip in an 84 wont do anything. The ECM controls very little of the transmissions functions. You have to change things internally in 84 to fix that.
In 94-96, yes since the ECM controls the transmission, not in 84.
In 94-96, yes since the ECM controls the transmission, not in 84.
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: ECM Chip to change shift points (JFMC4)
Shift points are only ECM controlled in later cars using the 4L60E transmission. Adjusting the TV cable had a very small impact on the shift points in my '84. It did affect shift firmness. The only real way to change the shift point is to buy a govenor recalibration kit and start fooling with the weights and springs. Good luck, and...
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Le Mans Master
Joined: Jan 2003
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From: Portland Oregon
Re: ECM Chip to change shift points (JFMC4)
A chip in a 84 car doesn't control the transmission at all. It may control the lock up convertor (TCC) if it does anything. I know that in the 85 model year it does control the lock up point, so it may also in an 84. In the 85's the TCC would lock up at an annoying low speed causing the engine to lug once it shifted into 4th gear. Adding a shift kit and changing the lock up point greatly improves reliability and shifting.
Thread Starter
Instructor
Joined: Nov 2003
Posts: 149
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From: Germantown MD
Re: ECM Chip to change shift points (tjwong)
You hit the nail on the head. The chip controls when the ecm tells the trany to go into lock up. maybe I did not explain to well. The trany goes into lockup well to early which is a common problem with earyl C4s, just looking for a way with out putting a shift kit in to delay the TCC lock up.
Race Director
Joined: Sep 2000
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From: The Top of Utah
Re: ECM Chip to change shift points (JFMC4)
OH ! That's a totally different question. I doubt you will see any difference in the TCC operation with a shift kit. That IS an ECM contralled operation. Most chips will alter the TCC activation points. That is about ALL the one I bought did, except make my 1/4 mile times a little slower. Other than a chip, you could install a manual switch. Good luck, and...
RACE ON!!!
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