PCM Firm Shift Mod
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Teching In
Joined: Sep 2002
Posts: 4
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From: Lubbock, TX
PCM Firm Shift Mod Dont hold me responsible for broken tranny mounts, bald tires or any other damages!
This mod is for 4L60E or 4L80E only! Use a triple throw switch. In the first position, use a resitor with a 27.2 ohm value. (Position 1 firmness) The second position, use no resisitor. (Off position) The third position use a 5.2 ohm resistor. (Position 2 firmness) Remember all this mod does is change the amount of current going to the pump. The less resistance, the more current to the pump, which equals a harder shift. Beware this could cause pre-mature failure of your pump overtime. If you really wanted to get kinky, you could always run position 3 straight, without a resistor for a killer shift. (Race only) Anyways, back to install. Remember 98 & up 4L60E's, the car should be off before putting the switch in the desired position. Now find your (White harness) on your PCM. Connect to terminal #36(Light Blue w/White stripe) for position 1. Connect to terminal #39(Red w/Black Stripe) for position 3. Mount your switch & your done. All feedback & questions welcome!
This mod is for 4L60E or 4L80E only! Use a triple throw switch. In the first position, use a resitor with a 27.2 ohm value. (Position 1 firmness) The second position, use no resisitor. (Off position) The third position use a 5.2 ohm resistor. (Position 2 firmness) Remember all this mod does is change the amount of current going to the pump. The less resistance, the more current to the pump, which equals a harder shift. Beware this could cause pre-mature failure of your pump overtime. If you really wanted to get kinky, you could always run position 3 straight, without a resistor for a killer shift. (Race only) Anyways, back to install. Remember 98 & up 4L60E's, the car should be off before putting the switch in the desired position. Now find your (White harness) on your PCM. Connect to terminal #36(Light Blue w/White stripe) for position 1. Connect to terminal #39(Red w/Black Stripe) for position 3. Mount your switch & your done. All feedback & questions welcome!
TECH Enthusiast
Joined: Jul 2002
Posts: 731
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From: dyersburg,tn
Re: PCM Firm Shift Mod I have already turned the solenoid 1/4 turn no improvement.I had a friend put the b&m on a 99 and it didnt work right.I called b&m and they said the shift plus would not work right on a 99 up 4l60e.I have a question on the resistors.How close to the ohm value? I went to radio shack and found only a 28 closest to 27.2 and I could find a couple of them close to 5.2 but no 5.2.Help me out here.
