4l80 mvb stuck in 2nd gear

[80goldenburb]

Well, im the -th member here to swap a 4l80 into my square body. Sadly, I'm not enjoying it as i wish i could. She's stuck in limp mode. When i down shift back to 1st manually i feel a slight jerk as if it went into first tho

the mvb method used

TERMINALS PINOUT WIRES "A" AND "B" From the pressure manifold are connected together and connected to the ground side of "SHIFT SOLENOID A". TERMINAL PINOUT WIRE " C" from the pressure manifold is connected to the ground side of "SHIFT SOLENOID "B". 12 VOLTS is supplied to the PINK WIRE on the outside of the trans .This will power up the shift solenoids as well as the lock up solenoid.If you want to lock the converter you must run the BROWN WIRE on the outside of the trans thru a toggle switch to chassis ground.

i have the 12v wire from the plug to switched-on 12v. TCC ground is is taped off at the moment. Any ideas?

 

[HotRodPC]

So you've swapped in a 4L80-E. Has it ever worked right since it's been installed or this install issues? What are you using for a controller?

I probably ought to know this, but what is mvb??? New Term to me.

 

[74propu]

Well, im the -th member here to swap a 4l80 into my square body. Sadly, I'm not enjoying it as i wish i could. She's stuck in limp mode. When i down shift back to 1st manually i feel a slight jerk as if it went into first tho

the mvb method used



i have the 12v wire from the plug to switched-on 12v. TCC ground is is taped off at the moment. Any ideas?

If and this is a BIG IF by using the mvb method you are trying to run the transmission without using a transmission controller ? You can power up the shift solenoids but it will just go into limp mode because it don't know when to shift , how fast it is moveing or what gear it needs to be in . You can wire it up to shift with toggle switches but it is a pain in the arss and you have to flip the switch every time to shift gears and reset every stop and flip again to get back up to speed. faster and easy to get a stand alone trans controller for a 4l80e .

 

[HotRodPC]

So method mvb confused me. I get it now. Manual Valve Body, I'm used to Full Manual Valve Body. So this isn't an actual modified to full manual valve body? You trying to make it manual by use of wiring solenoids?

It's always been my understanding, you have to modify the valve body AND wire it accordingly otherwise, you have to use toggle switches like 74propu has mentioned.

Your best bet is to get the TransGo 4L80-E Stage 3 shift kit and modify the valve body to a full manual valve body. Otherwise, you'll need to do the toggle switches like is done in this fine piece of equipment.
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[80goldenburb]

If and this is a BIG IF by using the mvb method you are trying to run the transmission without using a transmission controller ?

Yes, i am. Dont like computers mixed with auto mechanix.

You can power up the shift solenoids but it will just go into limp mode because it don't know when to shift , how fast it is moveing or what gear it needs to be in .

ok so is there a way to disable the limp mode?
Seems like my problem may be another culprit as this guy claims the method i used works to unlock and column shift it.
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You can wire it up to shift with toggle switches but it is a pain in the arss and you have to flip the switch every time to shift gears and reset every stop and flip again to get back up to speed. faster and easy to get a stand alone trans controller for a 4l80e .

It's always been my understanding, you have to modify the valve body AND wire it accordingly otherwise, you have to use toggle switches like 74propu has mentioned.

Yea but there's also guys complaining that they are stuck in limp mode on that wiring method also. i dont have $600 for a controller and if i did it would go into my pontiac 455 build before some electrical hardware box, just sayin.
is there anything else that would make it go into limp mode with both this method and switches? ild hate to do more wiring on this is and then have the same result.

 

[yevgenievich]

Get 3/4 switches, mount them to the on the floor shifter and wire it accordingly if trying to keep with no controllers. So proper switches engauge when you use the shifter. Or early 90's ecm from a diesel truck as it is already stand alone

 

[80goldenburb]

Get 3/4 switches, mount them to the on the floor shifter and wire it accordingly if trying to keep with no controllers. So proper switches engauge when you use the shifter. Or early 90's ecm from a diesel truck as it is already stand alone

i have wired up toggle switches and undone the modified harness connections i quoted previously. 12v (+) to pin E and solenoids are grounded. STILL STUCK IN LIMP MODE. Did i do something wrong?

 

[80goldenburb]

well im surprised no one else has replied yet.
update* ITS NOT in limp mode. i have 1st gear but it stays in it no matter the switches positions or the column shifter selection. What is the cause of this?

 

[yevgenievich]

Could you list the table of all electrical connections? Also check that the plug is not in upside down

 

[80goldenburb]

Could you list the table of all electrical connections? Also check that the plug is not in upside down

A Sol A (1-2) Switched GND (plug---toggle switch---ground)
B Sol B (2-3) Switched GND (plug---toggle switch---ground)
C Pressure Control Solenoid +12V
D Pressure Control Solenoid Switched GND
E +12 Power (plug---switched 12v)
L Temperature Sensor Signal
M Temperature Sensor GND
N Pressure Switch A
R Pressure Switch B
P Pressure Switch C
S TCC Solenoid Switched GND



in RED is what i have wired

 

[yevgenievich]

Pressure control needs to be connected. There are claimed consequences to running full line pressure all the time, I have never wired 4l80e with full line pressure and can't comment on that part
Here is a table for solenoids(copied from one of 4l80e sites)
Shift Pattern Sol A (1-2) Sol B (2-3)
Park ON OFF
Reverse ON OFF
Neutral ON OFF
1st ON OFF
2nd. OFF OFF
3rd OFF ON
4th ON ON

 

[80goldenburb]

Pressure controls are now hooked up. STILL IN LIMP MODE

 

[80goldenburb]

*UPDATE* started checking wires and had no power to switched 12v wire. So i rerouted to the (+) junction block and wallah! solenoids finally started clicking. took her for a test drive all 4 gears are available at the flip of a switch. thanx again

 

[HotRodPC]

So is this using the shfiter and switch method, or just the shifter?

 

[80goldenburb]

Pressure control needs to be connected. There are claimed consequences to running full line pressure all the time

Yup, trans will need a rebuild sooner for those who keep the fixed full line pressure. A homemade pontentiometer/ TPC box is in the works as of now. Will be able to set pressure with the touch of a dial. I would like to set it up tho similar to a TPS sensor where my QJet TV stud pulls a cable and increases/decreases pressure based on throttle opening. That would be a cool idea. i still need the black 94 + force motor.

So is this using the shfiter and switch method, or just the shifter?

Column shifter in "D" and toggle switches.