locostuntguy

Having problems with my Ls swap. I used a 4L60 out of a 96 Impala, it has been rebuilt before i put it in. I modified a 99 truck harness. The computer was from a 99 5.3 truck, but i have not verified the part number. The tune in the PCM says it is a 99 camaro comp.

After tune, seems like everything works. Except the tuner could not get the torque converter to lock up. When the key is turned to the on position, there is a solenoid clicking in the trans. This goes away when engine is running. We plugged in another valve body, outside trans, and it clicks also.

There were other problems with the trans in initial tune. When placed in drive, it would not go to first gear. It seemed like it was starting off in 2nd or 3rd. You could pull the shifter into 1st, and it would be in 1st, but would not shift. I'm not sure what he did to fix it.
He also did say that when he turned off 3rd gear solenoid, the clicking would stop.

Anyone have any tips or advice on this?

Old Geezer

iTrader: (3)

Pulse width modulation, [PWM cast on the ft pump?] Early vs late trans have different control systems.

locostuntguy

Pretty sure it had a P cast in the front. The guy that sourced the trans for me made it a point to look for something on the pump, i can't remember what for sure. I know it is a K case, and a 4 bolt tail housing.

flame

iTrader: (13)

Sounds like a wiring issue start tracing wires

gofastwclass

iTrader: (2)

The PWM that Old Geezer referred to earlier is cast on the front pump inside the circle.



Closeup of same.



I'm not sure the Gen III PCM can control a 96 Impala transmission and lockup torque converter properly without a full wiring upgrade to the transmission.

On the other side of the coin, I know there are some 96 transmissions that are properly equipped in factory form, I just don't believe they were in Impalas. More important, the PWM (or 6 tailshaft bolts on the 97+) is the only way I know to spot one.

LS1MCSS

iTrader: (18)

From what I can find out, by doing a little research, it looks like 95 was the first year for PWM transmissions. If yours is PWM then you should be able to make it work.

locostuntguy

It is a pwm.

locostuntguy

Quadruple checked wiring tonight. Used reputable online source to double check pinouts of pcm and trans plug/ pinout.

I'm sure about the wiring. Looks like next option is new pcm, and have it flashed as a 99 truck from the tuner that I am working with.

flame

iTrader: (13)

Are the pcm pinouts the same truck to car? I would double check that since you have a truck harness and car OS in the pcm.

gofastwclass

iTrader: (2)

Automatic transmission pinouts are the same truck to car, but if the car OS was a manual some of those pins are shared and have different functions. This means the trans may not shift or lockup or whatever. I don't have access to my wiring diagrams but that could be your problem.

You either need to reflash with an OS that is for the 4L60E or send the file to HP Tuners (if that is what you are using) and have them segment swap to an automatic.