Any way to trick the computer?

[ellero]

Heres the deal. I changed out my 700R4 for a T-350. The 700R4 had 2 extra sensors that the T-350 doesnt have. Since there is nowhere to plug them into, the check engine light comes on from the computer throwing a tranny code. Can I loop out this sensor or some how trick the computer into thinking the tranny is plugged in with a resistor of some sort? If so, how? The county where I am moving does not do any inspections or smog so I never have to worry about that. I can always take out the check engine bulb, but I kind of want to have it in there in the event that I have any engine trouble. Any help on this would be great.

Thanks,

John

 

[tennyohpc]

well it should be possible to do but you would need to know exactly what the sensors are and what the internal resistance value they were during normal operating conditions. i will look and see what i can find. is it the actual 700r4 or the newer version of the 700r4 cause i dont think the older ones had sensors.

 

[73K5Kid]

well it should be possible to do but you would need to know exactly what the sensors are and what the internal resistance value they were during normal operating conditions. i will look and see what i can find. is it the actual 700r4 or the newer version of the 700r4 cause i dont think the older ones had sensors.

From what I gather he is no longer running a 700r4 and is running a t-350 3sp automatic trans. He is trying to bypass the sensors to not throw a tranny code since he is no longer running the 700r4.

 

[lectric80]

I would guess it is the 4l60e as most of the 700's I have seen don't have any type of sensor on them, unless you count the speed sensor on the two wheel drives.

 

[dremu]

From what I gather he is no longer running a 700r4 and is running a t-350 3sp automatic trans. He is trying to bypass the sensors to not throw a tranny code since he is no longer running the 700r4.

As said, sure sounds like a 4L60E.

Either that or they aren't sensors in a complicated sense, more like VSS or something.

What year truck is being discussed?

-- A

 

[Currank5]

I ditched my 700r4 for a 4spd manual. I tied off the plug somewhere and i've never had any check engine light or any codes of any kind.

 

[Russell]

What type and year of rig are we talking here? Early 90s 4x4 Blazer, 2wd, or what?

 

[cabledawg]

If its for the 84 K5, then the two things you unplugged were the TC lockup and the VSS. Should have been a third plug for the 4x4 indicator light. Not sure on that one though. My 700 was from a 90, so it had the dash light that lit up when the tcase lever went into 4hi or 4lo.

 

[4X4HIGH]

The 4WD indicator light is wired from the t-case, not the tranny.

 

[Blue85]

I thought for all trucks, even California, the VSS from the tranny started in 1990. Before that VSS was generated by the speedometer.

This must be a CCC truck. There were several variations of wiring for the 700, so it's hard to say for sure what you have without dropping the pan. Some have pressure switches to indicate the TCC has locked. Plus the ECM COULD look for the resistance of the lockup solenoid. I'm not familiar with the CCC vehicles.

Does the ECM control converter lockup on CCC trucks?
Are there two harnesses coming from the tranny or just one?

 

[dyeager535]

VSS AFAIK was never on the transmission. Only years that could have been possible were 1990/91, and only on any old body style truck that could have been 2WD. (Sub, crew cabs?) I've never seen it, but could have existed.

In any case, I'm expecting this is a CA CCC vehicle, and the TCC is computer controlled. Odd that there are two plugs on it though, never heard of a TCC app using two plugs, that four prong single plug was standard on all GM TCC transmissions at least until the 4L60, probably even later, the 4L60E/4L80E.

 

[ellero]

From what I gather he is no longer running a 700r4 and is running a t-350 3sp automatic trans. He is trying to bypass the sensors to not throw a tranny code since he is no longer running the 700r4.

Thats exactly what I am trying to do. I can clear the code by disconnecting the battery, but after I go faster than 25 mph and stop twice (because its a 2 stage code), it will throw a tranny code and on comes the check engine light again. This I found out from the local smog tech, but he leagally could not tell me how bypass it.