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I'd like some help in setting up a 12200411 LS1B PCM for 700R4. I've done this before but forgot what I had to do? This one is a little more complicated by VSS that is an 8. So need to calculate that for proper speed which is needed for the TCC operation.
Yes I know someone would do it for me, but that's not what I'm looking for. Looking for the knowledge to do it correctly and understand changes needed. This one will be done in EFI Live and the RoadRunner.
Hi Mark,
Post the base tune you will be beginning from (in *.tun format) and I will work through the changes with you. I should have time to reply back and forth with you this weekend ...
Thanks Buzz! This should be a good lesson! :thumbsup:
Truck should be here tomorrow for the weekend so I can read it.
I'm wondering if the 700R4 has been modified? I've worked with a few 700R4's that had some internal wiring modifications done to allow a manual toggle switch to lock up the torque converter.
What I remember about OBD I 700R4 TCC control ... when the 4th gear switch closes a ground is sent to the ECM. The TCC solenoid gets power from the brake switch. When all programmed parameters are qualified (usually TPS / MPH), the ECM will apply a ground to the TCC solenoid.
I'm thinking EFI Live can be programmed to 100% PWM Min / Max for TCC control. I'm thinking MPH can be programmed for TCC lock up. I'm thinking most LS1B wiring I've worked with have Red 42 as TCC control.
dave w
It's a stock 700R4 that came in the 1990 Blazer. Not sure what he did with the wiring yet? The only thing I did a few months back was remove VATS when he was installing the engine. It does run and drive.
For the VSS, it's a Dakota digital 8k on NP208/700r4 adaptor.
i don't know if referring to full-size blazer or the S10 blazer, but in either case.... looks like the same diagram used between a 4.3 blazer S10 and a 5.7 full-size S10.
can probably ignore the TH400 section.
brake switch is wired in series with the TCC solenoid, so brake application should always disable TCC, otherwise some kind of trans issue exists and is keeping it engaged.
the way the temp and 4th gear switches are setup in the other diagram are kind of confusing, but maybe there is some reasoning behind it? not enough digital inputs available to watch them seperately?
http://imgur.com/f7drJku,4MzqsK8
It's a full size Blazer. I'm pretty familiar with the wiring on that end, just forget what to do on 1220411 end? He says it's done, but I like to make sure things are done right and check operation, considering there's no noticeable sign of TCC lock up? But with the wrong VSS signal who knows what the speed is recording? I've never driven it and months ago it was a truck without a motor, 5.7L TBI and 5.3L sitting on floor.
Do you happen to have that second page as a full page? I don't have that diagram...
I think adjusting the Speed Pulse Per Revolution will correct for the Dakota Digital 8K pulse. The idea I have is to get the Speed Pulse per Mile to be 8000. Here is the link to a post I did about a week ago: http://www.gearhead-efi.com/Fuel-Inj...gital-SEN-01-1
I don't know if this really works, because the vehicle I flashed the PCM with these changes is not on the road yet.
dave w
I tried this once before, didnt make it work so I hooked it back up through the vacum switch. I believe the pcm needs to see the vehicle in gear before it will apply the tcc. Not having a prndl switch it will not see in gear. Might be able to make it work, I just found it easier to leave it with brake switch, vacum switch, 4th gear switch setup.
Lots of good ideas in this thread already ...
Dave W - you figured it out (despite your lack of a road test) - with a pulse generator (typically being driven by a speedometer cable) would want the VSS pulses per mile (H0101 in EFILive) in the tune, to equal that of the pulse generator (4K / 8K / 16K). It doesn't matter what speedometer parameters you change to arrive at this value - as long as in the end the correct value is displayed.
The PRNDL tells the PCM what position the gear shift is in - not what gear the transmission is in - there are two different PIDs in the EFILive ScanTool that correspond to gear shift position (GM.PRND) and the current gear the transmission is in (GM.GEAR). You could get an input to the PCM for the gear shift position with a 700R4, but not for the current gear (as it is a non-electronic transmission).
TCC lockup ... is another issue ... most people who run a non-electronic transmission (TH350 / TH400 / 700R4) behind an LSx engine with a PCM, will either run a manual transmission tune, or an automatic tune with pretty much everything disabled. Obviously, a manual transmission tune cannot control the TCC lockup. An automatic tune could do this - but not without a proper transmission current gear signal - which the 700R4 cannot provide.
Most people elect to simply have the 700R4 lockup in 4th gear only, as already described in this thread. Unless the vehicle is underpowered, or will be used for towing, there is no need to use a vacuum module as a component of the TCC lockup system. Ignition voltage routed through a brake pedal switch works just fine.
There is another option which I have never tried (I don't get much call for non-electronic transmissions) ... running an automatic tune, but with the transmission type changed from 4L80 or 4L60 to "non-electronic automatic". I wonder if this MAY let the PCM control TCC lockup based on VSS only ... who knows
i could grab it, but boy is it large, ugly and confusing for me. it was from the S10 blazer though.... can't find that exact style for the 90 full-size. different years.... maybe.Quote:
Originally Posted by EagleMark
Thanks but no need. Only interested if it was for 7747 type ECM.Quote:
Originally Posted by RobertISaar
90 blazer S10 4.3 might be 7747?
Same C3, probably a 288 or 299? I'd like one for that if 700R4? If it's huge and hard to work with like you said we'll just pass.Quote:
Originally Posted by RobertISaar
Buzz, mecanicman, Dave, thanks, I think I got it for the VSS.
But TCC will only work in forth? With no speed? This I'm not clear on... I could get only one signal from P/N is grounded, when in D/R it is an open signal, could run that through relay. But no more, couldn't get all gears.
Actually forth is fine and not even going to shoot for third. Truck has good gearing for 35 inch tires but I've had enough of these to know third is not worth it.
http://i.imgur.com/5GbtscH.png
for some reason, i didn't rotate before uploading....
anyways, that style of diagram confuses almost as badly as the stuff chrysler released for most of their OBD1 vehicles.
Thanks Robert!
Back to 700R4 and lock up only in fourth gear...doesn't it need some kind of VSS from PCM to lock? This vehicle trans was controlled by ECM that has speed, no vacuum switch which IIRC only came in pre 87 Chevy Truck 700R4.
Vacuum switch was weird on those old 700r4s. It was only used for 2nd and 3rd gear lockup as a pressure switch controlled 4th gear lockup.Quote:
Originally Posted by EagleMark
The 700R4 shifts are 100% mechanical (not controlled by any PCM / ECM). The TCC lockup is a simple 12 volt supply (no PWM etc.). It can be as simple or as complicated as you wish.Quote:
Originally Posted by EagleMark
The most simple means is a 12 volt ignition circuit, routed through a brake switch that interrupts the voltage, connected to a normal open pressure switch on the 4th gear circuit of the valve body (most / all 700R4 came with this switch in place). With this method the TCC is locked in 4th gear at all times - except when the brakes are applied.
The next most complicated method adds a vacuum switch, which interrupts the the voltage when the vacuum drops (under load).
The most complicated method adds a speed component - which in a TPI / TBI vehicle was controlled by the OBD1 ECM. If memory serves B&M used to offer such a kit.
As long as the vehicle is not dreadfully underpowered the most simple method works just fine.
Except the simple method is a great way to smoke the tcc linings.Quote:
Originally Posted by Buzz
The 5.3L should do fine even with the 35 inch tires as it was re-geared to 4:88 gear ratio. Although the aerodynamics of a brick at highway speed is a factor.Quote:
Originally Posted by Buzz
So at 70 MPH should be forth and TCC locked I think it'll be fine. Now start pulling a mountain pass and? Seems like this is where the simple switch to unlock could be a benifit? If not it may be a lot of throttle and a harsh downshift to third?
How's that?Quote:
Originally Posted by Fast355
I could see if it were used improperly... or am I missing something?
Keeping the TCC locked up at highway speeds reduces / eliminates TC slip, and thereby reduces overall transmission temperatures.Quote:
Originally Posted by Fast355
The OEM strategy generally follows this principle.
In the late 1980s / early 1990s I ran a 355 / 700R4 combination in as S10 pickup wired just like this - 200K later when I sold it, the drivetrain still worked just fine.
I've successfully used the Superior Transmission K058 ( http://www.superior-transmission.com...age.cfm?ID=186 ) with a modified 700R4. The 700R4 had been modified so a manual toggle switch (wired in series with the brake switch) could be used to lockup the torque converter. The vacuum switch replaced the manual toggle switch.
dave w
Well since Dave has one solution I figured I'd add another idea to this thread for future reference. It may be the answer to all proper signals of gear postion to 0411 to operate TCC lock in 2 through 4 if someone wanted to spend $100.
http://www.dakotadigital.com/index.c...prod/prd60.htm
In post #10 I mentioned that the PCM receives an input from the transmission with respect to the current gear the transmission is in. The PCM may also receive an input from a transmission mounted Park / Neutral Position Switch with respect to the current shifter position. These are not the same thing.
For example, with the shifter in the 4th or overdrive position, the transmission is free to shift up and down through all 4 forward gears - the shifter position however would have never changed.
That kit could send a signal to the instrument cluster to show what position the gear shift was in, but this is not synonymous with the gear that the transmission may be in.
The short answer is - that kit will not be of assistance with respect to TCC lockup.
Bringing this one back from the dead since I am wondering if you guys ever got a 411 to control the TC lockup on a 700R4. I am swapping out a LT1 for a 5.3.
I know I can easily control lockup with a switch (already have this) but ECU control would be cool so I don't have to remember to flip the switch.
I have often thought that if we had access to all of the EGR parameters that we might be able to use the EGR circuit to control TCC. That may be a goofy thought but, it won't go away.
Jeff
I sent the information below in a PM. Hopefully, when others find this tread in the future, the information below will help.
dave w
Likely the only way an '0411 would be able to control a 700R4 TCC is in 4th gear only.
The TCC information below is from the "Internet"
https://www.youtube.com/watch?v=QCFOphXfEbQ (Includes Vacuum Switch, hopefully the 4th gear only TCC harness is sold separately)
Site Unknown
"Set the TCC duty cycle max table to 100 & the TCC duty cycle min table to 90. This is to eliminate the TCC slip, nothing to do with rpm oscillation. You may have to raise the TCC lock up speed. With a cam like your's, there will be low rpm light throttle surge. Tuning will help, but will not completely eliminate low rpm surging/bucking."
Site Unknown
"From the factory the PCM pulses the pressure solenoid for the torque converter lockup to maintain slip and engage smoothly. To disable it you simply set the entire max table to 100% and the entire min table to 99%. This will make the torque converter act like an on/off switch which is disabling the PWM."
Site Unknown
"You should set the entire "PWM" table Min to 98 and the Max to 100%"