* FIXEDManually locking TCC A4LD?

[Nadams01]

Hey all, I've seen a couple of forums about this topic, none really go into great depth on install or differences in driving or what not so I figured I would give it another shot. I have a A4LD that was just built by a trans shop here in CO. HD clutch packs, shift kit new tourqe converter and I'm running a transcooler out of a f250 after my factory aux cooler. I have a gauge running before the coolers as well. I wanted to have a manual override of the TCC because one of the variables for the PCM to ground the signal locking the solenoid is a MAP below 23.5 InHG. issue being I often drive at higher elevation where the atmospheric pressure is lower than that, preventing the tcc from locking. I tapped into pin 53 which is a white wire, I left the wiring that runs to the solenoid and T-d it to a switch. Positive side of the switch is connected to the white wire then I ran a ground which is tied to a couple other grounds. Essentially im telling the solenoid that its grounded even though the pcm is not. Is my wiring theory correct? Or am I interfering with the signal of the pcm by simple teeing off from the wire that feeds from pin 53 to the solenoid. When I flip the switch it feels like it locks up, but unlike the pcm doing it it feels sluggish and almost like its running rich, i can smell excess gas. Any ideas? Thanks all.

 

[Nadams01]

Hey all, I've seen a couple of forums about this topic, none really go into great depth on install or differences in driving or what not so I figured I would give it another shot. I have a A4LD that was just built by a trans shop here in CO. HD clutch packs, shift kit new tourqe converter and I'm running a transcooler out of a f250 after my factory aux cooler. I have a gauge running before the coolers as well. I wanted to have a manual override of the TCC because one of the variables for the PCM to ground the signal locking the solenoid is a MAP below 23.5 InHG. issue being I often drive at higher elevation where the atmospheric pressure is lower than that, preventing the tcc from locking. I tapped into pin 53 which is a white wire, I left the wiring that runs to the solenoid and T-d it to a switch. Positive side of the switch is connected to the white wire then I ran a ground which is tied to a couple other grounds. Essentially im telling the solenoid that its grounded even though the pcm is not. Is my wiring theory correct? Or am I interfering with the signal of the pcm by simple teeing off from the wire that feeds from pin 53 to the solenoid. When I flip the switch it feels like it locks up, but unlike the pcm doing it it feels sluggish and almost like its running rich, i can smell excess gas. Any ideas? Thanks all.

Update: I have isolated the ground to its own source, hopefully the tcc solenoid fully engages as intended. Will be writing a indepth guide after I figure it out.

 

[Nadams01]

Update: I have isolated the ground to its own source, hopefully the tcc solenoid fully engages as intended. Will be writing a indepth guide after I figure it out.

Update/ bump. I regrounded to the floor of the vehicle. I just tied in a 3rd wire to the tcc ground signal so it looks like a tee idk if that's the problem. I am using 18 gauge wire. What happens is I can feel the pcm engage the tcc at 50 mph. No slippage and plenty of power. Then I will proceed to flip my switch 35 amp btw and it bogs down and runs rich. This is a 91 a4ld that's built so it's tied to a electrical 3 4 shift solenoid for power. Maybe the pcm changes AFR with tcc locked by the pcm and when I do it it assumes it is unlocked running higher Rpm? If that was the case I wouldn't think by locking it after it locked itself it would run so rich. I can lock it ad idle and it will still run very rich. I believe the inputs for pcm to run signal to tcc is BARO tps vss ect boo. Anybody know anything ? I'm determined now.

 

[RangerX]

Way over my head, but I hope you get an answer so I took the liberty of adding a question mark into your title to show you’re looking for help.

 

[Nadams01]

Way over my head, but I hope you get an answer so I took the liberty of adding a question mark into your title to show you’re looking for help.

Thanks that might help lol. I'm a apprentice technician so learning about these early obd1 systems is a slight obsession and quite helpful when most guys can't diag anything that's not OBD2. EECIV was certainly complex for the time however flawned in it's nature. Once I figure everything out Im going to write out a guide on how it works and how to troubleshoot it. Maybe somebody can give me parameters of when the pcm tells the tcc to engage but I think only ford knows

 

[Josh P]

The 3 wire plug on the transmission, center is power, The two outer wires are what get grounded by the ecm to activate the solenoids. Most people cut the wire by the connector, reroute it to a switch that goes to ground. I'd advise against wiring it in a T.

 

[Nadams01]

The 3 wire plug on the transmission, center is power, The two outer wires are what get grounded by the ecm to activate the solenoids. Most people cut the wire by the connector, reroute it to a switch that goes to ground. I'd advise against wiring it in a T.

Removing the opportunity for the pcm to lock it own its own? That would make more sense

 

[Micah J]

Would love to know what you figure out. I hate my stupid A4 lol.

 

[Nadams01]

Would love to know what you figure out. I hate my stupid A4 lol.

I'm driving up to Wyoming couple of weeks hopefully I can do some more investigation. Got busy rebuilding the LS rear end I will do a proper write up on it as most info on the forums are plane wrong. Looking at triple throw triple pole switches to 1st engage the pcm signal and ground for factory controll the 2nd to cut the connection between the pcm and tcc and 3rd to manually ground the tcc.

 

[CDW6212R]

Try hard to never apply any signals to PCM wires, they are very sensitive to higher currents etc, most all are low current and grounds.

Try to isolate the PCM signal wire, by putting a simple OEM small relay in that one wire. Then you can apply your added ground on the side of the relay not connected to the PCM.

The real problem sounds like it may be the computer altering A/F based on what it perceives is the current rpm. I don't know how well those EECIV PCM's adjust for altered conditions.

 

[Nadams01]

Try hard to never apply any signals to PCM wires, they are very sensitive to higher currents etc, most all are low current and grounds.

Try to isolate the PCM signal wire, by putting a simple OEM small relay in that one wire. Then you can apply your added ground on the side of the relay not connected to the PCM.

The real problem sounds like it may be the computer altering A/F based on what it perceives is the current rpm. I don't know how well those EECIV PCM's adjust for altered conditions.

 

[Nadams01]

I think I have it figured out hopefully. Going off the pcm changing AFR based on what it perceives to be RPM, I doubt the pcm has a AFR setting for just when it sends a signal to the TCC but a universal amount that would sense a drop after the TCC is engaged. I think the way I had it wired was the problem, the ground that I manually switch running back into the PCM instead of isolating that signal. So using a Single Pole Double Throw on, off, on switch that uses 3 poles we can isolate our artificial ground and the signal from the PCM. excuse my poor diagram I will make one on the computer later. Pole 1 being is the signal wire from the PCM. Pole 2 is the ground to the TCC solenoid and Pole 3 is our artificial ground. With the switch in the 1st on position, the PCM signal wire is connected to the TCC ground wire and acts as factory. If we flip into Off, the connection between the PCM and the TCC solenoid is broken and the converter will stay off. In On 2 we are artificially grounding the TCC. This way no contact or interference is generated to the PCM hopefully solving the AFR problem.

 

[Nadams01]

I think I have it figured out hopefully. Going off the pcm changing AFR based on what it perceives to be RPM, I doubt the pcm has a AFR setting for just when it sends a signal to the TCC but a universal amount that would sense a drop after the TCC is engaged. I think the way I had it wired was the problem, the ground that I manually switch running back into the PCM instead of isolating that signal. So using a Single Pole Double Throw on, off, on switch that uses 3 poles we can isolate our artificial ground and the signal from the PCM. excuse my poor diagram I will make one on the computer later. Pole 1 being is the signal wire from the PCM. Pole 2 is the ground to the TCC solenoid and Pole 3 is our artificial ground. With the switch in the 1st on position, the PCM signal wire is connected to the TCC ground wire and acts as factory. If we flip into Off, the connection between the PCM and the TCC solenoid is broken and the converter will stay off. In On 2 we are artificially grounding the TCC. This way no contact or interference is generated to the PCM hopefully solving the AFR problem.

 

[CDW6212R]

That will work. I wired in that kind of switch for my mail truck's turn signal on my RF door, just as a grounding control, through relays of course, with diodes in the OEM circuits.

 

[Nadams01]

View attachment 331673

Ah yes. Stumped again. Not sure how this is even possible but the 1st setting which contains factory operation works as intended. 2nd position which is supposed to disengage the tcc altogether locks up the converter and repeats as before and the 3rd stage is exactly the same. Best guess is that switch isn't wired how i wanted internal and no surprise it didn't come with a diagram so gonna try again with a actual on off on switch (thanks AutoZone).

 

[imp]

Removing the opportunity for the pcm to lock it own its own? That would make more sense

Ford unlocks TCC every time throttle is allowed to close, (no gas pedal depress). This fact always irks me.

Second, TCC lockup occurs AFTER highest gear is attained, it's the last thing to happen. Then, if added power is called for, at highway speed (~ 50+ mph) TCC UNLOCKS, trans remains in highest gear. If more power is called for, TCC remains UNLOCKED and trans shifts down to next lower gear from high gear. With my 5-speed auto, 5R55S, it can operate in 3rd. gear with TCC locked (according to literature) but I've never gotten it to do it.

I would like a manual TCC switch. If left ON, engine would stall at complete stop. Drawback #1.

If TCC desired ON when PCM calls for OFF, it will throw a CEL, no way around that. Ditto disconnecting PCM feed to TCC solenoid. Drawback #2.

 

[CDW6212R]

Ditto, altering the transmission wiring from what the PCM expects will throw an error code. It's fine to temporarily do it for diagnostics or short term uses.

I installed two relays and a switch in my 95 Crown Vic to disable 3rd gear, also for 4th, for mail delivery. That's the 4R70W four speed, and I didn't want the car shifting into 3rd when I was constantly slowing down and stopping. That worked great for me, but it did throw a code after a short while(during the day). It had no long term affects, and the error code would go away after a month or so of normal driving.

Keep experimenting, but be careful.

 

[Nadams01]

Ford unlocks TCC every time throttle is allowed to close, (no gas pedal depress). This fact always irks me.

Second, TCC lockup occurs AFTER highest gear is attained, it's the last thing to happen. Then, if added power is called for, at highway speed (~ 50+ mph) TCC UNLOCKS, trans remains in highest gear. If more power is called for, TCC remains UNLOCKED and trans shifts down to next lower gear from high gear. With my 5-speed auto, 5R55S, it can operate in 3rd. gear with TCC locked (according to literature) but I've never gotten it to do it.

I would like a manual TCC switch. If left ON, engine would stall at complete stop. Drawback #1.

If TCC desired ON when PCM calls for OFF, it will throw a CEL, no way around that. Ditto disconnecting PCM feed to TCC solenoid. Drawback #2.

I'm not sure on the 5r tranny but the a4ld is a hybrid system between hydrollic and electronic. The trans must build suffecient pressure in the valve body to permit locking and unlocking the solenoid. I will nab a picture from alldata when I'm off of work tonight.

 

[imp]

I'm not sure on the 5r tranny but the a4ld is a hybrid system between hydrollic and electronic. The trans must build suffecient pressure in the valve body to permit locking and unlocking the solenoid. I will nab a picture from alldata when I'm off of work tonight.

The system I described is used in the 4R55, 5R55, 5R55E, N, W, and S.

 

[Nadams01]

Ditto, altering the transmission wiring from what the PCM expects will throw an error code. It's fine to temporarily do it for diagnostics or short term uses.

I installed two relays and a switch in my 95 Crown Vic to disable 3rd gear, also for 4th, for mail delivery. That's the 4R70W four speed, and I didn't want the car shifting into 3rd when I was constantly slowing down and stopping. That worked great for me, but it did throw a code after a short while(during the day). It had no long term affects, and the error code would go away after a month or so of normal driving.

Keep experimenting, but be careful.

Ah long reply wanted to do more research as to completely clear this topic up. The switch did not work, same symptoms. Thinking the relay may be the best route. Would I loop the energizing part of the relay back to the pcm? As it would be completing a ground or inturpt the power supply then tie it to the ground signal? Or maybe not even involve the pcm. I'm driving up to keblar pass this weekend. I don't wanna loose my lock up at higher elevations going through 285.