Hello my name is Joe and I just joined this forum after purchasing a clean 1990 Fleetwood Brougham with 307 Y motor and 200 R-4 trans. The car sat for a few years and thus now has the well known TCC shuddering lockup issue after driving the car for about 10-15 minutes when fully warmed up. I pulled the pan and replaced the solonoid with a Pro king from Advance Auto parts, refilled with new fluid and filter and now the bloody TCC solonoid is coming on all the time, hot or cold. There is no check engine light, hitting the brake pedal lightly turns it off for a few seconds and then it comes right back. For now I disconnected the connector on the side of the tranny until this is resolved. Has anybody come across this before? Thanks for any replies and help.
If unplugging it fixes it, then you need to consult a wiring diagram. If memory serves, the solenoid is activated by the PCM completing a the ground side of the circuit. The solenoid always has 12V+. The only thing that interrupts the 12V+ is the brake pedal switch. Again this is from memory on my GN, but I'm pretty sure this is the case. If I'm right, then the problem is that you have the TCC always grounded. A likely cause is a chafed wire inside the trans. As I'm sure you noticed, the wire for that solenoid runs through a couple of metal looms bolted to the valve body.
Again, you'll need to consult a wiring diagram, but I think you'll find that you can check the plug on the outside of the trans for a ground. If it's grounded, that's your problem.
If you go to www.gnttype.org and find your way to the Technical Resources section, there's a lot of information on TCC troubleshooting for the 200-4R.
You can leave the solenoid disconnected. The only thing it does is slightly increase your fuel economy (about 1-2 MPG over the course of a tank). It also helps the transmission cool down by eliminating slip in the drive-line, but the transmission cooler will compensate for any lack of cooling. Unless you use the car for towing or drive hours on the highway everyday, driving without the TCC will cause no adverse effects.
I would plug it back in, but clip the hot TCC wireif you don't want the lockup. There's 2 other wires on the connector for 3rd and 4th gear switches that report to the PCM. Not sure why the PCM needs to know this, but it must use the information for something.
Thanks guys. My friend is going to bring his analyzer and plug my car in and see if anything shows up. He thinks maybe the 4th gear pressure switch is bad and wants to check things out with the connector plugged back in. I'll post findings here when I know more.
The 4th gear switch won't affect TCC lockup. I believe it's only for the PCM to make timing and fueling decisions. TCC lockup is purely a function of MPH and throttle position. Due to the fluid path, lockup can only occur in 2nd through 4th gear so the PCM doesn't use the 3rd or 4th gear switch input in the lockup decision.
It sounds like yours is locking up as soon as its physically able to. That is, as soon as the fluid path allows it on the 1-2 shift. If unplugging the solenoid causes it to stay unlocked, and hitting the brake unlocks it, then the solenoid is working as it should. It almost has to be a problem with the wiring somewhere.
It's a long shot, but there is a wire on the ALDL that when grounded causes the TCC to lockup. I forget what position in the connector it is. Maybe yours is grounded for some reason?
Have your bud use the scan tool to check for when the PCM calls for lockup versus when it's actually happening. I'm sure you know by now, but the lockup feels like another shift, but if it's too early it will bog the engine down.
The TCC goes to pin F on the ALDL. When you look at the connector, it's the one on top row, left hand corner.
Looking at the wiring diagram in my manual, it looks like the computer used the wire at that terminal to supply ground to the solenoid. The TCC also receives inputs from the 3rd and 4th gear switches, so Jimmy is right that if the wire from that terminal was shorted to ground, the symptoms would be as you describe. You or your buddy can test the terminal with a test lamp by cliping the lamp to battery power and back probing the F pin; if the lamp lights, the wire is shorted to ground.
You mean PCM, not TCC right? The 3rd and 4th gear switches aren't involved in the lockup decision.....as far as I can remember.
It's been a while since I messed with a 200-4R and I've tried to block the experience out of my head. It was a 14-second transmission bolted to my 10-second engine. I spent thousands and thousands of $$ beefing up 200s and never did get one that held up. There's only a handful of guys in the U.S. that can beef them up. One of those guys is NOT in Long Island, NY. Just sayin.
The ECM uses the 4th gear switch as one of the inputs to determine the application of the TCC. It is not the only thing the computer considered (such as the VSS), but the 4th gear switch is the primary input.
Here is a diagnostic chart for the TCC:
**Disregard my original test for your TCC; the F pin is not grounded like I prevously thought.
The ECM uses the 4th gear switch as one of the inputs to determine the application of the TCC. It is not the only thing the computer considered (such as the VSS), but the 4th gear switch is the primary input.
Here is a diagnostic chart for the TCC:
**Disregard my original test for your TCC; the F pin is not grounded like I prevously thought.
I'm not trying to be dense or argumentative, but I don't see anything on that chart that talks about the 4th gear switch. I don't want to send someone down a diagnostic rabbit hole. Now I am applying my experience with my Grand National to this problem, but that diagnostic chart looks the same. The GN didn't use input from the 3rd or 4th gear switch in TCC decisions. I'll readily admit, however, that the GN is not a 1990 Cadillac ;-) . Caddy may use different algorithms in TCC decisions.
However, per the chart the two key inputs the ECM uses are speed and throttle position (as I said earlier). And, the TCC gets is 12V+ from the brake switch which (as I said earlier). I'm struggling to figure out why it would care whether the car is in 4th gear or not. It would only matter if lockup only occurred in 4th gear. I'm ASSuming that the TCC locks up in any gear, 2nd through 4th. I've tweaked hundreds of fueling tables for the GN and while the ECM doesn't use the 3rd and 4th gear switches in TCC lockup decisions, it DOES use a combination of inputs (3rd gear, 4th gear and whether the TCC is locked or not) in fueling and timing decisions. For example, you'll get different fueling and timing in 4th gear if the ECM has called for a locked converter versus not. Actually, I would cut back the timing on the GN when the converter locked in 3rd gear to avoid detonation due to the additional load (didn't use 4th gear at the track).
I think you were correct in your ALDL Pin F check, though. If you use a continuity tester and find that Pin F is grounded, then you have a wiring problem somewhere. It should not be grounded unless the PCM has called for lockup. If it is grounded, that means that the TCC solenoid circuit is closed and the torque converter will lockup up as soon as it physically can (as soon as the trans gets to 2nd gear).
I had a switch in my Grand National that would ground that wire to force a lockup of the converter at wide-open throttle around 75-80 MPH. I had a Vigilante converter with a 7-disc torque converter clutch in it and it felt like someone rear-ended me when it locked. Locking it was good for 2-3 MPH in the 1/4-mile and also eliminated the natural torque converter slippage to keep RPMs down at the end of a run (to avoid having to shift into 4th gear). It's also really obvious when I forgot to flip the switch back: the car would bog as it downshifted going down the return road. I suspect this is what the OP is feeling - that solenoid is locking the converter all the time for some reason.
The 200-4R is a weird gear box... They slapped it behind so many different engines, for so many different applications that it is hard to figure out what everything does.
Is it possible this thing thinks it's overheating and is commanding the TCC on to reduce overall heat load? If that strategy is in there, it might be part of description and operation in CCC for the 307 engine. The idea there is if it sees a hot engine or transmission, it turns on the clutch early, as early as 2nd gear to take away the heat load from the trans cooler until the parameters fall back to where they should be. It could be a bad or biased sensor, or maybe it's got water ingression in a harness pulling the sensor signal low. Just ideas. Good luck!!!
Not sure if the ECM is smart enough to do something like that, but it is a possibility. A scan-tool should be able to bring up the coolant sensor and show what the computer thinks the engine temperature is.
Thanks again for all the good info. My buddy got sick and couldn't make it last week so hopefully we will connect up his scan tool tomorrow and check everything out. Will post what we find out.
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