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View Full Version : 1993 Celica GT Convertible (2.2L 5S-FE, Automatic) Cruise Control



93celicaconv
03-09-2014, 05:41 PM
I've got an unusual situation that I can't find a solution for, not in the FSM or anywhere else. I actually have the exact same problem on 2 Gen 5 Celica's.

For my 1993 Celica Convertible (automatic, 5S-FE 2.2L), it's a fully restored vehicle, everything operates normally. Cruise control works also, no codes or anything. When the vehicle is at normal operating temperature, cruising at highway speed, the cruise control will properly drop out the lock-up torque converter and downshift from 4th gear down to 3rd gear (although I don't know if the downshift is proper, but dropping out of torque converter lockup is) if the actual car speed drops to 3 MPH below setpoint. All this per the manuals.

But, once the car regains setpoint speed and settles at that speed, the transmission does not go back into torque-converter lockup (nor will it shift from 3rd gear to 4th gear) until 15-30 seconds after the set speed has been reached. The car can even start decending down a hill and yet not upshift and lock the torque converter for a long period of time.

This same condition exists on my son's 1991 Celica ST (4A-FE 1.6L, automatic).

Any other vehicle I have ever driven, if the cruise control required the transmission to drop out of torque converter lock-up, it would re-engage when set speed was reached.

Is this just the nature of 5th Gen Celica's? Given I have 2 different 5th Gens with the same condition, I'm almost thinking it is. Or is there an input to the cruise control module that is out of whack that causes this issue? Just hate for the engines to run so fast for no reason when at the proper set speed.

In both vehicles, this problem condition does not exist with the cruise control not engaged.

muscle_bound89@Live.com
03-14-2014, 02:01 AM
I believe this is common with all of them I had a 5th gen camry that had cruze control and would drop a few mph say when going up a hill.

93celicaconv
03-14-2014, 12:55 PM
I believe this is common with all of them I had a 5th gen camry that had cruze control and would drop a few mph say when going up a hill.

Thanks for the feedback. It's not the drop in speed going up a hill that is the concern at all. It's after the cruise downshifts with a small speed lose, and after the car speed recovers back up to setpoint speed, the transmission remains in the lower gear (engine running very fast) for a long time afterwards, maybe 15-20 seconds, then finally upshifts (engine speed goes back down to normal). Most vehicles I've had, when the car recovers back to set speed, the transmission upshift (engine speed drops) immediately aftewards. I'm just wondernig if there is a reason the transmission won't upshift immediately after the vehicle returns to setpoint speed. I may fiddle with the throttle position sensor position, I've heard that adjustment being off a little may be a cause.