TCC lockup question
Thread Starter
Instructor
Joined: Jun 2007
Posts: 100
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TCC lockup question
The FSM for my 89 says the torque converter clutch will lock in 3rd gear under certain conditions ( temp, speed etc )when the gear selector is in the drive position. My TCC will not lock in 3rd at all when the gear selector is in the drive position. It does lock as it should in 3rd and OD when the gear selector is in the OD position. I have checked all the wires and the switch in the console and can find nothing wrong. Since it works fine in OD I am of the opinion that the ECM is not sending a signal to the solenoid when the gear selector is in the drive position but I don't know why. One other thing, The FSM says that the switch settings in the console on the gear selector will only affect the speed at which lockup occurs and will not stop lockup from happening at all. Any thoughts would be appreciated.
Race Director
Joined: Aug 2000
Posts: 14,130
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Cruise-In II Veteran
Check your ecm for a aftermarket prom/chip.If there is an ADS or Hypertech chip,or custom chip,it may be the reason.Most delay TC lock up until 4th gear.
If you have the stock chip,then its not very common for it to lock up in 3rd..as you found out.Usually the dash will light up first telling you to upshift into OD or 4th.Is that what your seeing?
If you have the stock chip,then its not very common for it to lock up in 3rd..as you found out.Usually the dash will light up first telling you to upshift into OD or 4th.Is that what your seeing?
Thread Starter
Instructor
Joined: Jun 2007
Posts: 100
Likes: 0
Stock chip on 700R4 transmission on 1989 Corvette. I do not have an upshift light on dash that I am aware of. Only reason I asked is because the FSM says flat out it should lock when the gear selector is in drive and it doesn't and I wanted to figure out why.
