This is the first Winter Season I'm going through with my Accord, and I noticed that when the temperature gets to about 35 outside my torque converter won't lock up at highway speeds even after driving the car non-stop down the highway for 25miles (my morning commute). Now if I pull off the highway and stop (not shutting off the car), and then get back on the highway the converter will lock.
Is this the normal warm up sequence for the TCU? The car shifts smooth hot or cold so I don't think anything is wrong with the Transmission.

 

replace your thermostat. TQ converter will not lock up if the ECU does not see car at operating temp

 

Also check the torque converter lock-up clutch. My car (1991 Accord, automatic transmission) has one, but I can't tell when it engages.

 

I had the same problem with my '94 accord when the tstat stuck in the open position. I was still getting heat but had the exact same problem as he did. Once I replaced the t-stat the problem dissapeared and my gas milage went up 2 mpg from 23 city to 25 city and back up from 32 highway to 34..

The reason I doubt it is the TQ clutch is he stated it just started happening when it got cooler outside...

 

Yeu, my car runs slightly cooler than normal (normal for my car is 180 degrees; it runs usually 160 degrees). I run 5W-30 TropArtic synthetic blend oil coupled with Prestone Cold Start fuel treatment. I am currently trying to find a guage that reads both the intake charge temperature and the cylinder head temperature.

 

Thanks Yeu , More than likely it's the original T-stat and @ 152k it's probably time for a replace. I'm on my way to the parts store.

 

While youre there, get a 160-degree thermostat. It will help the car run slightly cooler than normal, which will offer a slight increase in performance.

 

Hi, I have a 1992 Accord. I am now experiencing lockup issues. The car jumps in and out of lockup at speeds above 50 when cruising with neutral acceleration. When I accelerate it locks up. It jumps around 300 RPM when it jumps out and its only for a moment. I have looked online for a solution. I have found several theories but no definite cause or solution. Any ideas?

 

Same issues, have you ever found a solution?