My automatic transmission isn’t shifting right. It will upshift correctly the first time, but then won’t downshift when I slow down or come to a stop. It also doesn’t downshift when pulling up a hill. I can manually shift it, but it still doesn’t feel right. It’s also making a noise when I shift it into D(rive) or R(everse).
What is the vehicle? 1985 Toyota 4Runner 4wd
How many miles? 260K+
Is the fluid level correct? Yes, but it may be a little dirty.
Is the check engine light on? Yes
Diagnosis by phone: This could be many things. The solenoids could all be bad. With this many miles, it could need a complete rebuild. The first thing I would do is to see if the check engine light code could shed some light on this.
Inspection/diagnosis: I pulled the codes and there were three of them. One was a TPS code, the second was a Signal Wire code, and the third was a Knock Sensor code. At this point I’m not convinced that any of these have a direct correlation with the shifting issue. I decide to consult with one of my technician peers and ask his opinion. His comment is “replace the TPS, that has bit me more than once.” Wow, that was a quick answer.
Repair: I replaced the TPS and now the TPS code goes away and it starts to shift better. On the following test drives I find that it still seems that it isn’t shifting like it should, but it is actually shifting on it’s own. It’s still making a noise when it is shifted into drive or reverse most of the time.
See the next blog “What’s that bang?!” for further diagnosis of this automatic transmission.