Questions and Answers

Toyota 4runner Loses OD Q. Hi Vincent, I have a 1990 Toyota 4runner, 6 cylinder, 2WD, fuel injection, automatic transmission, 132,000 miles, P/S, A/C and cruise control. From the last six months I have a problem with the overdrive. When I start the car, (in cool) no matter a what speed I drive, the transmission does not change to the overdrive.

Then I have noticed that when the car reach the normal temperature (temperature dial is set around the mid on the scale) the car start changing to the overdrive. At this point the car run as a new. No problem to complain.

Now, is for example I drive in the expressway, and the day is not too hot, the temperature goes down a little bit, and I overdrive. I have asked some mechanics, some of then says the transmission must be repaired, other says it's normal. I'm not sure to spend a lot of money in repairing the transmission if it is okay.

There is another interesting point, I have noticed this situation after a mechanic made a cleaning in the choke, adjust the choke wire, the opening, etc. He made those adjustments because the car was running too high at idle. I don't know, may be is just coincidence, you know about this. I appreciate your comments.

Thank you,
William

A. There was a bulletin out on a problem such as you describe. It is:

NO.: TM92-002 (REVISED)

Date: April 10, 1992

Model: VN

Intermittent Engagement Of Overdrive

Condition:
Intermittent loss of overdrive when the engine is at a normal operating temperature and at speeds above 45 mph.

Cause:
High resistance in the E-17 splice (THW circuit).

Correction:
Clean the E-17 splice and then solder. The E-17 splice is located behind the power steering reservoir (see illustration).

Note: The E-17 splice is located behind the power steering pump. In most cases it can be reached without removing components.

It's possible when the work was done this splice was disturbed.