Picking up where we left off last month as promised, we are going to take a closer look at the valve body and the operation of the timing solenoid (see Figure 1). But before we get into it, there are a couple of things to be aware of.
Last month we explained the variety of operating modes the different manufacturers use to control AW55-50 units in their vehicles. Knowing the modes and when they are activated is the first step in making an accurate diagnosis. A symptom reported by a customer may be normal, intended operation for one brand of vehicle and a legitimate problem in another. As part of your diagnosis, you also should be aware that every manufacturer has at least one transmission-control-module (TCM) reflash or replacement bulletin to address various transmission concerns.
We had a similar problem come to the shop in a 2000 Toyota Tacoma. The customer’s complaint went like this: “When I have the cruise control on and I turn on my left turn signal the cruise control turns off, but not when I turn on my right turn signal. I also notice that the transmission drops out of overdrive when I turn on my left turn signal but not when I turn on my right turn signal.”
At this point most engineers were assuming that the stator-cap material needed to be upgraded, and that is where they focused their research. However, we all know what assuming does.
Since consumers have the luxury of being more finicky about their purchases, our industry needs to fight harder for every sale and be sure that when we make one it is profitable and creates or continues a long-term relationship. In times like these we want to offer the consumer the whole package as it relates to the entire experience of doing business with us; the “END ALL TO BEAT ALL” of the industry. It’s the “WOW!” factor, the “I CAN’T BELIEVE I’M IN AN AUTO REPAIR SHOP!” factor.
The automatic transmission equipped with a torque converter has been the mainstay of conventional drivelines since World War II. A great deal of research, improved designs and advanced transmission technology have brought us excellent five-, six- and seven-speed automatics that perform extremely well. Manual transmissions are still more efficient from the fuel-economy standpoint but depend on the driver’s skill and ability to drive in a fuel-efficient manner. The EPA does not like manual transmissions because they shift at closed throttle. Automatics shift at open throttle and make control of emission levels much easier.
This time, however, he was trying to decide on whether to retire this car and move on to another. He has two vehicles already running well, and this one is a spare. Clean as a pin for a ’91 and still well under 100,000 on the clock. Ideally, I’d like to have been able to tell him what the cost would be to get the car running without spending a lot of diagnostic time trying to find out why it quit. I mean, it’s a 3.3 Chrysler; how hard can it be?