In a previous post I rated this as the #3 most serious problem with the Think City. It can put you in an awfully awkward situation, but won’t kill your car completely, as long as it doesn’t cause you to get into a wreck.
The usual symptom of this species of fault goes something like this:
You get in the car, make sure the blower is off, put in the key, turn the car on, put on your seatbelt, foot on the brake, shift into reverse, turn around to make sure you don’t hit anything, let up on the brake to ease out of your parking space…
But you don’t go anywhere.
Is the car on? Maybe you didn’t turn the key all the way to start… No, that’s fine– you can hear the hum of the water pumps and you see the green car icon on the center console is on.
Oh, wait. The indicator on the center console says you’re in Neutral– you must have pulled the gearshift lever two notches back instead of just one, right? You bump the lever forward one notch, but now you’re in Park. It won’t go any further forward, so yes, you must be in Park. Very carefully this time, you pull the gearshift lever back exactly one notch… but the indicator skips over Reverse and goes straight to Neutral. You move the lever one notch further back: still Neutral. Back one more: Now it’s in Drive just like it should be. Back one more. Still in Drive? It should be in Economy. What is going on here?! And how am I going to get out of this parking space?!
Let’s tackle the second question first: How do you back up when you don’t have Reverse?
- You can keep moving the gearshift lever forward and back over and over again, hoping for Reverse to finally be indicated, and sometimes this works. Please just don’t slam the lever all the way forward or back or twist it or otherwise abuse it. There is no magic method for making Reverse appear, but there are methods for damaging the gearshift assembly even further. This problem can start out as a very intermittent event– when I first started diagnosing these I could often not replicate the customers’ complaints. But it can develop into a situation in which you will virtually never be able to get into Reverse.
- You can move your car by human power. If you choose this method do not, Do Not, DO NOT leave the gearshift lever in the position that is normally Reverse. At any instant the indicator could switch from Neutral to Reverse while you are standing outside your car, and the car will take off backward with no one in the driver’s seat. Instead you can put the gearshift lever in the Neutral position (which will also indicate Neutral), and then get out an push your car around. There is virtually no chance that your car will indicate any other gear than Neutral while the gearshift lever is in the Neutral position. If you are still nervous about this, you can turn the key off with the gearshift lever in the Neutral position so there’s 0% chance of it being powered without someone in the driver’s seat. You won’t be able to take the key out of the “ignition” while in Neutral, and that’s fine because you need the key to remain in so you can turn the steering wheel as you’re pushing your car backward. Once you get far enough back you can (restart if necessary and) shift into Drive, and you’re on your way.
Now, why is this happening? Before I explain what’s going wrong here, allow me to provide a brief description of how the gearshift assembly does its thing.
There is a cable that goes from the gearshift assembly to the transaxle, aka gearbox. Even though the gearshift lever has 5 positions, the cable only has 2 functional positions: Park and everything else. When the gearshift lever is in Park, the cable actuates a parking pawl within the gearbox that prevents a reduction gear from rotating more that a small fraction of a revolution. (This is why, when your car is in Park, you can still push it forward or back an inch or two. This is also why, when a car is in Park and lifted so both front wheels are off the ground, you can spin either wheel and the wheel on the opposite side will spin in the opposite direction due to the action of the differential.) So the parking pawl is either engaged (in Park) or disengaged (anything other than Park), and that is the only reason for the connection between the gearshift assembly and the transaxle. So really it doesn’t have anything to do with the problem we’re talking about here.
The car (or the Vehicle Control Unit and the Power Conversion Unit) knows what gear you want based on three 5-Volt signals that are controlled by three microswitches on the left side the gearshift assembly. As the gearshift lever moves forward and back, a cam attached to the lever causes the switches to open and close, respectively allowing signals to either stay at 5 Volts or be pulled to ground.
Two additional microswitches on the right side of the gearshift assembly function to indicate whether the gearshift lever is in Park (redundant to the combined signal from the other 3 switches) and to indicate if the thumb-actuated release button is being pressed. The output from these switches is used to keep you from pulling the key out of the “ignition” unless you are in Park, and to sound an annoying tone if you press the release button while the driver’s door is open. The important thing to know about these switches is that if the Park switch indicates that the gearshift lever is in the Park position while the other 3 microswitches indicate anything other than the correct code for Park, the car will instantly shut down and flash the Neutral indicator. But that’s a separate problem. The two microswitches on the right side of the gearshift assembly really don’t have anything to do with the problem that we’re talking about here.
So there are two possible causes of the fault described above, and they are both in the 3-microswitch/cam system:
- The cam may be misaligned to the microswitches. Either there was a flaw in design or the plastic cam becomes slightly warped over time and bends to the left. The fix for this is easy: Install two fender washers behind the plastic bracket that holds the microswitches; this offsets the microswitches by about 2 or 3 mm. (A fender washer is simply a washer that has a small inside diameter (hole) and a large outside diameter.) Think North America even issued a Technical Service Bulletin regarding this issue.
- One of the microswitches is causing an open circuit so a signal that should be grounded is still at 5 Volts. It is almost always the right-most microswitch which happens to be the one that is most frequently actuated by the cam.
Now that you have an idea of what’s going wrong with your car you can take it to your local Think service technician for repair. Or if you’re a bit more thrifty, and if you agree to not hold me liable for any advice that I provide, you can try to fix it yourself.
(I’m still working on the instructions for how to do this repair.)