30 May 2012

Back on the road, better than before

Main Screen for the Think Tech Center diagnostic tool
We bought our first Think City EV a year ago at full price and have had no problems with it.  Initially Think did not want to sell me a car since I lived so far from any authorized service.  But I convinced them that I was capable of handling any service on my own.  After the bankruptcy and sale, the new Think North America organization started selling the remaining 150 or so cars at a steep discount.

Replacement Power Conversion Unit
When our second Think City EV arrived, the Power Conversion Unit (PCU) stopped working the first day we drove it.  As I reported earlier, Think's service manager stopped by my house a few days later and diagnosed the problem.  This put to rest any remaining questions about service.  Within days, a replacement PCU arrived with the diagnostic tools needed to reprogram it for my particular car.

Bottom view of the installed PCU showing black low pressure coolant hose.  The main 400 volt cables are orange.

I removed the hood, wipers, air intake, vacuum pump and a few other minor items just so I could look over the job while reading the manuals.  This way I had a good idea of what needed to be done before explaining the project to the shop technician.  Then we had our red Think towed to an independent local shop which has demonstrated interest in EVs, and the real work began.
Think City EV engine compartment after removing the hood, vacuum pump, wipers, air intake, etc.
The shop had to disconnect the 12 volt battery and the 400 volt battery before evacuating the R134a refrigerant from the air conditioner.  Then they removed the condenser to gain access to the PCU.  Next the wiper motor and mechanism had to come out.

Wiper mechanism is off to the side
Numerous other little things such as draining the coolant from the PCU and motor, as well as removing the mounting bracket from the cabin heater had happened before we got to the final bracket in the way of the PCU removal.  The technician told me the manuals did not explicitly mention this bracket, but it was certainly obvious enough.

Soon everything was back together and the Tech Center tool was used to reprogram the VIN and teach the new Vehicle Control Unit to recognize the wireless key fobs, without which the car will not start.

Although I was initially instructed to reprogram the PCU completely, I questioned this since the PCU appeared to be a refurbished unit.  Think agreed, and told me to leave the existing programming if it worked.  This turned out to be a fortunate event, as the programming in the PCU appears to be newer and a noticeable improvement, especially for highway driving. 
Live data read-out from the Battery Management System

More about that in a future post, after I have time to plot the data I took comparing both our new and old Think EVs.  I then returned the PCU and diagnostic tools, but only after getting logs files of the Live Data shown above and below.
Live data read-out from the Power Conversion Unit

The discussion list for the Think City EV over at Yahoo Groups has been very active since the price drop.  There have been some relatively minor problems compared to mine, the worst of which might be a bad 12 volt battery.  Think service quickly provided a document (now posted over at Yahoo Groups) which details replacement procedures for the battery.  (I don't know if this particular 12 volt battery replacement was done at the dealer or by the owner.)  There have also been some loose battery cables.  The speculation is that the factory disconnected the 12 volt batteries when sales slowed after the bankruptcy, and a few were not reconnected tightly before shipping to the buyers.  At these prices, most of us are not complaining very loudly about such things.
Rear torsion bar suspension
I have now seen more of the inner workings of a Think than most drivers ever will.  And on the positive side, I may have one of the first releases of updated power and regeneration curves.  Hopefully these new curves will become available as the new engineering organization in Munich gets up to speed.

There is also a survey going on at the discussion list to find out how many owners might be interested in purchasing the diagnostic tool.  Think is getting ready to place an order with the supplier in England.  I am not the only Think owner who lives far from an authorized service center and wants to own a service tool.  As I understand it, it is possible that the price may be lower if enough units are purchased all at once.  What the survey leaves out is that there might be an annual software maintenance fee for the most up to date versions.


  1. Jim, I'm a new Th!nk City owner in Portland, Oregon. Can you tell me how I might obtain a copy of the factory service manual for the car? I usually maintain our vehicles in my home shop. THANK YOU! Stan.Sittser@pgn.com

  2. Hi Stan

    That article you posted over at the Yahoo discussion group mentioned the Auto Clinic in Portland as the warranty service provider. They should have the manuals.

    I know the manuals are out there, but they are commercial documents so we have been discouraging posting them on the net.

    Say, if you can find contact information for the Auto Clinic that is doing Think service in Portland, let me know and I will post it here.

    Jim McL

  3. Hi Jim. The city hall on the island of Aeroe in Denmark (where I work) has three THINK City cars but none of them are working. The PCU and missing passwords seems to be the problem. We don't know who to contact for help and spare parts. Do you have any suggestions?

    Best regards,
    Thomas Estrup, tes@aeroekommune.dk

  4. Hi Thomas

    I understand that the European Thinks have an earlier version of the PCU (Power Control Unit) than we see in the US. It is somewhat common to need a minor repair of this PCU, after which they remain trouble free.

    I will contact you directly, I know a few people in Norway and Sweden who have done this repair.

    The big Think dealer in Oslo (probably http://www.rohneselmer.no/) can probably help also.

    I am not sure what you mean about passwords, that sounds like an issue with the service tools? I believe they have been updated.

    Jim McL

  5. Hi, where could I get a Think City Power Conversion Unit? Ours is broken, too. I cannot find one! Also the diagnostic tool would be great. I do have quite some HV EV knowledge by the way. We are located in The Netherlands, Europe

  6. Marcus

    If you have the Zebra battery and the Gen 1PCU, try the Think dealer in Oslo mentioned in the previous comment. They can get your PCU repaired.

    If you have the EnerDel battery and the Gen 2 PCU, you should contact Think North America.

  7. if one know how disconnect the "yellow power limit" when it engage wrong, thank you for information !