It has been a long time since I posted anything on this issue, but today I had some time to troubleshoot this. I found Chapter "G.7.5 Programming new EEC-V" in the Think Service Manual. It seems pretty simple to exchange to a new VCU/EEC-V, so I decided to try the VCU from my working Think in my Think with the dead CAN bus. The reason I wanted to test this is that with the old VCU the CAN bus didn't measure 60 Ohm.
With the working VCU in place the CAN Bus was still dead when I used PEAK Viewer and had the ignition key turned to run. The symptoms on the dashboard is just the same. The wrench lamp is still on and the PATS key is still blinking quickly. I even tried to program the VCU like it was described in the service manual, but since the CAN bus is dead I guess this would not work anyway.
I also tried the VCU from the nonworking car in the working car. The working car did now also show the quickly blinking PATS key light. My guess was that if the VCU was OK I would be able to program it by using my two keys one at the time, but this did not work. I wonder why? Have anyone been programing the VCU and know that this works? Would you please explain in details how you did it if it is not exactly like the procedure below:

disconnect 12v battery
remove old VCU, and connect new VCU
connect 12v battery
cycle one key to run and remove (out of the car)
cycle the other key to run

I must also add that the CAN bus on the working car did work with the VCU from the nonworking car, so it seems the problem with the CAN bus is not related to the VCU. I'm at least happy that I didn't just buy a new VCU :-)

Er det noen som har bygget om 2008-2012 Think City fra 2 seter til 4 seter?
Er det noen som sitter på papirene som er nødvendig overfor biltilsynet for å registrere bilen med en høyere totalvekt?
Hva var forskjellen på 2 seter og 4 seter versjonen?

Mvh
Terje

Thanks for informative picture Orla, I probably wouldn't have found the SRS ECU without it 

When I measured 60 Ohm between pin 14 and 6 in the ODB2 connector, the widest of the tree contacts on the VCU was disconnected. When this connector (on the VCU) was connected again the resistance fell to about 48 Ohm (When everything I know about is connected).
When I connected the PCAN_USB tool and looked with PCAN Viewer at 500kB I could not see any messages on the bus. When I at the same time start the Comm Tool also at 500kB, select a diagnostic file and click Get Data --> I see in the PCAN Viewer the messages that the Comm Tool sends on the CAN bus, but no answers.
Would someone be able to test if the CAN bus will work without the widest contact of the VCU connected? I believe it will work, but the reason I ask is that I see the wiring connections markes "wakeup" in the wiring diagrams. Could it be the VCU that wakes up the other devises on the CAN bus, so that the CAN bus will be dead without a working VCU?

Regards
Terje

I have been disconnecting one by one of the devices on the CAN bus and measured the resistance on the bus. I thought I had found the source of the problems when I disconnected the VCU and the resistance on the bus increased from 85 Ohm to about 120 Ohm with the PCU disconnected. I connected the PCU and did a control measure on the ODB2 connector, which by now showed 60 Ohm. I thought I would get traffic on the bus when I powered up without the VCU, but that was not the case.
Does anybody know if this is normal? Do I need to have the VCU connected to wake up the systems?

By the way, I can't find the TPMS, SRS airbag ECU and the RAC (mindbox). Could someone indicate the location of these devices?

As I understand the wiring diagams the PAS, ABS and BMS is all connected on the PCU side when the multi connector on the PCU is disconnected? I measured 120 Ohm on the PCU side, so I have not investigated these systems.

Are there anyone that has some tips on further troubleshooting?

Regards
Terje

Thanks for great info regarding the multi connector!
I think we start to home in on the real issue. The PCU side of the CAN bus had 120 Ohm, but the cable side had only 84 Ohm. When I connect the multi connector to the PCU and measure from the ODB2 connector it shows 49 Ohm.
I just found the wiring diagrams for Think gen2 on a ftp server link found in the Yahoo USA group. I will start the troubleshooting tomorrow if I get time. Thanks for helping me in the right direction!

Regards
Terje

Thanks for your answer!

Do you know which of the pins in the multi connector that are for the CAN bus? I can't find any documentation on that connector.

The documentation is a bit confusing as well since it seems to be for gen1 since it is a bit different than in my car.

I guess I could just measure the CAN bus in the ODB2 connector in the main fuse box? It's to late to do it today, so I have to look into it tomorrow.

Regards
Terje

Hi,
I have for some time tried to breathe new life in my 2010 Think City Gen2 with lithium batteries. I bought it right after a workshop had found out that it needed a new PCU. I thought that I might figure out what was wrong with the PCU, and bring it back to life. So far I have learned a lot, but not yet found the source of the problems.
Maybe someone could give me some clues where to look next?
The history is like this:
The car started to need several tries on the key to finally start. In the end it didn't start after 100 full sycles of the key (This is what the old owner tells me).
The workshop investigates and tells the owner he needs to buy a new PCU for NOK 37.000.
The owner sells the car to me.
I use about a month to get hold of the Think diagnostic tools, but I'm not able to get communication with the PCU/ECU.
I pick apart the PCU and look for broken fuses. I onl find one broken fuse, and that is the FU7 which seems to belong to the Air Condition which my car does not have. That is strange, but I change it anyway, and put togehter the PCU and does a new test with it in the car. The symptoms are all the same: drive lock on (blinking red key on top center dashboard), red wrench indicator and no green car symbol.
I pick the PCU apart again and take out the processor board, since this is where the multi connector for communication between the car and the PCU sits.
I look for fuses on the circuit board (other than the obvious big red one which was not broken) and finds two small fuses near the multi connector. Both of them was OK. I try to do some diagnostics on the board without having been able to retrieve test procedures for the inside components of the PCU. This was not easy for me, but I find that only a small part of the processor circuit board, near the 12VDC power inlet, has power over the different small surface mounter capacitors (while the card is out of the PCU). I have also ohm'ed the +12 connection to be good all the way to the processor card, so I know that this board should get 12VDC.
I decide to buy a new processor board.
With the new processor board installed I still have the same symptoms!
Since I didn't get communication with the PCU/ECU even after changing the processor board, I decided to look into the PCAN tool to see what I could find out with that one.
The same thing happens again. The CAN bus seems dead. When I use the Comm Tool together with the PCAN Viewer I can see that I send CAN commands from the Comm Tool, but there are no answers from the devices which should communicate on the CAN bus. I can not see any traffic on the bus by using the PCAN viewer either.
I have a good indication that the diagnostic tools work, since the led(s) in both the Omnitech device and the PCAN-usb is lit and flashing. The drivers is reported to be working in the device manager.
I currently do not have the correct connector to connect to the connector underneath the fusebox in the car, so I do not know if this tool could give me any clues to what is wrong?
If someone knows what could bring down the CAN bus, I guess we would be on to something.
Any good tips on where to start is appreciated.

Er det noen som har noe dypere dokumentasjon på innholdet i PCUen?

Jeg bor på Nøtterøy ved Tønsberg.

Hei,

jeg har en Think fra 2010 med Gen 2 PCU og Lithium batteri. Bilen har ikke gått i mitt eie, men jeg jobber med å få den igang igjen. I kveld tok jeg ut PCU'en i håp om at jeg skulle finne noen feil der som kunne forklare symptomene jeg har, men jeg er ikke så sikker på at jeg har funnet feilen selv om sikring 7 ser ut til å ha gått. Forstår det slik at sikring 7 har med varmekolben eller AC å gjøre. Regner derfor ikke med at det er grunnen til at min bil ikke kan kjøres? Hvordan symptomer får man ved defekt sikring nr 7?

Jeg kan forklare symptomene jeg har som kanskje kan gi noe ledetråder for de som er kyndige på dette:
- Skiftenøkkelsymbolet på dashbordet lyser
- Startsperren blinker kjapt når tenningen settes på og startsekvensen er ferdig. Jeg får dessuten ikke kodet nøklene siden Think TechCenter får error når jeg forsøker å kode nøklene (de to første punktene er grønne, men så kommer error).
- Alt av lys og instrumenter ser ut til å virke, men..
- Jeg får ikke kontakt med noen ECU'er med Think TechCenter. Får feilmeldingen "Can databuffer empty", og får derfor ikke lest ut feilkoder.
- Bilen lader normalt
- Alle sikringene er hele i sikringsboksen.
- Litt sløvt, men fant ut i dag at det ikke var glykol på kjølesløyfen:-) Kan dette være en grunn til at ikke ECUer får spenning?

Håper noen har noen ledetråder som kan få meg videre i denne saken.