The S2000 Scan Tool for Prius Series 1
I have reproduced Kevin’s post in here as it answers the issues with removing the error codes in the battery computer in detail. At the battery clinic we strip the battery and balance the cells. They are now hard to come by as the series 1 battery is no longer used. We can rebuilt the cells in a new tube.
It is now known that the battery computer is damaged by voltage spikes caused by faulty tubes. This can be physically repaired. It is important that the repaired computer should be used with the faulty battery or it will be damaged again.
This message from Kevin in the Yahoo Mk1 Prius Forum
I own a Prius Mk1 and have done a considerable amount of research on the scanning of this car. Despite the fact that it has a standard 16 pin OBD connector, it is one of the first few cars to use the 16 pin connector BEFORE it was adopted as any sort of standard. The standard of “OBD-11″ only applied as compulsory in the USA from 1995 anyway, and car manufacturers only had to comply with OBD-11 if they wished to sell there cars in the USA from 1995. Toyota did not wish to sell their Prius Mk1 outside of Japan and the 1995 OBD-11 protocols around at the time did not suit their needs, as they were inadequate for this car. I can reveal that the car is using “Toyota M- OBD”, Toyota multiplex onboard diagnostics according to people who specalise in Toyota OBD. In the 16 pin connector (correctly known as the J1962 socket) the pins are as follows :
pin 16 = battery
pin 4 = ground
pin 13= test pin
pins 6,7,9,14 are communication pins
The Prius Mk1 uses a ECU for each of, the engine, the ABS, the airbag, the Hybrid running gear and finally the Hybrid battery. Toyota themselves use a “Techmaster scantool” with an “S2000″ cartridge adaptor, with software that they wrote themselves just for this car, only available to Toyota maindealers in Japan. The software itself uses “keyword protocols”, (that’s code words to you and me), using ALDL speeds of communication ( Assembly Line Diagnostic Link), now known communally as OBD-1 speeds of communication, first used commonly by General motors in the mid 1980′s. The problem with getting a scan tool to handle the Prius Mk1 is, that the scan tool needs to handle “Toyota M-OBD” keyword protacols, It also deeds to have a “J1962 connector” with the correct pin configuration.
All OBD-1 and OBD-11 dedicated scantools will not work on this car !!!!!! I know, I have tried several of them that are on the market. Some of them costing several thousand of pounds. There are some of the more expensive ones that do the Prius MK11 (which is OBD-11 compliant using more common keyword protocols) and Prius Mk111&1V using OBD-11 “CAN” (continuous area network protocols). So “what’s to do then”?
The only “After market” scan tools that are known to read the OBD’s of the Prius Mk1 cars are the “Carman” scan tools range made by Nextech. The Carman A200( now discontinued) , the carman scan lite and the Carman VG. The scantools also have to have the September 2007 software update to get the best results as well. The carman scan lite is £1500 ($3000) retail. I own a Carman scan lite, and the scan tool Is “brilliant”, as it leaves no stone unturned, you can get all the information from the car that you need on any aspect. All 20 of Prs of modules in the Hybrid battery are shown including voltages, Ohms, temp of each Pr. Also the overall max and min voltages and temperatures of the monitoring system and exact % of overall charge as well as information on every sensor on the whole car. it will give you all the trouble codes on each of the ECU’s and enable you to reset them as well.
The only down side to the Carman scan tools are that they do not ” flash” the ECU’s, that is to say that, as of yet, the software dose not turn the ” balance charge request” from “OFF” to “ON” and back again, even though you can see it on the scan.
One of the problems with these cars is that the cells in the Hybrid battery are an early type of “high capacity” NM-Hi, and over time they may suffer from the ” battery memory affect”, problem similar to NI-CAD cells, and they discharge more rapidly if left unused for any length of time as well.
Toyota thought to overcome this problem by using their scantool to do the “balance charge request” maneuver ,by using the cars own charging system,( a full overall/across the board 110% charge) to rejuvenate the whole Battery in one go, if this failed they would fit a free RE-CON battery instead, all though this was rare.
So sadly, we “outside of Japan” owners can only strip the Hybrid Battery down ( be careful they are 315 DC volts when fully charged, from first to last terminal, according to my carman scantool info, electricians tools and gloves required). You then have to rejuvenate each module, one at a time, replacing any failed ones, and finally rebuild the battery again using as evenly as balanced pairs as you can. The Carman scan lite can help you monitor this Process but ” If only” it cannot do the balance charge maneuver as of yet as I have said. Some cars go on and on, without problems ( 100,000 miles +) with the battery, some have stripped the battery down and replaced a ” too good” a module, to achieve a balance.
So until hopefully, Carman sort out a “balance charge maneuver” setting on their scan tool, in one of their future software updates, we will still have to do this by hand. Other wise the carman scan tools covers everything else and is unique.
