OBD II on Jap import MRS

Anonymous · August 4, 2004, 19:44

I have a specific question regarding reading of OBD II on Japanese import MR-S. I have already used the forum search.

I have an interface cable using the ELM323 chip from http://www.skpang.co.uk with the latest v2.0 of the ELM323 chip.

I find that I cannot read the OBD II port. I keep receiving "bus init error" messages from the interface.

I have read the previous information, some of which eludes to the missing signal ground pin 5 on the Jap imports. I checked with skpang and they confirmed that their interface does not use pin 5 anyway: It uses the chassis ground pin 4.

Also, on other forums some people have said that some OBD readers will respond to only an 0x08 byte and not the 0x94 byte like the ISO standard stipulates. I have checked on this, and the v2.0 of the ELM323 chip responds to both, so this is not the problem.

I also read that Torque Developments might be able to read the Jap imports OBD II. I sent them an email but they replied stating that they do not provide technical support.

Has anybody on this forum managed to read OBD II from a Jap import MR-S? If so, how did you do it.

Obviously, from the OBD II pinout I have made the assumption that the interface is of the ISO flavour (K line only interface), and also the possible presence of a CAN interface.

(I do not need to read anything particular at this time. I do want the capability to be able to so that when I need to I am able.)

Anonymous · August 4, 2004, 19:50

First off welcome to the club. s:D

s:D

I have a Jap MRS and with someone that has a reader, we shorted together the 2pins to put an earth to pin5 as all OBD pin out diagrams i have seen require this. It didn't work.

I recall someone on here that posted a link to a reader that does read our OBD codes but i'm afraid i can't remember who or where it was.

Try searching a bit more on here as it is definatly here somewhere, hopefully someone will chip in to help you (and me) soon.

Anonymous · August 6, 2004, 22:01

i've an mrs too, so id also appreciate some info on this too

mph · August 7, 2004, 01:25

m http://www.mr2roc.org/forum/viewtopic.php?t=1537 m

Anonymous · August 7, 2004, 18:51

Thanks for those links.

I've checked out the prices by sending an email. The AD200 is £2000 and the AD300 is £3000. Apparently, the only differences are that the AD300 has a scope function.

However, still no specific info on why J-spec gives problems with OBD II and UK do not.

My original wish is to be able to read my own OBD codes so that I can save money from scans, but also if the MIL light comes on one can immediately read the codes and differentiate between "crank angle sensor bad" and "o2 sensor out of range": The former requiring a tow and the latter could be driven for a while until the sensor can be fixed.

Any specific info on how to read (at home, with a sensibly priced bit of kit) J-spec MR-S OBD would be appreciated.

Anonymous · August 12, 2004, 20:30

I have a question regarding the AD300 kit to people who have used it on J-spec MR-S: When it successfully accesses a J-spec MR-S, does it do so in the context of ISO, or does it use CAN?

The reason I ask is that the OBD connector looks like it could support CAN.

Also, if the AD300 reads ISO from a J-spec, then that would point me (and others) in the correct direction:

e.g. If it is ISO, then is it just a grounding problem (pin 5) and / or a software problem (J-spec may use a different ISO OBD sequence?). If the AD300 does NOT talk to the MR-S using ISO then ...

Anonymous · August 12, 2004, 23:06

I admire your commitment to this.

I don't know of anyone though on this site that has gone as far as i did, which wasn't much s:oops: :oops: s:oops: , by connecting an ODBII reader after shorting pins 4 & 5 together after reading things like this m http://www.obdii.com/connector.html#which%20cars m on the std of OBDII connectors. J Spec are definately missing pin5 which according to all the std's is a must.
J1850 VPW--The connector should have metallic contacts in pins 2, 4, 5, and 16, but not 10.
ISO 9141-2--The connector should have metallic contacts in pins 4, 5, 7, 15, and 16.
J1850 PWM--The connector should have metallic contacts in pins 2, 4, 5, 10, and 16.

The reader did seem at first like it was communicating but then it just threw up an error.Time was against us so we stopped there.That's the best i can do, ISO and CAN are like a foreign language to me i'm afraid.

I sadly even joined a OBDII chat forum, but no-one replied to my question....maybe i was the only member s:roll: :roll: s:roll:

Good luck

DAZ400 · August 16, 2004, 12:08

Hi Mr Mark the elm chip will not work with j spec because they have changed the timing deliberatly so we can't use the ISO tools, it is a shame it nearly works but not quite I think the ISO is about 10khz and the the j spec about 9.7khz I can't really remember to be honest but that is why it wont work.

Regards the CAN bus yes it is on both cars but not shaw it will give you the same info out, it is proberbly used more for manufacture and setup like when clutch is changed and car has to be reprogrammed to learn new clutch.

Hi Ian what you been upto email me.

Anonymous · August 25, 2004, 21:20

Thanks for that info. The 10khz to 9.7khz drop is particularly interesting. Where did you obtain this info?

The following thought occurred to me:

The elm chip uses a 3.58MHz (NTSC colour) crystal. I assume that this provides timing for the OBD side of the chip.

Apparently the crystal also provides timing for the RS232 side of the elm chip, with a nominal 9600 baud at 8 data bits, no parity and 1 stop bit when using this crystal.

If the crystal freq could be dropped so that the OBD might just be in spec and the R232 side a little too low, it might just work. A 3.5 Mhz crystal would generate about 9.7khz (assuming it affects the OBD timing on the elm chip) and drop the RS223 side to about 9300.

I'll see if I can get some more info upon the chip and post it.

DAZ400 · August 26, 2004, 18:28

I can't remember where I see this information but it did make sense when I did some testing with Ian on his MR-S. It is only marginally different and maybe it is possable to change the frequency to bring it back in line, and their is some error tolerence on the RS232 timing but weather this is enougth I don't know.

Probably best to mail the elm guys and ask them they ought to have all the answers.

Anonymous · August 26, 2004, 21:09

I've now checked with w www.skpang.co.uk w where I got the ELM 323 cable and their help system from w www.scantool.net w .

From what I am told the crystal affects BOTH sides: The RS 232 speed and the OBD speed.

Anonymous · August 26, 2004, 21:32

s:? :? s:? So, for the other people on this site who's first language is English s:D

s:D , are you any closer to understanding what the problem is and how to sort it? Thanks

Anonymous · August 26, 2004, 23:15

Slight topic drift... s:)

s:)

I have a J-spec MR-S, and I've just had a 50,000 intermediate service recently. (Although me cars only done 30,000) I wanted to see an error report to see if there was anything needed doing.

Toyota gave me a basic report and said that they had sent my fault codes off to Japan because their machine could not read them.

Just a few questions thats been bugging me...

1) Do Toyota normally include a OBD II Diagnostic report with such a service for UK spec cars?

2) Are they fobbing me off, because as far as Im understanding so far, UK machines have a different connection so couldn't even bring up Japanese codes.

Approximately after 9 calls (five times more them promising to call me back) and two visits and lots of buck swapping, I still have never had any straight answers off toyota, let alone any fault code info from the land of the rising sun... s:x :x s:x

Anonymous · August 27, 2004, 19:42

mr-s_turbo wrote:

QuoteSo, for the other people on this site who's first language is English , are you any closer to understanding what the problem is and how to sort it? Thanks

Not sure. So far DAZ400 has suggested that rather than using the normal 10.4kHz OBD data transfer, the J-specs use 9.7kHz data transfer. This would mean that all normal scanners have no chance of reading it.

What I was suggesting was in the interface box between the PC and car, lowering the frequency by altering the crystal. This might bring the OBD data rate closer to what is required for J-spec. However, it would also alter the RS232 speed that I use to communicate with the OBD interface box via hyperterminal from my PC to a non-standard speed, something which probably would not be allowed (RS232 is always standard speeds - 9600, 4800 etc).

I will investigate this.

However, no guarantees that this would even work.

I did have another thought: I have read that the ECUs in all MR-S are identical. So, how would it know if it was a J-spec or european? perhaps the ECU determines the type of car it is in from some of the connected sensors - EU cars have 3 o2 sensors, J-spec have 2 etc.

I have tried everywhere I can think of to attempt to get definitive information about the J-spec OBD, but have come to dead-ends.

Anonymous · November 27, 2005, 08:24

I know this is an old thread... I am one of the suckers that bought an ISO scanner, soldered pins 4 & 5... got the power lights and a few other readings... but can't get the fault codes...

My MR2 is an Australian one (2002 - Nov.. I think same as a 2003 model)... just curious as to whether the OBD is also this J-Spec non-sense!

I have the following pin layouts... can someone with a J-Spec MR2 confirm whether they have the same as mine?

4,6,7
9,13,14,16

It almost seems like its a CAN... but don't want to blow another $200 finding out...

Quote from: "mr_mark"mr-s_turbo wrote:
QuoteSo, for the other people on this site who's first language is English , are you any closer to understanding what the problem is and how to sort it? Thanks

Not sure. So far DAZ400 has suggested that rather than using the normal 10.4kHz OBD data transfer, the J-specs use 9.7kHz data transfer. This would mean that all normal scanners have no chance of reading it.

What I was suggesting was in the interface box between the PC and car, lowering the frequency by altering the crystal. This might bring the OBD data rate closer to what is required for J-spec. However, it would also alter the RS232 speed that I use to communicate with the OBD interface box via hyperterminal from my PC to a non-standard speed, something which probably would not be allowed (RS232 is always standard speeds - 9600, 4800 etc).

I will investigate this.

However, no guarantees that this would even work.

I did have another thought: I have read that the ECUs in all MR-S are identical. So, how would it know if it was a J-spec or european? perhaps the ECU determines the type of car it is in from some of the connected sensors - EU cars have 3 o2 sensors, J-spec have 2 etc.

I have tried everywhere I can think of to attempt to get definitive information about the J-spec OBD, but have come to dead-ends.

Jap GT300 · November 28, 2005, 16:13

Ring round some of the Toyota Garages. A lot of them now have the Japanese card to read the OBD port like Jemca, Sidcup.

TTE were able to read one of my mr-s even with just their german card installed although they couldn't clear any codes.

spit · November 29, 2005, 18:36

The hand-held diagnostic kit that the guys at Camcoat (Camco) have will read J-Spec and clear codes too. I'll have a word with them & see if I can find out whats special about it. s:wink: :wink: s:wink: