Re:JB74 OBD2 connection

Hello all,

I am currently stationed in Sarawak (Borneo) and have just picked up a 2020 Suzuki Jimny JB74.

I'm no stranger to operating SJ413's in the tropics and have always installed an Engine Watchdog to keep an eye on the engine/gearbox temperature.

The new Jimny (JB74) has an OBD2 port, so I was looking forward to setting up a monitoring system via the OBD2 with pre set alarms for temperature, voltage etc to give me fair warning that a problem was brewing before it got me into trouble in the sticks.

On youtube I found this gentleman who had installed an Autool X60 into his JB74, which fit the bill perfectly.


So I got one for mine, but no joy, doesn't work, just says it cannot connect. I wonder why it works in his, but not in mine?

I have since tried a Bluetooth OBD2 connector and apps like Torque pro, same problem, cannot connect.

The only success I have had is with Anton Malykh's SZ Viewer A1 app, which does connect, but I haven't figured out a way to use this for to create temperature and voltage alarms.

Does anyone have any idea why monci85 (italian gentleman on youtube) has an OBD2 interface which appears to happily talk to OBD2 compatible devices, yet my JB74 won't?

I have an autool x50 that works well in my 2011 gen3. Could it be a market difference? I know that Australia is different to Europe and South Africa is different again for things like in car entertainment, might be worth asking the dealership if it's a potential difference. Though I did think obd2 was universal.

When Suzuki visited my home and my new Gen4 Jimny, they saw I had a AUTool X50+ still in the box, their response was, don't! There is a wiring anomaly that makes it incompatible with the new Suzukis. It's still in the box!

This topic better explains it: www.bigjimny.com/index.php/forum/7-jimny...eader-display#192845

Although I don't have a Gen4 I have just spent a fair bit of time looking at OBD2, dongles and readers.

My Gen3 doesn't have CAN, just J1962, but newer Gen4s might have CAN. Some models might have both, so the Gen4 you saw using the autool might have had both and your model might only have CAN.

SZ Viewer A1 works on my Gen3, using J1962 (K-line), but this program also supports CAN, so perhaps it is working due to how the OBD2 is wired on your Jimny and the autool doesn't work as it doesn't support CAN? The best resource is the SZ Viewer page, see the wiring of the connector to work out if you have J1962, CAN or both.

malykh.com/soft/sz-viewer/

I think this program tells you which protocol it is using, perhaps this would give you a clue?

I run Torque Pro on my Gen3 and there are a number of settings to select the protocol under the advanced menu, it does have CAN options.

I also recently had a problem with an airbag on another car (different make) and bought a OBD2 code reader to erase the error ocdes. It is a universal model covering all makes and worked perfectly on my other car, but it does say that some cars after 2017 have issues. I think the OBD2 standard may have changed around this time to include new protocols which are not compatible with the older readers.

Thanks

I have examined the back of the OBD2 plug and the following pins are wired: 16, 15, 14, 6, 5 and 4

The Torque app tried and failed to connect to the following:

J1850 PWM (41.6K)
ISO15765-4CAN11/500
ISO9141-2 5 Baud
J1850 VPW(10.4K)
ISO14230-4 KWP fast
ISO15765-4CAN11/250
ISO15765-4CAN29/500
ISO14230-4 KWP 5 Baud

The Autool X60 tried and failed to connect to:

ISO-15765 11bit/500k
ISO-15765 29bit/500k
ISO-15765 11bit/250k
ISO-15765 29bit/250k
KWP2000 FAST
KWP2000 BAUD
ISO9141-2
J1850 PWM
J1850 VPW


SZ Viewer A1 successfully connects on: Module (CAN) 33980-78R6*/33980-78R6

Found another post on this forum: www.bigjimny.com/index.php/forum/7-jimny...generation-jb74-2019

My OBD2 wiring is the same as posted by Vice and he states the following based on pinoutguide.com/CarElectronics/suzuki_ob...gnostic_pinout.shtml note however that his reference predates the Gen 4, JB74 Jimny, so it may be inaccurate:

Pin 4 – Black Wire - Chassis GND
Pin 5 – Black Wire - Signal GND
Pin 6 – Blue Wire – CAN High J-2284

Pin 14 – White – CAN Low J-2284
Pin 15 – Blue – ISO 9141-2 L-Line (ISO 9141-2 and ISO/DIS 14230-4)
Pin 16 - +12 v – Battery Power

SZ Viewer A1 is using CAN, the numbers after it relate to the module ID it is connected to, not the standard.

I found this link which explains a bit more about the different standards....

www.csselectronics.com/screen/page/simpl...xplained/language/en

AZ Viewer uses either ISO 9141-2 / 14230-w (KWP2000) on pin 7 or CAN on Pins 6 & 14. SZ Viewer states the protocol as CAN/CAN-UDS, according to this article

www.quora.com/What-is-the-difference-bet...and-the-UDS-protocol

CAN-UDS is derived from ISO 14230-3 (KWP2000) and ISO 15765-3 (Diagnostic Communication over Controller Area Network (DoCAN). That makes sense as the older Jimnys were KWP2000.

Your OBD2 doesn't appear to have pin 7 wired, but pin 15 is wired using L-Line, this is probably why the KWP prototcols fail.

Just looking at Torque, it doesn't list ISO15765-3CAN, just the more standard ISO15765-4CAN, that is probably the reason why it fails. ISO15765-4CAN is now mandatory in the US, so it might be that the some Jimny's come with a different CAN version or still have the KWP2000 available as well.

The Autool list several ISO 15765 protocols but doesn't say which CAN standard they support, I am guessing it doesn't have ISO15765-3, so again this is probably why this fails.

Anton Malykh (SZ Viewer A1 author) would probably be able to help you know which protocol is running in your Jimny, he was very helpful to me last week, just email him. SZ Viewer A1 on my older Gen 3 doesn't have CAN and uses K-line (KWP2000), but I see that at the top or in the PC version.

I suspect that the other person you saw with an Autool working has different wiring or a different standard.

Thanks, this is getting quite a bit more complicated than I had originally imagined!

Anyone know of any suitable software that would be compatible with ISO15765-3CAN?

DrRobin wrote: Your OBD2 doesn't appear to have pin 7 wired, but pin 15 is wired using L-Line, this is probably why the KWP prototcols fail.

its actually very simple to open up the plug on the Autool X60 and move the pins about, any chance that would help?

I am not sure it would work pin 15 is described as L-Line and is apparently just used to wake up the ECU before pin 7 is used, see

www.gendan.co.uk/article_3.html

This is rather interesting since the article says pin 15 was only used on earlier cars and then for K-Line (pin 7) which your connector doesn't appear to have. As far as I can tell pin 15 is not used for CAN. I wonder if your socket is missing a cable by mistake, or deliberate for your market and that makes it CAN only? The ECU might be cable of K-Line on pin 7, it might only lack the cable.

Unfortunately I don't have a Gen4 so can't tell you if pin 7 is wired, but there are others on here would be able to have a look for you.

I agree with you, it is crazy, a standard that is not a standard, but I see this all the time in my job (I am an electronics design engineer, specialising in router design and data comms systems).

Just seen this

'Using KWP2000 on CAN with ISO 15765 Transport/Network layers is most common. Also using KWP2000 on CAN does not require the special wakeup functionality.'

from en.wikipedia.org/wiki/Keyword_Protocol_2000

So L-line (pin 15) is not used for wake up when using CAN, so either Suzuki wired it anyway or they missed off pin 7.

If we have any JB74 owners from italy on the forum, could you please post a photo of the back of your OB2 plug.

Actually, it might be interesting to see how a UK JB74 OBD2 plug is wired too, anyone willing?