I have a 2001 XKR that has been in long-term storage in my garage (California). I run it periodically and tried to get it smogged. There was a bad coil and the carbon canister recycle signal wire had chafed on the body and broken. After I fixed these, I went to the smog shop but they couldn’t get an OBD2 reading to show codes had cleared. I have various OBD2 readers and also couldn’t get a reading.

i bought a fancy iCarsoft i930 reader, which claims to able to read Jaguars and had a weird result. It reads Jaguar’s inbuilt diagnostics information very well and gives all sorts of data. However it won’t read the OBD2 data that comes through the same socket!

it’s obviously not a fuse issue, as the socket is definitely powered and giving data from the ECU, just not the OBD2 data I need.

Anyone come across this before and have any ideas?

I hope ECUs don’t ‘go bad’ standing in warm garages near San Diego, where the temperature never varies between 40 degrees and 90 degrees.

Thanks, in advance for any help.

Tim

 

The car has more than one data network at the socket - they use different pins and different protocols. The standard OBD information and fault codes are on the ISO-9141 network. The extended Jaguar specific information is on ISO 15765-4 CAN (11 bit ID, 500 kbaud). They both use the same socket, but different pins. Maybe you need to manually set your code reader to use the ISO-9141 network?

It would also help if you told us what data you can read, and what you can't.

I would be suspecting bent/dirty pins or broken wires at the connector before thinking any modules have gone bad. You can find the pinout for the connector in the wiring diagram for the car.

 

Thanks a lot Dibbit. That’s very helpful, knowing that there are two different data networks running through the same socket. The Jaguar diagnostics information seems to be everything that they offer through that interface. There were no errors via that mechanism. What I’m actually looking for is cleared DTC codes for smogging the car (California). Unfortunately these have to come via the OBD2 network, and have to be gleaned by the smog station before they’ll give you a clean bill of health, to prove you’ve fixed any issues.

With your information I can pull the socket apart and test various pins and connections to try to trace back where it’s not working.

Thank you.

 

You need to double check this yourself, but I think its pin 7 in the connector that is used for the OBD2 (the ISO 9141 K line). There are also two separate fused 12v supplies at the connector (pins 16 permanent & 9 ignition switched), two permanent grounds (pins 4 & 5) and two ignition switched grounds (pins 8 & 1) . My notes are below for the same car as you. Let us know how you get on.

6 & 14 Major Instrument Pack (CAN High CAN Low ISO 15765-4) “CAN”

12 & 13 ECM (Vendor Option - ISO 9141) “Serial & Encoded Data”

10 & 2 SCP (J1850) “SCP”

7 & 15 Serial Data Link (ISO 9141) ““Serial & Encoded Data” (I believe the K line Pin 7 is the one used - there are some references that early cars need pin 7 and 15 joined to work)

4 & 5 Ground

16 ==22== B+ (Always on) Figure 01.2 Fuse #13 5A Drivers Side Fuse Box

9 ==42II== B (Ignition Switched II) Figure 01.4 Fuse #5 5A Trunk Fuse Box
8 ==18I== (Ignition switched Ground Position 1) Figure 02.1
1 ==4II== (Ignition switched Ground Position 2) Figure 02.1
(With Electrical Guide ==reference numbers==, pages and fuses)

 

A lot of OBD tools can't cope properly when there are several protocols present (as lots of Jag models have). (It's the tool to blame. OBD II can have 3 or more protocols.)

Worse, some tools don't look properly for the address of each module and can be fooled. You might be suffering this.

If you can persuade the tool to ignore some protocols or only look at one, try that.

I would not join pin 7 & 15 (or any others!) without being 100% sure it's OK (which it likely isn't).

 

Apparently the AutoEnginuity Proline reader wouldn't connect on pre-2003 models without this. This was fixed on later models of the reader. Incidentally the symptoms were exactly as described by the OP - reader won't read the standard PIDs but will read the extended PIDs. There are quite a few threads on the forum about this if you search. I agree though - don't do this unless you know what you are doing!