Previously my 2006 XJ V8 passed California's smog check, where the car was put on rollers and a probe put in the tailpipe to measure actual emissions. At some point California stopped measuring actual emissions, and now only scans the OBD port.

There are no error codes displayed on the dash, the car is driven an average of three times a week for +20 miles each trip, the battery is good and has not been disconnected since maybe 6 months ago, and there are no drivetrain malfunctions except rarely the engine will die when cold and coming to the first stop.

At two smog check stations my car will not communicate at all with the new California code readers, and there is power at the OBD port. Both stations say this is the first time they have seen this with thousands of cars tested.

This doesn't seem to be an engine or emissions problem, but a mismatch between the Jag and emissions reader software, and seems likely to affect many other Jags.

I have been recommended to go to a car software specialist and will report back what I find. If there are any other ideas or experiences would appreciate hearing those. Thanks.

 

Hi XJPurr,

The first thing that comes to mind is to visit a local chain auto parts store such as O'Reilly's, AutoZone, Advance Auto, NAPA. Most of those stores will scan your car for any stored OBDII diagnostic fault codes. If their scanners can communicate with your car, the problem may be in the new California system.

If their scanners can't communicate either, then you know the problem is with your car. If so, I would recommend finding a good independent Jaguar mechanic or Jaguar dealer service department with the necessary system to read not only the generic OBDII fault codes (P, or Powertrain codes), but also the proprietary Jaguar codes (C/Chassis, B/Body, and U/Undefined (mostly Network)). You may have a problem with the Serial Data Link/Serial Communications Network, the Controller Area Network, or another system. If so, one or more U-prefix codes may be stored which will help diagnose the cause of the problem.

Please keep us informed.

Cheers,

Don

 

I would get an elm327 and then:
1. check for stored codes
2. with engine running look at which OBD monitors are NOT set
3. hot engine, parked, check fuel trims (LTFTs) at idle then at about 2500rpm

Do not clear codes! You will also clear ALL the monitors if you do.

If the elm327 does not work you can be almost certain you have a problem (fuse/wiring/...) with the OBD socket.

 

Independent shop that is expert in CA smog checks worked on it all day, they mumbled something about monitors and said I have to go to Jag dealer. Ok.

 

Thanks for the update, XJPurr.

Please keep us informed.

Don

 

What they mean is they don't know much about OBD...

 

Cerritos California Jag dealer charged $323 for diagnosis, and identified about $2200 in worn out suspension bits and leaking motor mount (car is 10 years old, less than 90,000 miles, driven easy and kept in garage). Says car's computer communicates with all three of their machines and indicates no engine or emission problems.

Says they can do the smog check and issue the certificate. When they attempt to connect to California state computer it immediately rejects them because manufacturers are not "Star" certified testers.

I have been to 3 independent California smog testers, at least two of which were Star certified, and they all say the same thing the car won't communicate with their machines and manufacturer must do the smog check. The manufacturer says they can't find a problem and California won't let them do the smog check. Appear to be checkmated.

Made an appointment Monday with California smog referee. This state has 21 locations where smog check problems can be addressed. Car is now out of registration and we'll see what happens, very frustrated.

 

That is truly frustrating. I still think it would be worth visiting an auto parts store like O'Reilly's, AutoZone, Advance, NAPA, etc. to have them try to scan your car (for free). If their generic scanners can communicate with your car, that will be strong evidence that the problem is with the new California system and would be good ammunition for your meeting with the smog referee.

 

I wonder why this is the first/only car with this issue?

 

Fairly recently California changed from a tailpipe emissions test to only scanning the OBD port for cars past a certain model year such as my 2006. Maybe few XJs from that era have been tested under the new system, or maybe this car has a unique problem.

Retrieved the car from Cerritos Jag and it runs and drives magnificient and looks beautiful as always, that's why I put up with the headaches.

Monday will visit the California smog referee station. Hope they can complete the smog check, and at the least should have more info what's going on.

 

I guess it depends on the equipment that these Smog places are using.

Maybe they can only read HS-CAN and MS-CAN, and maybe not the SCP and ISO protocols that are used on an X350.

The PCM in the X350 is HS-CAN but the "diagnostics" over the OBD port is on the ISO 9141...

In saying that, there's a statement in one of the JLR tech guides;

"For the 2008 model year, the CARB (California
Air Resources Board) required the automotive industry to
switch from serial data diagnostic communication to the
CAN communications standard (ISO 15765-4) no later
than the 2008 model year. Certain Jaguar vehicles complied
early to the new standard. S-TYPE and XJ complied
starting with 2006 model year. 2007 XK was built to the
standard, and X-TYPE became compliant in 2008."

So who knows... but for sure if the dealers equipment (IDS/SDD) can read the car and there's no communication errors, then the problem is with the Smog stations equipment...

 

What's the last six digits of your VIN, starting with G or H?

 

H08352. Wish I could have observed the various techs then I could have given more information. As it is I can only relay what they told me.

 

That VIN is absolutely a 2006MY so according to that Jag tech guide, it should be fine...

 

should be ...

All of the different protocols are based on committee authored specs.

Give two programmers a copy of a protocol spec and you will get at least
two different results.

Sometimes for interoperbility, the only thing you can do is to observe
what the market leader does and copy it. No matter how wrong headed
their implementation happens to be.

I run into this on a regular basis.

 

CARB were very good at specifying each of the protocols was allowed as per SAE/ISO specs and the Jags definitely follow them.

(Won't be MS-CAN, BTW.)

Possibly the car in question has some issue (bad wiring or some such) but fairly easy to check with a meter / an elm327 I suspect.

The smog station is maybe a suspect. I've seen OBD tools (prpfessional ones at that) which failed to follow the ELECTRICAL spec never mind the software!!

 

The California smog referee hooked up his first machine and the car immediately failed due to no communication. The first attached picture is that machine and its readout, and even with my limited knowledge I can see all the blocks read "unsupported" and that indicates no communication. Then he hooked up his second machine and it also failed on that one. There was a paper printout which seemed to show some data, but it has a "?" in many blocks. Referee says problem is with the car can't proceed any further until repaired, and non-proprietary equipment needs to be used. He wrote some more things down but I left the paper in the car.

In retrospect I am really surprised the dealer with their advanced equipment who was told three smog repair shops already said communication problem, gave the car back to the consumer saying they can't find anything wrong! One of the techs probably could have hooked up his personal code scanner and could indentify it's not working.

I will call the service advisor tomorrow to see if they will take the car back and try it again without their proprietary advanced manufacturer equipment, and then once the problem shows itself they can reflash the computer or whatever needs to be done.

The car being tested before mine was a gorgeous black/black XK convertible around the era of my car or maybe a few years older. The referee also failed it although sounded like a different reason, and as the lady was leaving she said maybe she shouldn't have bought it.

 

If it's at all helpful, our 2004MY had no problem with the new California OBDII testing procedure. This was less than 30 days ago.

If I had to take a guess, I would say the state machines may be improperly programmed. See the note above about the protocol changing in 2006. IOW, it's working on an '04 but not an '06 when there was a change in protocol.

 

I know I keep beating this drum, but why don't you visit an auto parts store and have the car scanned for free? Better yet, visit three auto parts stores from different chains. If their generic OBDII scanners can communicate with your car, you'll have a strong argument that the problem is with the new State system.

Based on the information Cambo posted, one possibility is that the California system was programmed to communicate with your 2006 car via the pre-2008 serial data protocol ISO 9141, while the car is actually communicating over the 2008 and later CAN ISO 15765-4 protocol. It may be possible for the system operator to open a screen that shows which protocol the system is attempting to use.

Cheers,

Don

 

And buy a $5 or $10 elm327 as well.