Typical, I started the car up to head off for the annual MOT, and the engine check light went on, P0138. I drove around for a bit to warm up the engine than did a stop, restart and the MIL light cleared itself.

I stuck on the tester and got the following.



The car passed the emission test no problem, here are the test results.



Could have just been an intermittent connection issue I guess.

Has anyone seen this error code before?

 

To flag the code (& put on the MIL) it has to occur on 2 successive warm ups in similar conditions. That's to meet the laws on OBD (and is in the Jaguar doc).

To auto-clear it, the condition must not have occurred for 4 warm ups.

I'd say it's not intermittent but it would be easier to troubleshoot if it keeps happening.

Due to its meaning you may want to inspect wiring etc!

It's quite likely it cannot flag again unless the P1000 changes to P1111 - and in case the fault recurs then that may or may not happen.

 

I can't see how this can be the case.

"To auto-clear it, the condition must not have occurred for 4 warm ups."

It cleared on the next start up after first appearing.

Anyway I will check to O2 sensor connectors and monitor to see what happens over the coming weeks.

 

Something very wrong, then. You can always read the rules (laws) of course in case I've misinterpreted them but they seem clear.

 

No engine light on and MOT passed with flying colours, What's very wrong?

 

Your apparent experience if reported accurately.

MoT currently does not check OBD monitor status here, so P1000 does not matter to MoT (but does to you if you want a working car).

 

This car has always shown P1000 since I bought it 7 years and 40000 miles ago. Still dont see anything "very wrong" with it, and has run pretty much perfectly over this time.

 

It definitely hasn't run "perfectly" in that case. You may be happy of course.

There will be codes it can't flag but you may be lucky (or unlucky) as to what other things the problem(s) (causing the P1000) may lead to. After such a time, you sound to be in the lucky category but many a car would (for example) have burnt out a catalyst or the like.

You're lucky that the UK does not (yet) check the OBD monitors as is intended, and as many regions do, for then your car would fail.

 

So what would you suggest to diagnose what the problem is, given there are no trouble codes and emissions are perfect

 

OBD to see which monitors are not set then find why.

The emissions will not be perfect - the UK does very poor testing... for which you can be thankful.

 

I think this thread makes a very pertinent general point.

An error code can only have two potential causes:

1. There is an error somewhere.
2. The error is itself in error.

Either way, something is not right. There could be a minor malfunction which will lead to nothing, forever, or something more serious, or perhaps a computer or wiring issue, to name just a few.

Either way, I think it important to know exactly what has generated the code (if possible - it seems to me that OBD codes are often horribly vague). The fact that there are no obvious consequences can mask the fact that it may one day develop into something far more serious. Perhaps an unknown code can be safely ignored, but the general point, I would suggest, is that it should always be approached as a priority item.

 

They tend not to be horribly vague on these cars at least, as Jaguar have generally documented every known/potential cause individually for each code. Often leads to just a tiny number of things to check.

Sadly there are exceptions, however...

 

Well there has been salt sprayed on the roads round here over the last couple of days so that's the car laid up for the winter, I had planned to give it the recommended drive cycle to get P1111 and see what, if any of the tests failed, that's now on the back burner till the roads are clean and dry again.

In the mean time I plan to cut out the rusty parts of the floor plan and weld in new sections, pics of that to come soon.