badly need s-type help before the baliffs come!

the story

so a common problem occurs ie eml light is on and the performance restricted on and off - i take it to the jag dealers - deep breath - £375 later the knock sensor is changed - problem still there - back to dealers £90 diagnostic check says wires between sensor and loom, checked fine - back to dealers £135 later the service people say plugs the issue (quote £475) - i change the plugs - problem still there - i notice the a/c is blowing hot on the passenger side could this be linkied - i badly need some help to sort this car in the next week or so and i actually can't afford to take it to the dealers! please help me techy type people or next time i will buy a german car!

 

I don't know but the first thing you need to do is list details of your car. Year, engine ect.

 

Then you need to get the codes read and post them here. My guess is your going to have P0171 and P0174, engine running lean. Possibly misfire codes as well.

Your AC (heat) problem is a whole different issue. Use the search feature above "DCCV" you will find your answer there.

 

sorry its a 2004 3.0 v6 petrol s type. and the code is p0333 - which is the knock sensor high output according to jaguar.

 

I guess the RH knock sensor was replaced for the 375, that was a rip off, simply because thats the easy one to get to should not have taken an hour total to replace.

P0333 is the LH knock sensor which is located under the intake, is there a chance that it was unplugged, after you changed out the spark plugs? Although it doesn't have to be disconnected. The manifold will have to be removed to switch it out.

 

not likely. jaguar claim it could be just that the system needs their computer (again) to be reset is this possible?

 

Computer reset won't cure a code (it will at most hide it temporarily). But if the fault has gone the code will be erased anyway - no need to connect anything. So, they appear to have told you complete rubbish.

There again, maybe they just want the car back so they can fix it properly. And maybe PRETEND the computer did it. So long as you're not paying, could be worth playing along.

 

Uh jagv8, now you know codes have to be cleared wether the problem is fixed or not. Theyll be stored as historic and will fail an emmissions test for a stored code, light on or not(not that they have them in scotland)

 

We do have emissions tests but stored codes will not cause a fail. (Being over the emissions limits at the tailpipe will.)

If the light's off in the USA it's my understanding that a fail will not occur - is that not right?
(It's certainly right over here, whether Scotland, England or wherever.)

The codes are completely deleted after a sufficient number of drive cycles, aren't they? (Typically 40 or 80.) Or is this another area where the laws differ?

BTW, the OP refers to the eml light being on .... and problem still there (and it being P0333)... which was what I was addressing. Clearing the codes as I said won't cure a fault

 

In the US, doesn`t an OBMII fault cause a failure for emissions testing? Pretty sure it does......

 

Yes if MIL light on, but otherwise? Would be a bit daft, but after Brutal's post I'm left wondering.
(It's not a "fault" if the light's off, it's just a stored code, is my understanding.)

 

A ck engine light on as well as codes without a light that pertain to emmissions and engine performance, misifries, sensors. 02, knock sensors, egr, evap system, etc will be read by the emmissions monitor and fail the test, so will have more than 1 monitor "not ready" from clearing codes, or disconnecting a battery and not completeing the reuired drive cycles. It varies here state to state but for the most part is pretty much the same. Except for mass, and jersey. Theyre in a world all their own for state inspections from my understanding. And on drive cycles clearing codes, after alot (like 50, at least that was the number on older odb1 jaguars) odbii is very differant. And on the later jaguar like the 07 and up xk, xf and the new xj's i can see all codes ever flagged from when the car had no miles and up with sdd. Just like your home pc, just cause you delete something doesnt meen its "really gone" any good pc person can pull up everything unless you electronically shred it

 

Even if you can read all (historical) codes, they're not part of OBD-II unless they fit the mandated standard

This "emmissions monitor" you mention..... comes as rather a surprise as it's not in the standard nor have I heard of it. Tell me more, please!

Disconnecting the battery's not relevant here as it would clear the very codes the OP says he has but which I understand keep coming back.

(We're way off the OP's problem lol)

 

I never said "all" i do believe i reffered to mifires, 02, sensors(not all), evap system, etc...yes not all codes are part of obdii.

Emmissions monitor aka component monitors, aka diagnostic monitors. Aka odb readiness monitors all 1 in the same there are 6

heated 02 sensors monitor
adapt fuel monitor
misfire monitor
cat efficiency monitor
evap system monitor
comprhensive component monitor(engine/trans)

i was not reffering to the op issue for a battery disconnect, besides on obdii disconnecting a batt doesnt clear anything except volatile memories.(of which codes are not)
Just as a refferance since i have to do state insp for other techs and they waste my time by not telling me theyve programmed a car, cleared codes or replaced/disconnected a bettery. Therefore causing a inspection failure, requireing the car to be driven through drive cycle to reset monitors and making me redo a state inspection wasting my time. Its was purely info

on the p0333
poor sensor contact with block
ks to ecm sense circuit high resistance, open circuit, short to ground, short to power
ks failure.
If the ks is new(new ever worked) i would pin the sense circuit and the ks contector for all the above conditions
if that doesnt show issue and the ks was properly installed, may want to swap with another to see if the problem moves (i have been burned by "thinking" a new part was not the problem just because it was new and exhibited the same fault)
past that its a circuit fault in the ecu and ecu's can be repaired by a rebuilder especially if you state the issue with the circuit and pin #

 

Well, there are often more than 6 monitors. But my question related to those historical codes (those not commanding the MIL on). They won't cause monitors not to run and won't cause an emissions fail, will they?

Unready monitors (depending on how many etc) can cause a fail but that wasn't in my post.

 

Correct, there are more than 6, and some less than 6 but depends on yr make and model, what i listed if out of the x and s type book. Monitors run not based on faults, but fuel level, time, brake application etc. Theyre differant requirements for differant monitors too much to list out. And no only the codes that pertain to emmissions and engine/trans management will cause a failure on a emmssions state insp test




yes and also that depends on yr, in texas 2001 and up cannot have more than 1 monitor not ready. 1995-2000 can get by with 2 not ready.
Funny thing too is that normally when you need to state a car and a monitor is being stubborn and not resetting its the 1 your repaired and are worried about the repair since it might be intermittent and as soon as it checks the monitor, bang the fault returns and you get to try again

 

Adr147, here's my four penn'orth about your problem for what it's worth.
I used to get the MIL light coming on intermittently, say around once a fortnight, together with obviously restricted performance, apart from it telling me so in the LCD window.
Now, having much experience in the electronics field with microprocessor controlled machinery, I'm quite sceptical about error codes from 'computers', as I found the codes were often caused by things other than the faults the codes were supposed to reveal.
About six months or so ago, I fitted a 68,000microfarad capacitor at 25volt working across my battery with a 3amp fuse in series for safety. Since then, the car has NEVER gone into limpmode+MIL light, NEVER, not once. And I've not done anything mechanical or electrical to influence it.
Not saying it will cure your problem, just my few cent's worth. There is a posting of mine somewhere outining why I think the problem is happening, just search for it. One of these capacitors only costs a few dollars and is easy to fit with crocodile/alligator clips. For your handy electronics helper, about half an hour's work. Get him to make it, you clip it on yourself.
Leedsman.

 

interesting idea but i can't see how that can work! i will look into it though. jaguar still insist its a wiring fault (and are sure they can fix it for about a grand!) - the car runs and drives perfectly other than this, its very odd.

jagv8 and brutal i am a total geek on my subject (snooker / pool cues and equipment) but you two really are on a whole new level, its what i love about forums the depth of knowledge an enthusiast has can frighten the punter. i am still open to ideas for my eml light and a/c problem.

 

Putting a big capacitor across your battery? Why can it work? I suppose it's a bit like understanding quantum mechanics -- ordinary intuitive logic doesn't fit.
Leedsman.

 

That's a diesel car, with an entirely different PCM (lots of other differences, too, such as very high fuel pressure). Also, an entirely different problem to any others I've seen on this forum. And a different fix.

I think you could help others by putting your car details in your signature (see below).

The fix might apply to the petrol (gas) cars but I doubt it.