engine pictogram

[phirouyer]

In the rev. counter circle, there are a number of pictograms which show when you switch on the ignition, including the pictogram of an engine. This pictogram would come off as soon as the engine is running. Recently, I noticed that this pictogram would not come off, and would stay permanently. Is it an indication of a fault ? The driver's handbook does no say much in this respect.
I checked the battery. It is OK. I disconnected the battery, in order to reboot the computers. Sometimes it does the trick, but this time, to no effect.
I must add that the engine runs smoothly, gas mileage is as usual, the idle is perfect, everything works as it should. Does anyone know the meaning of this signal ?

[3.8etypephil]

You will need to read the fault code(s) via the OBD to be certain, but if the car runs normally, it's probably a defective lambda sensor, or a poor electrical connection.

[J44EAG]

The orange "pictogram" is known as the "engine check light".

Illumination of this light signifies that there has been an under bonnet "event" during your journey. Even though the light illuminates, the car is safe to drive. The engine check light may also be accompanied by a message centre advice of "restricted performance". Diagnosis using dealer level IDS/SDD equipment or a DIY tool such as a Foxwell or iCarsoft 930i unit will frequently also reveal a fault code or two.

A generated fault code points in general terms to fault in part of the vehicle management system. As an example, a specific code such as P0171 or P0174 points towards an air leak/lean mixture issue on Banks A & B on a supercharged V8 engine. The fact that 171 & 174 might have together generated a fault code implies a communal issue. As air leaks are most likely above or below the throttle body on a supercharged car, the fault is likely to be caused by leaking supercharger pressure or vacuum pipe. In such an instance, one is lead to this area of the engine. The most obvious place to investigate is the stub pipe atop the pressure manifold on the supercharger. Usually, one will find a badly rotted 3mm ID pressure pipe. Replacement restores equilibrium to the system. The owner uses a diagnostic tool to clear the historic fault code, the engine check light extinguishes and the problem goes away until the pipe falls to bits again in a few years time!

My best advice would be to invest in a diagnostic tool such as the iCarsoft unit. I`ve had mine for years and regard it as an essential onboard tool. Occasional faults can be kept under control with it and high garage diagnostic checks avoided.

Mike K

[RichardSEL]

There's a used iCarsoft 930 for sale on the Jaguar Classified's site -- £55 down in Plymouth
http://www.jaguarclassifieds.org.uk/ind ... &highlight

[phirouyer]

Thank you all. I understand that this pictogram is the equivalent of the well-known check engine light of the XJ40.

My car is a 2001 3.2 model. I will have it checked but I'd suspect a poor connection rather than a faulty lambda sensor since the idle is perfect, gas mileage as usual, and I have not noticed any loss of power.

[phirouyer]

I had the car checked. We found a 0420 and 0430 error code = Low efficiency of both catalytic convertors. Next step will be to find out the origins of this "low efficiency"...I hope I don't need new convertors, because they cost of fortune.

[J44EAG]

Check the efficiency via an occilogram which will show what the Lambda sensor are doing. I got a P0430 recently and changed the NSR post cat sensor which was flatlining and messing things up. Fitted a new sensor and the issue disappeared.

Mike

[RichardSEL]

Cataclean does actually help the older catalytic converters -- used it on my Sport ('01MY) and have only had one 0420 since.
And that after some spirited kick-down acceleration away from a Golf GTI that insisted on being too close in the rear on the M3

There used to be a probe that could be connected to an RS232 port on a PC.
With the supplied software your PC could act as an oscilloscope. But I dunno what's available nowadays.
What do you use Mike?

[J44EAG]

There is the facility on the Android/Iphone/ELM327 chip and Torque Pro app. PTJS1 and I set it up on my phone as a separate screen which is quickly and easily used....once you get it set up.....! You need a twelve year old phone boffin to achieve that!! Great once it is part of the set up.

Note the left hand sensor graph. This was due t the rear near side sensor going duff. Here it is doing a fail. Plummeting trace with the flat line along the bottom just about to begin. Sadly I didn`t capture that as an image.

Mike K

[phirouyer]

End of the story : I had the exhaust gaz analyzed. Figures were satisfactory on both sides. The check engine light has gone. The idle is perfect, gas mileage as usual, engine running smoothly and no pollution. I'll wait untill the check engine flags again.
I was surprised that both catalyst converters would be down at the same time. I suspect that P0420 and P0430 appeared for another reason.

[J44EAG]

A typical Jaguar glitch.

I had a slight air compressor issue last year. No amount of hard dumping or diagnostic tool intervention would clear the fault code. I`d put a new piston ring on the compressor and changed the filter media a couple of days previously. I drove the car and nothing occurred for the next two days. Then the MIL issue happened. So I locked the car and went on the internet. One fellow said he had locked his car and walked away for twelve hours. So I did the same. I started the car twelve hours later and the MIL lamp and fault code had cleared itself. Nothing as queer as a Jaguar that has the grumps.

Mike K

[phirouyer]

I totally agree with Mike K. DTC codes are a great help but they are not the Word of God. My opinion is that any default detected by a diagnostic tool should be confirmed another way. It is true that only an pscilloscope will tell with certainty the condition of a lamba sensor. And it is really worth investigating before ordering some truly expensive parts.

[RichardSEL]

Looking back in the history of "Ludlow" (my exec XJ8 '01MY now with 112k on) a previous main agent that shall be nameless (Marshalls) used by the first owner had an 0420 so they changed the cat. Few weeks later there's an invoice for another 0420. So they changed the sensor. No more invoices in the file for that.

@Mike: Did you have to get a separate probe to connect to the sensor's terminal and chassis for those readouts?
Thanks for the info -- saved -- there's some cheap IPhone 9 and 8 around now refurbished (hint @Santa)

That's a good check if you've got a sensor that's failing fairly soon after start up. But some age and only fail very occasionally. I've had the Sport since September last year and did the Cataclean treatment in November last year.
Last Sunday week was the first time since my yellow engine check icon's come up after some spirited driving

And it hasn't happened at all to me with "Ludlow"

[J44EAG]

The connection to the Android phone and downloaded Torque app is in the case of the oscilloscope and other Torque attributes via the ELM327 V1.5 chip which plugs into the OBD socket. In the case of the X350, it is below the steering column trim on the extreme left hand side. My own unit stays permanently in the socket unless removed for use by my iCarsoft unit or an Independent Jaguar garage for more in depth investigation.

Mike

[RichardSEL]

I always take my iCar Soft out with me whichever XJ8 I use
Her indoors seems to prefer the Exec ...

Emissions codes don't respond to a "hard reset" disconnect of
battery for 15 mins I've found

I'll look up that ELM chip stuff you mention as it's not expensive

Here's a DIY method --
http://www.instructables.com/id/Use-You ... illoscope/
Or attach an Apple USB adapter and a stereo A-D converter available online,
view via the app ONYX 3 (£9.99) from Amazon