The CEL dash light on my 2002 X-Type has come on. One mechanic says, if the car is running ok don't worry about it, while another says, get it sorted coz it will be guzzling extra fuel. Which one should I heed?

 

It depends what the light is for. Could be something minor that you don't have to get fixed immediately. However, it is on for a reason and it will not go away. Eventually it will get worse and could cause other issues the longer you let it go.

From the sounds of your mechanic it is probably a minor vacuum leak. If so, usually those can be taken care of quite easily and inexpensively. Best think would be to post the codes here and we can go from there. Ask your mechanic would the code number is. Without knowing what it is you can't be sure.

 

Jeramia, like Alfa said, it could be something minor and won't affect the overall performance or longevity of the vehicle. Other codes, you drive for 100 miles with it and you are risking serious damage. Get the code(s) read at your local auto parts dealer and tell us what that says. From there, we can give you some pretty sound advice and it may be nothing more than something you can fix yourself in say 15 minutes. Granted, it may be something that will require some significant work. Hard to say with what you have told us about the issue.

 

Thanks guys. The codes I have been given are - P0037, P1646 1647 and 1699.

 

Jeramia, I would first start by checking to make sure that you have good fuses installed in F38 and F42 in the engine bay fuse box.

Granted, the P1699 code is indicating that you have a CAN bus failure between the ECM and A/C control panel. I would say to clear all the codes and see what comes back. Then lets see what you have then. The other codes and the P1699 codes are not related. So, I am thinking the P1699 might be an old code and not part of this problem.

 

I don't know what "can bus failure" means. He cleared all the codes to start with and those are the ones that came up. Do they not indicate any specific or dangerous faults?

 

Jeramia, the CAN bus is simply a communications network between the various computers of your car. In your case, you have a problem with the 2 wires running between the ECM and the A/C control panel. There isn't anything that you can really do to check the wiring other than possibly some simple electrical checks. But, that is only going to tell you if the wiring between the two points is good or not. It won't tell you if the modules are good. You would need a dealership computer to do that.

As for the other codes being "dangerous", it is hard to say. It is all a matter of how rich the engine is being run. If you are running it too rich, then you are going to destroy the cats. If you run the motor lean, then you can damage the pistons due to them getting too hot (hence why the O2 sensors are used to monitor the gas/air mixture).

 

Sorry Thermo but much of what you say makes no sense to me!! All I can gather from your posts is, apart from checking some fuses, (all ok), or plugging in to a Jag Dealers computer, there's nothing I can do about my CEL. Is that correct?

 

Jeramia, the CAN bus is simply 2 wires that go from one computer to another. In the simpliest of terms, one wire is on the transmit of one computer and the other end of the wire is on the receiver of the second computer. The other wire is set up so the second computer's transmit is wired to the receiver of the first computer. This allows the computers to talk to each other and share information. If you break this information path some how, then the computers cannot talk to each other and the computers are not going to get the information that they need to control things. Unfortunately, you can create as much damage as you may fix by getting into things without a basic amount of knowledge of how these sorts of things work. Hence why I say to take it to a shop to have them look at it as it sounds like you are not familiar with this sort of technology.

You are correct that based on what it sounds like your abilities will allow you to do, your best bet is to take the car to a shop to have them connect up a computer and see what they say. Beyond that, not much you can do unless you intend on learning a lot about your car.

 

To keep your eye on things cheap OBD2 port , code readers , are available from car stores & Ebay . I bought mine Ebay ( £14.99 UK ) They usually come with a booklet of Generic codes , or you can look them up on the web.

 

Thanks five speed but I already got the codes and been told there's nothing I can do except go to a dealer, so buying a cheap reader won't really help. Thanks anyway.