im richard new jag owner and new to forum it is still taking me a little bit to figure things out i never been on a forum before so this is new so here it goes.

i bought a 04 jaguar xjr with inoperable cruise just displays message cruise not avaliable. i dont know much about jags and how to read codes either.

i was a mechanic and could figure it out in time but i need research. but im wondering if this is common failure and one componet is usually at fault but i dont know for sure.

any help would be greatly appreciated as im having hard time figuring the forum out.

thankyou richard

 

Hi Richard,

Welcome to the Jaguar Forums!

Is the cruise control system on your car the conventional type, or is it the Adaptive Cruise Control that maintains a given distance between your car and the one ahead of you?

Your car will have one or more Diagnostic Trouble Codes (DTCs) stored related to your "Cruise Not Available" warning, but a standard OBDII scanner cannot read the Jaguar-specific codes related to the cruise system. You'll either need to visit a dealer or good independent Jag specialist to have the codes read, or invest in a computer-based system such as a Mongoose cable and dealer-level System Driven Diagnostics software (SDD). Use the Search window at the top of this page to find information on various options.

Some owners have reported that their Cruise Not Available warning went away when they installed a new battery, so it might be a worthwhile first step to measure the voltage and current of your battery while cranking the engine at startup. Various gremlins are known to occur if the voltage or current dips too low while starting the car.

As a tip for achieving better results on the forum, note that many members will not bother to read a block of lower-case text with no line breaks or capitalization and minimal punctuation. Their eyes will just glaze over. Reading posts like yours is hard on the eyes and limits the number of potential replies you may receive. I have taken the liberty of adding line breaks to your post, but I don't have time to add capitalization and punctuation. I highly recommend that you do this yourself on future posts.

Please let us know if you have conventional cruise or adaptive cruise and what codes show up when you have them scanned.

Cheers,

Don

 

Thankyou don for the tips. I have adaptive cruise and i will try to get the codes and let you know richard.

 

Hi Richard,

Some of the common problems associated with the adaptive cruise control are:

1. Low battery voltage/current;

2. Blockage of the forward looking radar, which emanates from the Adaptive Cruise Control module (ACC), which is mounted behind the front bumper on the left side;

3. Improper levelling of the ACC module;

4. Loss of communication between the ACC module and the Engine Control Module (ECM). This can be due to corrosion on electrical connectors or the ground stud used by the ACC (behind the left headlamp), a short or break in the wiring harness, or ACC module failure.

I would recommend this sequence:

Have the stored codes scanned and write them all down;

Clear all the codes;

Re-scan the codes to see which ones remain, and make a note of which ones have a solid chain link symbol (permanent faults) and which ones have a broken chain-link symbol (intermittent faults).

Cheers,

Don

 

You might try a 'hard reboot'. Disconnect the negative clamp from the battery, leave it aside for about 20 minutes, and then reconnect the clamp. Hopefully that fault will clear.

 

You have to know the codes first. Could be a CAN-bus error communicating with the module or a faulty module itself. If you can get to the modules with SDD you can reprogram it and see if that works. New modules are expensive I believe so you can also disconnect it and switch over to conventional cruise control. For that you need the SDD software too.

Guus