Try removing fuses F32 and F36 in the power distribution box. That will remove all of the power feeding the ECM. That should allow the memory to clear without clearing the radio and other electronic goodies.

 

Hard reboot is pull the positive cable(engine off key off) touch it momentarily to the negative cable or ground to discharge capacitors erasing volatile memory in all ecu, including clock, windows, radio and sunroof which all need to be reset afterwards

 

OR, you can do it when the light is on or off. It doesn't matter. What you are doing is removing power and forcing the computer to run off of any stored electrical energy inside of the computer module. There isn't much, but I would say that you need to let the car sit with both fuses removed for about 5 minutes before re-installing the fuses. Whatever you do, DON'T!!!!! remove the fuses with the engine running. It will cause the engine to turn off.

Another note when resetting the ECM, the first few take offs and stops should be done in a general manner (ie, no hard accelerations, no emergency stops, etc). The car is attempting to learn how you drive normally and figuring out when it needs to disengage the torque converter, when to drop the engine RPM, etc. So, drive normally for a few minutes.

 

One of my x types temperature, heat, A/C, unit (unit deck above the radio) stopped working, I had a local, "honest", mechanic run the codes, and he said the car is giving mixed codes, as in it cannot tell what is wrong, the mechanic said there is more than one computer "code" box (is there) in these x types and one (not sure which one) appears to need to be reprogrammed.


What happened was; last winter (the car had been sitting for quite a while) I drove the car, on a "very" cold day, the heater began reading in Celsius, then stopped working all together (went out).


What can I do to try and reprogram the car myself. My local mechanic is clueless (specializes in American), and I do not want to go to the Jaguar dealer again; as they don't appear to know much more (or they say)except use my cars (and my bank account) as guinea pigs and charge me a fortune. Last time I needed a catalytic converter in my other car and they tried selling me an O2 sensor, which my local mechanic said I did not need (I didn't) for over well $300, then told me $5,000 for the catalytic converter before labor, so I bought two after market catalytic converters for $330, and paid my local mechanic $700 labor; saved a lot.


How do I re-program my x types computer system to get the heat back on; Please help...

 

Baby Jag, first off, welcome to the Forums. Lots of good information here and lots of people willing to help. But, please stop by the New Member Section and tell us a little bit about you and your car. We pride ourselves in being a better car group and as part of this, we like to get to know one another. This also benefits you in that you will get to meet those that make this place what it is. So, grab a cup of joe, sit back, do some reading and things will be back in a jiffy.

As for your problem. If you are getting really odd-ball codes that are not making any sense, I would start with having a load test done on your battery at your local auto parts store. If your battery is below say 75% capacity, replace the battery and see what that does for you. Our cars are very sensitive to a weak battery and if it is starting to go, the computers will do some really strange things.

If you are looking at replacing the module for the A/C-heat, get a new controller and install it. No programming is needed. Just make sure to get the connectors made back up. if you are looking at replacing the ECU, the TCM, or the ABS module, then you are looking at a trip to your local dealership most likely unless you can find a module from a vehicle with a VIN code very close to yourself with the same sort of options.

 

I read somewhere that you can reset the computer by cold starting the car 5 types. Is this true? Thanks.

 

Jane, it really depends on what you mean by "resetting the computer". If you are trying to clear the codes out of the computer, then NO, this will not work. If you cold start the car 5 times (doesn't need to be a cold start, but simply starting the car 5 times and letting it run for 5 minutes roughly each time) and there are not problems noted, on the 6th start, the computer will turn off the check engine light (CEL). But, the code(s) will still be in the computer for someone to read. But, if at any time an error is seen during the 5 start/stop cycles, the counter gets reset and you have to drive the car 5 more times to clear the CEL light.

Hopefully this makes sense. There is some truth to what you are saying, but not to the degree that it makes some think.

 

So I changed the fuel pump on jag and since then my car starts but it won’t stay started,everytime I come to a stop the car shuts off.The mechanic that worked on it said I need a new full body throttle sensor and a peddle sensor.So once I do this what’s the best/Cheapest way to factory reset my computer?

 

Turn off the car, disconnect the battery, wait 5 minutes, reconnect the battery. Done. That will clear all memory from the car. Granted, you will need to reset your windows and radio, but that is small potatoes for what you are trying to do.