Hello, I've had a loose positive battery terminal (bolt was broken, had a vice grip on it) for a couple months now and occasionally the car would shut down and restart mid-drive. After fixing the terminal it no longer happened. The day before I took it in to get fixed however, I noticed the traction light was on along with "DSC not available text". The suspension was also quite stiff like it had been pumped up to max setting. Additionally the doors don't look with my fob. Battery is 2 years old. Took it to my indy mechanic. He cleaned the ground terminals behind the front headlights, did a hard reset and then read the codes. Only that that came up was C2785. He did try a thing on his computer for recalibration but it required a code on the top of the steering shaft. Not sure what to do from here. The x350 fb group suggested I use the code from an ebay listing to try and recalibrate it, but maybe its something else?
As far as I can think there are 3 options:
Replace the battery just to make sure
Try the reset with my mechanic (may require dropping the steering shaft)
Bring to a dealer (last resort)

 

I think the approach is wrong, the DTC C2785 does not affect the steering angle sensor, but the Yaw Rate sensor. It is located in the J-Gate assembly on the right side and there is no need of codes from the steering column. .
First the vehicle should be read out with SDD (original Jaguar OBD software). If SDD confirmes the DTC C2785 particular pinpoint tests are provided in the WSM. The sensor is measured electrically and i.e. checked for power supply, ground fault, high resitance. SDD provides the test information and is able to calibrate the sensor.

The sensor is not necessarily defective, but it delivers implausible values. Cause can also be a ground fault or a too high resintance at a connector.

I would look for an independent workshop that deals with Jaguar vehicles of this decade and has access to genuine OBD equipment.

Fritz

 

Replace the battery

 

Another vote to get the car hooked up and read by an SDD. Your code points to a bad YAW sensor but I hate to throw parts at the car until we are sure of the problem.
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With the bad terminal and cutting out, chances are that has thrown up a lot of codes due to low voltage, and sensors not beige read properly. Now the terminal is repaired, get the battery checked, if it's good, clear all codes, take it for a run and see what comes back. If it's bad, get it replaced then do the same.

These cars do not like bad batteries, even a slightly low battery can cause havoc. So a dodgy terminal is going to cause all sorts of problems to pop up.

 

Just replaced the battery, cleared codes and still the issue persists. Im thinking of ordering an SDD now

 

Which issues are still there, have you read for codes again, has DTC C2785 reappeared, is the "DSC not available" message still there and the traction light still on, have you driven the car at all since replacing the battery, it may need a few drive cycles to "reset" any codes or faults that were stored in the ECU.
A bad ABS "wheel speed" sensor affects a number of systems, ABS, DSC, traction control, even vehicle speed readings. and as the ABS sensors do not always throw up a code, the computer can be fooled into thinking another system is at fault.

As for the FOB, is that still not locking the car, and do all the other functions on the fob work ok? It may sound like I have shares in a battery company, but again, I'd change the fob battery and give it another go, it's only a couple of bucks, so can't do any harm.

 

Correct, same issues along with DTC code C2785. I will try another hard reset today. I never had an issue with ABS so I'm thinking its not the speed sensor? My guess is some kind of module was thrown out of calibration that requires SDD to fix.
That is a good point about the fob I will try.