Fault Codes

[DougX]

In two weeks time my XK8 is booked in for a MOT. Today, I undertook a diagnostic check to see if all was OK. Now wishing I hadn't. The following codes came up and the diagnostic unit (iCarsoft V3) was unable to clear the faults, so I have to assume that they still exist.
The codes were C1417 C1425 C1430 B1402 B1234 B2322 B2327 U1041 U1135

Any help with these codes would be appreciated.

[mike020150]

The codes are not MoT issues. They relate to the adaptive dampers, windows, seats, mirrors etc and suggest that signals from those items are not being passed correctly through the various checking procedures. If they are to be believed, the car's ride should be very firm because the adaptive dampers will have defaulted to their firm setting. You need to have the codes cleared and then see if they return. They might relate to earlier faults, now corrected. Mike.

[DougX]

Thanks Mike, for some reason they won’t clear, which I have to assume means there is still an issue. One of the things I have read about is that a low battery may cause issues. Checking my battery voltage with the engine off, is showing 12.3v. Could this be the reason?

[mike020150]

There's no doubt that low battery voltage is responsible for many spurious code recordings. However, just reading static battery voltage alone isn't enough to condemn or eliminate the battery. Testing needs to be done with a commercial battery tester. Once the battery on any modern car reaches 4/5 years, it has to considered a prime suspect for spurious dashboard lamps and/or codes. You could simply replace it to eliminate it from the investigation (say £150?) or have the battery tested properly which shouldn't be expensive because it only takes a few minutes to do (my local garage tested mine for free when we were having a debate about battery lives!). Some codes seem reluctant to clear with non-professional tools, so again, it would be worth using a specialist garage to clear them to ensure they aren't just old stored codes. Alternatively, if the dampers, seats and mirrors etc are all working correctly, you could just carry on enjoying the car without doing anything! Mike.

[DougX]

Hi Mike, I also messaged the Service Manager at my local Jaguar franchise dealer. I had sent him your original explanation and he wrote back saying, " The two 'U' codes are modules talking to each other. The others are most likely to be what JEC have said. Not too much to worry about." The car is in for service just after Easter and will have them check to see if they can remove the codes. All the items indicated with these codes are working perfectly.