Help 56 error codes from a diagnostic run!!!

[Mark Hez]

Hi guys I got an Amber engine light on last week followed by lots of warning lamps cycling, I got a diagnostic run done by Halfords and it shows (count them!) 56 problems, vast majority are either historic or intermittent but I have 3 permanent, which are parking break control module U0155-0 & U0415-00 TPM, any advice is more than welcome 🙏 

[Jimbov8]

First thing Mark, keep it simple. Check the battery voltage and fully charge if need be. 12.8v is fully charged. Check the alternator output. Check your ground points in the engine room are all clean and tight. Reset the codes and then see what comes back.

[Mark Hez]

Hi Jim thanks for feedback, I’ve just checked my battery cold and it’s pushing 12.4v, then let it idle for bout 10 mins and recorded again at 13,4v, I’m thinking the second reading should be 14.5+? Also I’ve only had my jag since feb, no issues at all , my XF is on a 15 plate and I noticed it’s already got a Halfords start/stop battery fitted, so obviously that’s not a stock battery, so may have had similar issues in the not to distant past, what should my battery be pushing when warmed up and running ? Thx again 

[Jimbov8]

12.4v to start with is a little low, fully charged is 12.8v. With the engine running you should see 14.3v to start with and then reducing to 13.8v.

If your car is diesel then the charging from the alternator may be a little different to that of the petrol version.