Audi Q7 fault codes limp mode

[Nickie94]

Hi guys, just after a little bit of advice. Got a 2010 q7 3.0 tdi. Absolutely love the car. Had a coolant leak which was behind the V and had it all fixed etc got it back and couple days later it started rumbling on start up, gradually got worse within a week. Now its gone into limp mode, engine light, glow plug light flashing and engine shaking like crazy. 

Had all the injectors tested and they all passed. But the fault codes in the system are below.

P102A00 - torque limitation due to coolant temperature (passive/sporadic)

P214600 - fuel injector group 'A' supply voltage circuit open (active/static)

P214900 - fuel injector group 'B' supply circuit open (passive/sporadic)

P24100 - bank 1 sensor 1 voltage too low/air leak.

Carried out relative compression test with picoscope and found compression dropped on at least 1 cylinder, after using a trigger, deduced that the issues would likely be with cylinder #5

Any ideas what any of these or this means. Thank you

[cliffcoggin]

One possible cause is a dying battery. How old is it?

[Nickie94]

It had a new battery in January, not sure what make as the garage I brought it off replaced it

[cliffcoggin]

Was the new battery coded to the car? It needs to be in order for all electronic functions to work.

[Nickie94]

Yeah I've been using it no problem since other than a coolant leak from behind the V :(

[cliffcoggin]

Well that rules out a battery problem. Others here will have more knowledge about the rest of the electronics.