KDM

The current at the battery from the alternator is reading 14.58V. I do agree there could be a parasitic draw which does requiring a check fuse by fuse, unless there is a quicker way? I am charging the battery and will drive tomorrow, let see what happens. I am still leaning towards the battery as I can drive for one hour and the limp mode still happens which does point to a battery not accepting or retaining charge. I may get the battery tested tomorrow.

Hi John, So I measured the battery this morning, it read 12.16V which is very low. I opened the doors from a distance and didn't take the key fob as not to activate too many items on the car. With engine running I measured the alternator output at 14.58V which would appear correct as far as I have read. So simple test, am charging the battery and will reset ant DTC's, measure battery and then see what happens next. The battery is less than 12 months old so under warranty.

So I can rule out the battery, what should be the minimum power in the battery before the car throws a wobbly? I have measured tonight when I arrived home and its 12.48 V. Is that too low? I will check again in the morning in case its draining somewhere. Appreciate any advice on the voltage.

Thanks for the link, found the undertray part number. Now to find one for a reasonable price....

So I tried the Vincheck and apparently my car is in the US and its a 4.2Ltr.....

Thanks Jim. Its weird that the 2008 cars do not appear in these catalogues, the reference numbers are not for my vehicle so back to the search....

Thanks Clive. My vehicle is March 2008 built and I understand the missing trays are different in shape to what is shown in the link. Will keep looking.

I have searched before posting but unable to locate the part numbers of the various undertray pieces. I am missing the section that covers the engine & gearbox. I have the front section and the L/H & R/H 'wings'. Any assistance on these missing piece(s) would be appreciated. 2008 XF 2.7D.

Just to update, replaced the diaphragms and there is a difference to the car, however, the limp mode is still there but more manageable. However, I have been using SDD to understand the DTC's and I have hit a brick wall and do require some assistance. If anyone knows of a SDD specialist who can remote assist then please do suggest. Thankyou in advance. My thanks to Vic for suggesting the vacuum issue, I will be arranging a smoke test on the turbo side as there maybe a leak that is causing the limp mode.

Hi Vic, The vacuum suggestion is good, I know the rubber diaphragms can split and there is a repair kit available. I will test it first, assuming I can find them. Tried replacing the batteries with no change, my power supply has arrived so hopefully tomorrow I can wire up the car and use SDD to verify the fob. Onwards and upwards.

Hi Vic, The vehicle is a 2008 XF 2.7D. The codes are in the first message. The fob stopped working when the battery was disconnected for a week or so, the fob works perfectly when inserted so will try to wake them up through SDD. The RFA shows a big red cross on when checking the modules on SDD. Previously there was a fault code with the MAF's so when cleaning didn't work I replaced the two and a new air filter and no fault codes for the MAF for the past 150 miles. The limp mode is restricted performance / DSC not available..... and with the fault code generated by the ABS ( See first message ) is the reason I was moving towards the wheel sensors. Three times today with limp mode, so frustrating.

So just to update, having fully charged the battery the issue with restricted performance is still occurring. Some of the codes have disappeared which may be due to the battery or some of the work I have been applying to the car. I have cleaned the earth points in the boot, under both front wing liners, and behind front N/S light. Does anyone know of any more? I am working through SDD and its pointing towards ABS issue, am planning to change all 4 sensors this week. Any other advice or suggestions would be welcome.

Thanks John. The battery is less than 6 months old, and I will remove it and fully charge it and hope it removes some of the codes. I did try once before with no difference to the car. What is a short journey? The car travels at least 18 miles each way twice a week, what mileage is minimal for charging the battery? No stop / start as its a 2009 Model.

Reaching out for some help as I've hit a wall with understanding why the Cat is not working properly. So I have the following issues: 1. When driving the car ( or sitting still and revving higher than 3000 ) the car goes into limp mode, DTC not available etc.... 2. Recently the key fobs stopped opening/locking doors, the fob still works when inserted and car functions normally. So I have the following codes: Instrument Cluster Control Module U0214-00 This refers to the keyfob issue P0635-11 This refers to a power steering issue. HVAC Module B11FF-84 This refers to lack of gas in system. BCMB U0264-00 States ignore this DTC. U0214-00 No info provided BCM U0214-00 No info provided ABS Control Module U0401-68 Invalid data received from ECM/PTC module. RFA module not responding - tried to test through the SDD but failed. So, I need some help understanding the consequence of the RFA not working and what exactly it is.... Could this be causing the limp mode? If anyone in the Swansea area ( happy to drive further ) can assist then I am happy to pay ... Thanks in advance.

Just to update, MD wants around 3.5K to change the chain etc.... Still hoping for some suggestions pls.....