My beloved 04 coupe Black 104K kilometers. Trying to put a few extra miles on the car before winter...so drove to bowling, no problems but it set a code on the way home P0106 MAF. I had had the engine beauty cover off earlier, so I thought perhaps the rubber was not seated properly on the plastic intake. May as well take the MAF off and clean the little wires. I have done this successfully on my Ford Ranger. ( PS easiest to remove the whole rubber elbow assembly with only two plastic arm clips holding it to the aluminum intake.) Completed the job with sensor cleaner and re-assembled. Get in the car and crap, it wont start, no crank at all. Absolutely nothing to do with the MAF work I was doing. Put in my spare RCM and moved the car to a safe out of the way place in the shop. Once more I find myself examining the Bad RCM on the test bench. Thanks to the forum I have a schematic. All fuses good. The three little troublesome solder pads look perfect under the microscope. So I checked the engine control relay contacts. perfect shiny smooth. Checked coil resistance (relay 2 and 3 are in parallel, so you expect about half of 75 ohms of a single). Applied 12V to Connector D2, ground on B5 and both relays should click in. Aha! RLY 3 DOES NOT PULL IN even though the coil has continuity. I wired in a spare relay to the #3 RLY solder pads just to see if my test jig was wired correctly, and yes the spare relay pulled in no problem. After that, presto, as if by magic, Relay 3 started to work, likely due to messing with the solder pads. It has to be replaced since you cannot leave an intermittent relay in service. I have seen relay coil go bad, but this symptom was new to me. The Crossfire will post multiple codes if the Engine control relay does not work. It is responsible for powering MAF, Fuel Pump, Injectors, Cam position sensor, and telling the PCM it is active. I think I did the MAF service for nothing. IF you don't mind me saying, the XF is the most annoying and troublesome car I have ever owned and this is my second one. My advice, don't go anywhere without a spare RCM and a crank position sensor. Oh yes, I washed it.
Nov 30th 2024. On yet another trip to the bowling alley, I stepped on the throttle and let the RPMs go nuts to pass a few cars. Apparently when I floored it the vacuum had reached atmospheric indicating a leak. Bingo on comes the CEL indicating Manifold Absolute Pressure (MAP) sensor reading out of range. This little guy is readily accessible so I pull it off and have a look. Nothing to it. A little vacuum dashpot. The vacuum line had perished right at the sensor, so I just cut off half an inch and put it back together. I graphed the MAP readings on the scan tool, and all normal again. Reset codes and no more lights. I think it is time to replace a bunch of small vacuum lines as a preventative maintenance item.