Hi , we have a X350 2004 which was running ok until heavy rain overflowed the cabin filter due to a blocked drain below the cabin filter. The car was switched off and locked after a drive and after the rain the cooling fan was running at high speed on its own, i removed the engine ecu and had some moisture inside and this was the main problem,. I dried the ecu out and refitted and read the ecu and has no fault codes , also cluster has no fault codes. The engine cranks but will not start or fire. removed 2 plugs and look dry and no spark at all.
checked the inertia switch and also seams ok. I think the body computer is next to the engine ecu and will try my other Autel computer to see if i can find any other fault codes. When the rain got into the engine ecu relays were clicking in the engine bay fuse box. No fan is on now and cant see any other problems . need to check fuses and scan rest of car for faults next.
On my X300 the immobilizer in in the body ecu and not the engine ecu. Is the X350 the same setup ?
Engine cranks and no spark or fuel i think as plugs look dry but did smell fuel from exhaust while cranking. i have worked with electronics for many years and can not see any other problems inside the ecu. I think water was just over the multiplug pins of the ecu under the pcb and so inputs were causing fan to run etc Right Hand Drive UK Model with ECU / Cabin Filter mounted under Glove box passengers side
Thanks in advance