I just got this thing last week. I haven't even run a full tank of fuel through it yet. This morning on my way to work and on a very hard decel and left turn I got that awful message but not check engine light. When I got to work I had codes for a MAF circuit voltage too low, a couple of EGR codes, and one for the EVAP switch being shorted (or maybe low voltage) but still had no driveability issues. When I left to go home it stumbled on start up and while driving it bucks when I try to run it hard. My scanner has the MAF sensor flatlined on 0 lb/min. or whatever it's unit of measure is. I wiggle tested the wires at the sensor but it made no difference. I don't see where my EGR valve is. The car supposedly had a wiring repair near the radiator fan recently. Is there a trouble spot there I should be looking for? Maybe a ground location in that area? I'd greatly appreciate any suggestions that might help me get a plan of attack together.

 

I fixed it! Sorta. A blown fuse. It was easy to spot - it was backwards and slightly newer than the rest. Why hadn't I looked there before I bought this thing. I wouldn't look for others. So I replaced the fuse and was instantly restored to full power. I didn't even bother to clear the light. It'll go out soon enough. Or the fuse will blow again in a short enough time that I'll have no choice but to find the short. I think it was fuse 14 (10A) under the hood. The engine controller (what's Jaguar's official acronym?) powers the EGR position sensor, MAF sensor and EVAP switch through that fuse. Hence the cluster of DTC's. I found it while studying wire schematics on my lunch break. We have All-Data at work. It's ok but leaves plenty to be desired. So anyway - before I had traced the map back to the fuse, I was horrified to trace it back to a splice. I could only imagine where this splice was located and how utterly impossible it would be to inspect, let alone repair it. When I followed the path back to the fuse box I became so excited that I couldn't just sit there. I ran full speed out to my car and found it blown.

I bet if I avoid that harsh entry it won't blow too often though. Next time it does blow I'll just try to re-reoute the harness a bit. I'm thinking that when the engine is braking, the reversed torque load is causing the motor to rock the wrong direction. I may even have a worn motor mount letting it move further than it should. When it does move, it's pulling on or pinching the harness so as to create a short. I hope. I hope it's not gonna blow everytime I run an egr monitor or something. That thing pays almost 3 hours according to All-Data, which, by the way, doesn't tell you where the first bolt is.

 

Funny isn't it, I have also had a fuse problem, but on my wife's New Beetle. We decided to get a regas done on the air con because it didn't seem to be blowing cold, (we were in the middle of a warm week in March, very unusual !!). Anyway, regas done but still no air con. Shop finally found the fuse was crumbling away, and the fuse holder too, due to heat damage. Its a 30 amp fuse, so my diagnosis was that some corrosion due to damp had made a resistance there and caused a heat spot. Pushed in another fuse and away the aircon went. However, the fuse holder is being replaced this next week. This fuse box is in the engine compartment and quite near the radiator.