smutts

Sorry to have not been back, forgot the password & the reset didn't seem to work when I last tried to get in. I'm an engineer, but not from an automotive back ground. As to cars, when younger, I just got fed up with paying experts and ending up walking to a phonebox in the middle of nowhere more often than I would like. The biggest problem with this white smoke issue, is the engine computer doing bad guess work when it gets bad data from somewhere, (didn't computer programmers use the technical term GIGO? (garbage in = garbage out)). The engine computer adjusts and evolves it's settings to what it is told by the various sensors. Unfortunately, if one of the sensors is telling fibs, the computer believes it, rather than saying that's moopoo and ignoring it. This causes the computer to do some weird things with the fith injector, AND IT DOESN'T THROW AN ERROR CODE! so often garages will be helpless as the computer doesn't tell them what to do. If you own one these cars, you need techstream and the right cable, bootlegs from Ebay are available, we were desperate so took the risk, and were ok. I'm always scared plugging one of these cables into a mostly working car, wondering if I'm about to brick the computer. Fortunately it worked. If you look at the table on this link http://www.lexusownersclub.co.uk/forum/topic/74603-p2002-fault-code-is-220d/?page=2 (picture won't post for some reason) The bit that was interesting was my "dpf differential pressure", which was all over the place, and causing the fault due to knackered wiring, and the "exhaust fuel addition FB" which is the fith injector. When the battery is disconnected for five minutes & reconnected, the exhaust fuel addition value will start at it's default which is 1.0, ours when smoking had crept up to 1.45, presumably nearer to 1.0 is good. How do you tell that the DPF is regenerating? When driving, and the pressure gauge and techstream agreed that the dpf pressure was over 5kPa (20 inches water gague) an orange ring lit up around the speedo. I assumed that this was to say the DPF was regenerating, it didn't happen at any set speed, but I can't find any other info about this. Was I wrong? Thing that may cause the fuel addition to go up? These are my guesses..................................................... Wrong DPF pressure data, due to sensor or wiring. Out of spec lambda sensor? or buggered wiring? Buggered temperature sensors for the dpf, or their wiring? "exhaust temperature B1S1" & B1S2 Who knows, but if it's smoking, see what your "exhaust fuel addition FB" value is. Anyone buying one of these cars needs a good hard test drive, just in case the battery was disconnected just before you turned up!

Just a potential FIX for you bashing your head against this particular wall, The problem, a 2008 is220d, 110k miles, with embarrassing quantities of white smoke from exhaust that smells of diesel fuel. My parents car has been smoking like a pig for the last few months, Diagnosis.... Garage condemmed the DPF and replaced it..................Still smokes. Garage says "just keep driving it, the smoke will soon stop"............It didn't Garage says "er, drive it some more"...................Still smokes. Garage yanks the injectors and send them off to be tested, by people who are not idiots..................non idiots send them back with the verdict, injectors are perfect...........................Still smokes. Garage now say they are sure it is the turbo which will need replacing...................At which point I get involved and rescue the car. No sign of misfire, compressions good, no play on the supposedly fragged turbo, no headgasket doom. Not trusting the fifth injector, I unclipped the fuel line and plugged it by clipping another injector on it. Went for a drive, white smoke gone! So confirming fifth injector misbehaviour. Changed the fifth injector, a total git of a job............Smokes, Argh! So it is the ECU telling the fifth injector to keep on squirting. Techstream turns up from ebay, so plug it in. The dpf pressure values are all over the shop, so tee in a magnehelic guage, which disagrees with the values from the software. Wiggle wiring, AHA! Gotcha! Pressure values in the software change in sympathy. So I remade the wiring from dpf sensor to the ECU and then got good values for the dpf sensor pressure. The ECU "learns" whilst you drive, but the corrupt dpf pressure data had totally confused it. Unplug car battery for ten minutes, reconnect, ECU starts to relearn with good data. Relearn the window winders by driving them for a couple of seconds against their stops at each door switch. AND THE SMOKE STOPPED! and mpg has gone up from 25mpg imp to 40+mpg imp. The magnehelic gauge reads 5kPa (20 inches water gauge) when regeneration of the DPF now starts. So to recap, check the DPF pressure sensor to ECU wiring carefully before spending lots of money on the garage partswap goosechase. Good luck on what is a fantastic car. Warning!!!!!!!!!!!! ! I only disconnected the fith injector for long enough for diagnosis, if it is disabled for too long, the DPF will probably clog up! I only disconnected it for 20 miles.