There clearly seems to be problems with Astra EGR valves. Iíve read so much on various forums that Iím close to confusing myself as to what to do next. Please advise.
NOTE: Iíve also posted this on the Astra forum as I understand my engine is the same, i.e. Astra 2.0 DTI (2002 / 52 reg).
P0400-(9): Exhaust Gas Recirculation Valve Feedback Signal Malfunction Ė Not Present
EGR Valve Ė Inactive
EGR Position Command Ė 100%
EGR Pulse Ratio Ė 95%
EGR Feedback Ė Okay
There was also a MAF sensor failure but this is because I have it unplugged at the moment (with it plugged in, the revs are limited to 3000 but it takes about 60 seconds to climb to 60mph Ė not very safe for road use. With the sensor unplugged it is still limited to 3000 revs but you can climb through the gears much more quickly, in fact a lot quicker than when the car is working in fault free conditions. This is not a good solution and is temporary until I fix the real problem. The sensor has only been unplugged for a few days).
BTW, the diagnostics were read with the MAF sensor installed. I cleared the MAF sensor failure, did a refresh and the above fault remained.
3 years ago my Astra 2.0 DTI (2002 / 52 reg) Engine Management Light (EML) started illuminating 1 week after I bought it. The EGR was removed and cleaned by a garage which fixed the problem for a short while, maybe a week or two.
Took it back to garage, this time the EGR was replaced. Fixed the problem for a few weeks. Since then the light has been on and off intermittently, but mainly off. A restart of the engine usually did the trick and got me home.
During that time I had a fault code telling me that the diesel pump needed replacing. I didnít trust this so the garage cleared the fault and told me to return when the EML next came on, which was the next day. This time no fault logged, just the EML.
Since then Iíve lived with the problem until it became a permanent fixture recently.
A friendís diagnostic tool was not completely compatible with my car, but it did show a problem with the MAF sensor flickering between hot and cold readings. I replaced this which fixed the problem but the EML was still permanently illuminated.
I bought a compatible OP-COM diagnostics and got the readings shown in the summary above.
It sounds like it is stuck in the fully open or closed position based on the ĎInactiveí and Ď100% positioní diagnostics. However, the Feedback Signal Not Present error code suggests to me that there is a communication / wiring problem, but the EGR feedback is ok.
Clearly I donít really know what Iím talking about but I canít afford to keep taking it in and out of garages, and I canít afford a new car. Would cleaning the valve help? Would replacing it help? The EGR was cleaned and replaced when I first got the car Ė is this really still the same problem? Could it be ECU related rather than the valve itself? Are there any guides on how to perform ECU wiring checks Ė I have a digital multi-meter.
Should I just give up and never by Vauxhall again?