2006 Rendezvous EGR valve replaced twice, service engine light still coming on
dbank1
06-02-2012, 08:44 PM
Two months ago my service engine light came on. Code indicated it was the EGR valve. I had it replaced and the light came on again a month later. The mechanic thought it was an old code and reset it. A week later the light came on again. We replaced the EGR again and installed a mesh filter as a precaution. A week later, the light again came on. Mechanic thinks it may be the MAP sensor. Does this make sense? And if so, any idea on cost?
Tech II
06-02-2012, 09:43 PM
You need a scan tool capable of reading EGR data......I think this EGR has a pintle position sensor......so you use the bidirectional scanner to open the valve a certain %.....then you check to see if the commanded and the actual position is the same.....you also slowly increase the EGR opening with the scan tool, and the engine should run rougher as the pintle opens greater.....
Yes it could be a bad MAP, but usually a bad MAP sets a code....PCM's usually run a test, once the vehicle has reached operating temp, and the vehicle is cruising......on a decel, the PCM will command the EGR slightly open for a certain amount of time...when it does this it looks for a corresponding change in MAP.....if it doesn't see it, it sets a code.....this could be caused by a bad MAP, a bad EGR, or a slight blockage in the upper plenum......
There have been several TSB's on this problem....some involve changing the EGR and harness, and also reflashing the PCM.....
Yes it could be a bad MAP, but usually a bad MAP sets a code....PCM's usually run a test, once the vehicle has reached operating temp, and the vehicle is cruising......on a decel, the PCM will command the EGR slightly open for a certain amount of time...when it does this it looks for a corresponding change in MAP.....if it doesn't see it, it sets a code.....this could be caused by a bad MAP, a bad EGR, or a slight blockage in the upper plenum......
There have been several TSB's on this problem....some involve changing the EGR and harness, and also reflashing the PCM.....
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