Chrysler Repair: 2001 Dodge Grand Caravan Check Engine Light Code P1494, dodge grand caravan, rodent damage

Question
My van currently has 98K miles on it.  I have 2K more miles on the extended warranty.  A couple of months ago, my check engine light came on.  The dealer rebuilt the transmission under warranty.  A month later, the check engine light came on again, Code P1494.  They replaced the Leak Detection Pump.  About 3 weeks after(1 week ago), the check engine light came on for the 3rd time in less than 2 months, Code P1494.  The dealer said they needed to replace the LDP. I reminded them that they just did that.  So, they kept my van all day and called and told me that the problem was that rodents had chewed a spot on the harness wire (the first time I'd heard of such a thing) so they had replaced that and charged be approx. $200 for labor, for the time it took them to figure out the problem, since the warranty didn't cover rodent damage.  The very next day, my check engine light came on again (4th time), Code P1494. I took my van in this morning, they said they would make sure that all the work they had done was okay and then try to find the problem.  As of the end of the day today, they still have not figured out what's wrong, and they still have my van.  Any suggestions on what might be wrong with my van?  Thanks for your time.

Answer
Hi MaryAnn,
They are looking at the right part of the system. The only other possibilities are an obstruction in the vacuum supply hose at that pump, and verifying the wires to the pump switch sense circuit, and try wiggling wires while the system is activated. If all that checks out and the fault still won't cease, the last option is replacing the engine controller. The most important thing is to save your repair documentation so that when/if the odometer passes the 100K mark and the problem persists you won't have to hassle about it being beyond the warranty.
Roland