Leak detection pump failure can be caused by the internal diaphragm switch sticking, or in some cases, contamination from debris or carbon particles from vapor canister. If black carbon particles are present in the LDP, replace vapor canister in addition to LDP. The purge solenoid should also be checked for debris or carbon contamination and replaced as necessary. All evap system hoses are subject to cracking and splitting causing leaks, Inspect hoses carefully. In cases of contamination from carbon particles or debris, all hoses and tubes must be blown out with compressed air to remove contaminates.Google+
Car Problem Reports
Dodge Ram Van 1500 LDP failure due to carbon from vapor canister
Dodge Ram Van 1500 Problem
Visitor, 2001 Dodge Ram Van 1500, 246,237 mi
i have dodge ram truck 1500 v6 3.9l 2001 automatic. my problem is my detection pump solenoid is always blew up.i've been replaced so many times but still blew up. its been done the diagnostic test.they found the code P1994.i've been replaced the purge solenoid,LDP,carbon cannister,gas cap,computer.they've been done smoked test has no leaks. i just removed the wire harness to check the votage.i've been checked the power i have 13 volts but the other terminal i have only 2.3 volts. can you make some explanation about this matter.could help me about this problem.