EVAP System - Leak Detection Pump Misdiagnosis
NUMBER: 18-01-00GROUP: Vehicle Performance
DATE: Feb. 4, 2000
SUBJECT:
Misdiagnosed Leak Detection Pump Systems With DTC P1494, P0442, P0455, OR P0456
MODELS:
1997 - 2000 (AB) Ram Van
1997 - 2000 (AN) Dakota
1997 - 2000 (BR/BE) Ram truck
1998 - 2000 (DN) Durango
1997 - 2000 (FJ) Avenger/Sebring/Talon
1997 - 2000 (JA) Cirrus/Stratus/Breeze
1997 - 2000 (JX) Sebring Convertible
1997 - 2000 (LH) Concorde/Intrepid/LHS/3OOMNision
1997 - 2000 (NS) Town & Country/CaravanNoyager
1997 - 2000 (PL) Neon
1997 - 2000 (PR) Prowler
1997 - 2000 (SR) ViperNiper GIS
1997 - 2000 (TJ) Wrangler
1999 - 2000 (WJ) Grand Cherokee
1997 - 2000 (XJ) Cherokee
1997 - 1998 (ZJ) GrandCherokee
DISCUSSION:
During evaporative system diagnosis, Leak Detection Pumps have mistakenly been replaced. A thorough inspection for pinched, kinked, or disconnected supply vacuum lines (as currently listed in the Powertrain Diagnostic Procedures) is a critical step in diagnosing DTC P1494 (LDP SW OR MECHANICAL FAULT). Additionally, the other evaporative leak faults (DTC P0442 - SMALL LEAK, P0455 - LARGE LEAK, and P0456 - VERY SMALL LEAK) should have the supply vacuum lines examined for pinches or kinks prior to any LDP component replacement.
The supply vacuum lines should be checked from the engine compartment all the way to the fuel tank, including the LDP and purge system.
NOTE:
VERIFY ALL RELATED SUPPLY VACUUM LINE ROUTINGS FOR PINCHES, KINKS, OR DISCONNECTION'S BEFORE REPLACING LDP SYSTEM COMPONENTS.
POLICY: Information Only