97 Check Engine Soon code P1494

Any specific parts identified as the code reader only gives back Leak Detection, pump pressure or mechanical fault

NO: 18-01-00
SUBJECT: Misdiagnosed Leak Detection Pump Systems With DTC P1494, P0442, P0455, OR P0456
DATE: Feb. 4, 2000
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