Question

code P1494 on a 1999 Plymouth neon. what do I need to do to get engine light off for this problem. not sure what a vapor leak detection pump is or where it is?

Answer 1

Here  is an explanation of the code and possible issues that cause it:

SYMPTOM 
P-1494 LEAK DETECTION PUMP SW OR MECHANICAL FAULT

WHEN MONITORED 
After a cold start, with ambient temp between 40 and 90 degrees F and the coolant temp within 10 degrees F of ambient temp.

SET CONDITION 
The LDP switch is not in its expected state when engine is not running. After an engine start a change in switch state is not seen when the LDP solenoid is energized to pull the pump diaphram to the up position.

POSSIBLE CAUSES 

 

• Fused ignition switch out circuit open
• LDP pressure switch circuit short to ground
• LDP switch sense circuit open
• LDP wiring and/or connectors obs def
• LDP wiring harness intermittent failure
• Leak or obstruction in vac hose
• Leak detection pump defective
• PCM def (LDP system)