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2003 Dodge Dakota P1494 Code: Leak Detection Pump (LDP) Fault - Cold Start Only

Model: 2003 Dakota Fault Code: P1494 Posted: 2009-07-05 09:36

I have a 2003 Dodge Dakota with a 6-cylinder engine, currently at 82,000 miles. I recently installed Bosch Platinum2 spark plugs and the vehicle ran smoothly afterward. However, the next day during a cold start, the check engine light illuminated and displayed code P1494 — 'Mfg Auxiliary Emission System Leak Detection Pump (LDP) Switch or Mechanical Fault'. The code indicates either a failure in the Leak Detection Pump (LDP) switch or a mechanical issue within the emission system. I turned off the warning light and drove approximately 120 miles, repeatedly shutting down and restarting the engine — during this time, the light remained off. However, on the following day, the check engine light came back on during another cold start. My suspicion is that I may have accidentally dislodged or loosened a vacuum hose while installing the plugs, but no visible disconnects were found upon inspection. The issue only appears under cold-start conditions and does not manifest as misfires or other drivability problems. Any insights into diagnosing this P1494 code on a 2003 Dakota? Could it be related to a loose hose, faulty LDP switch contacts, or something else? Thanks for any advice.

Related fault codes
P1494
Comments (5)
Anonymous 2009-07-05 11:25

Unless you accidentally disconnected a vacuum hose near the purge solenoid or Leak Detection Pump (LDP), this issue might be coincidental. Check all connections in the emission system, especially around the LDP area.

Anonymous 2009-07-06 07:18

Refer to the vehicle's emissions system diagram under the hood to locate the LDP solenoid and pump assembly — this will help you visually inspect for loose or damaged components.

Anonymous 2009-07-07 15:02

After a few days of cold starts with multiple hot starts, the check engine light has not come back on. I didn’t notice any obvious hose disconnections during inspection. It’s possible that a slightly loose hose re-seated itself over time. Thanks to Jeff for the helpful suggestions!

Anonymous 2009-07-07 15:49

The Leak Detection Pump (LDP) switch contacts may be sticking — this is a known issue in some 2003 Dodge Dakota models and could cause intermittent P1494 codes.

Anonymous 2009-07-13 07:35

I found the vacuum hose connecting from the throttle body to the LDP runs behind the battery, under the fuse box — it's hard to see due to wiring. The end of this hose was split about half an inch and loose. I was able to snip off the damaged portion and reattach it securely. This likely resolves the issue. Lesson learned: avoid pulling on hoses when installing spark plugs!