How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Mike V. Your Own Question
Mike V.
Mike V., Auto Mechanic
Category: Dodge
Satisfied Customers: 23636
Experience:  25 years automotive expierience, Nissan factory trained, Subaru factory trained.
Type Your Dodge Question Here...
Mike V. is online now
A new question is answered every 9 seconds

I have a 1999 Dodge Caravan with a trouble code P0455 (Evaporative

This answer was rated:

I have a 1999 Dodge Caravan with a trouble code P0455 (Evaporative Emission control System Leak [gross leak]). I repaired a vaccum leak and replaced the pvc valve as well as the hose (cracked
Greetings and welcome to JA! I will do my very best to assist you with your problem.
OK, this code is for the evap system and not the engine. This is why the code came back on you.
The most common cause for this code is either a bad leak detection pump, faulty fuel cap or fuel filler tube. The LDP is located under the van in the area of the rack and pinion. If the tubes have come off or if the pump has stopped pumping it will cause a large(gross) evap leak in the system
Customer: replied 6 years ago.
How do I test the pump for propper operation?
Here is the procedure! Hope it helps!
1. Remove all of the rubber evaporative hoses to check for deterioration from the inside out.

2. Check the purge solenoid. It should block vacuum when de-energized.

3. To check the Leak Detection Pump (LDP), connect a test light to the Yellow/Black (YL/BK) wire. The test light should light with the Key On Engine Off (KOEO).

4. Start the engine and ground the White/Dark Green (WT/DG) wire with a jumper wire. The test light should go out.

5. Remove the ground and the test light should light up again.

6. Remove the large outlet hose from the LDP that goes to the canister and block the nipple on the LDP.

7. Ground the White/Dark Green wire and the test light should go out.

8. Remove the ground and the test light should stay out for at least 10 seconds if the LDP is good.

9. If the test light lights up within 10 seconds after the ground is removed from the WT/DG wire, the LDP is leaking.
Mike V. and 6 other Dodge Specialists are ready to help you

Related Dodge Questions