Help with P1494

[Castro661]

2000 Jeep 4.0L manual.
I’m getting code p1494 leak detection pump fault…
I replaced the LDP and nothing, replaced gas cap and nothing, replace the solenoid and nothing, I even did a smoke test and I had no leaks.
Checked all elbow and hoses all the way to gas thank and under the battery but they all looked good.
Have smog check coming up next month. I’m out of ideas and could use the help.

 

[Chris]

The P1494 code typically indicates a leak detection pump (LDP) circuit malfunction. Since you've already replaced the LDP, gas cap, and solenoid and performed a smoke test with no success, here are a few other possibilities you could consider:

1. Wiring Issue: Check the wiring harness and connectors related to the LDP circuit. Make sure there are no loose or damaged wires, and ensure the connectors are securely connected.

2. Vacuum System: The P1494 code can also be triggered by a problem in the vacuum system. Inspect the vacuum lines and connectors for any cracks, leaks, or disconnected hoses. Pay particular attention to the lines around the engine bay and firewall.

3. Electrical Grounds: Ensure that all electrical grounds related to the LDP and associated components are clean and securely connected. Corroded or loose grounds can cause electrical issues.

4. PCM reset: Try disconnecting the battery for about 15 minutes to reset the Powertrain Control Module (PCM). Sometimes, a simple reset can resolve certain intermittent electrical issues.

 

[Castro661]

The P1494 code typically indicates a leak detection pump (LDP) circuit malfunction. Since you've already replaced the LDP, gas cap, and solenoid and performed a smoke test with no success, here are a few other possibilities you could consider:

1. Wiring Issue: Check the wiring harness and connectors related to the LDP circuit. Make sure there are no loose or damaged wires, and ensure the connectors are securely connected.

2. Vacuum System: The P1494 code can also be triggered by a problem in the vacuum system. Inspect the vacuum lines and connectors for any cracks, leaks, or disconnected hoses. Pay particular attention to the lines around the engine bay and firewall.

3. Electrical Grounds: Ensure that all electrical grounds related to the LDP and associated components are clean and securely connected. Corroded or loose grounds can cause electrical issues.

4. PCM reset: Try disconnecting the battery for about 15 minutes to reset the Powertrain Control Module (PCM). Sometimes, a simple reset can resolve certain intermittent electrical issues.

Thanks
I checked vacuum lines and all seemed good, I checked the connections and seemed good, I haven’t reset the pcm I’ll try that next and I’ll double check everything.

 

[rdu-jeep]

Thanks
I checked vacuum lines and all seemed good, I checked the connections and seemed good, I haven’t reset the pcm I’ll try that next and I’ll double check everything.

Ever figure this one out? I am chasing a P1494 on my 2001 TJ Sport

 

[mjtjnj]

ditto. mine came on essentially after sitting all winter,
with a few starts