trouble code P1495 99 Cherokee xj 4l
 

Not sure what to do here leak detection code...were do I look or does something have to be replaced. Idling rough.

Thanks

Code P1495 sounds like you have a Leak Detection Pump (LDP).

The diagnostics manual suggests that there is a problem with the LDP solenoid circuit, but that you say your engine is idling rough suggests that there may be a vacuum leak in the LDP vacuum system.

Could be both, so you should check the vacuum line that goes from the intake manifold (see pic. The red cap is where the LDP vacuum source would hook up) to the LDP. Check for disconnected elbows and holes chafed in the tube. There's a large tube that goes from the LDP to the Evap Canister under the Jeep. I don't think it would cause your problem, but check it anyway.

It is not unusual for the solenoid on the LDP to fail or there is an open in the wiring to the solenoid. Remove the connector from the solenoid and inspect the pins and cavities for corrosion. Inspect as much of the wiring as you can access for chafing/bare wires. If everything checks okay, you may want to replace trhe solenoid or the LDP.

P1495-LEAK DETECTION PUMP SOLENOID CIRCUIT

The state of the solenoid circuit does not match the PCM’s desired state.

Possible Causes:

LDP SOLENOID CIRCUIT WIRING HARNESS OBSERVABLE DAMAGE
LDP SOLENOID CKT WIRING HARNESS INTERMITTENT
GENERATOR SOURCE CIRCUIT OPEN
LDP SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
LEAK DETECTION PUMP
LEAK DETECTION PUMP SOLENOID CONTROL CIRCUIT OPEN
POWERTRAIN CONTROL MODULE


LDP: Don't confuse items 2,3, and 4 with the LDP system. #5 connector is the one you're interested in.

Attachment 326568

Vacuum sorce at intake (red cap):

Attachment 326569
TEST

I just had the same exact problem/code with my 2000 XJ. The rubber elbow was old and had cracks in it which caused a vacuum leak and check engine light. It was the one pictured above with the red plug on it. Check this first. I found a new rubber elbow at Advance Auto Parts in the hardware section.

99 Cherokee 4l
 

Put another Solenoid on,still having same issue. Idling rough with codes 201,301 and 1495. Any other ideas?

Thanks for the help so far

99 Cherokee 4l
 

That pic where the Red cap is,mine is caped off?....had to put another PCM on, it ran fine then we had a good winter storm. Acting up since then.

Did you check the integrity of the vacuum line from the intake manifold to the LDP?

Check all vacuum lines from the intake to their respective components.

Not much we can do over the internet. You are responsible for ensuring att your vacuum sensitive components are secure and free from leaks.

201, 301 would indicate the problem is related to #1 cylinder. Which may be totaly unrelated to the 1495 issue, but maybe not. If #1 is running lean from a vacuum leak you may get 201 (#1 fuel injector) and 301 (#1 misfire).

Thank you

"201, 301 would indicate the problem is related to #1 cylinder. Which may be totaly unrelated to the 1495 issue, but maybe not. If #1 is running lean from a vacuum leak you may get 201 (#1 fuel injector) and 301 (#1 misfire)."

If you have a mind to, you can swap #1 fuel injector with another fuel injector position to see if the 201 code changes to the position where you put #1 injector. See if 301 follows the #1 injector to its new position.

You should change the fuel injector o-rings while you have the fuel rail out. The parts stores have them. Made by Felpro.

stephenlutes did you figure out your problem? I have the same 3 fault codes.