Mine won't start occasionally. By removing and replacing the#47 trunk fuse it will start. That is the fuel pump fuse. It isn't blown. I have replaced it anyway. Same results. I also tried a 20 amp instead of a 15 amp. Same results. Any ideas ? Thanks

 

You may have a bad fuel pump relay. Also, the immobilizer/theft-deterrent system can shut off power to the fuel pump as well. Have you scanned for error codes and if so, what are they?

 

It displayed a PO460 . It either starts or not. No starter engagement or fuel pump prime unless it starts. Dead silence when it doesnt. I pulled the left kick panel to watch the immobilizer next time it fails.

 

po 460 fuel level sensor "A" circuit. This was displayed when it came home on the rollback. Sorry for the delay

 

Usually a code such as P0460 has detailed help in the workshop manual - is there none?

At the very least, all the possible causes are usually listed.

 

2003 OBD codes here:

http://www.jagrepair.com/images/Auto..._OBD_II_R2.pdf


That's a fuel level sensor fault, which may not necessarily be related. However, this circuit goes through the Rear Electronic Control Module (RECM), as does the fuel pump control circuit. Open up your trunk and check the spare tire well for water. These cars are notorious for rainwater collecting in the trunk, which can wreak havoc with the electronics back there.

 

How reliably can you duplicate the fault? When the car acts up, do you have time to do a click test of fuel pump relay R15 in the trunk? The big question is if it is receiving the normal command to energize the pump. Put your finger on this relay and have a helper turn the key to Run or Start. You should feel the relay click. Check carefully, as other relays in the vicinity may also click at the same time.

Wiring diagrams are here, see figure 03.6 for relay R15 and fuse F47:

http://www.jagrepair.com/images/Elec...al%20Guide.pdf


I'm not entirely sure of the purpose of the short wire containing fuse F47. It runs between R15 and the RECM. Not positive, but I THINK it tells the RECM that the pumps have been commanded to run. F47 feeds the RECM. In a similar fashion, fuse F48 goes to Fuel Pump 2 Module. I'm not sure if R15 and these 2 fuses are only carrying a light amperage signal, or the higher amperage to actually run the pumps. I'm also not sure how this would all tie into the no crank condition, but who knows.

Oh anyways, based on your observations about F47, it might be worth swapping R15 with another relay for troubleshooting. R1 would make a good donor. It is for the heated rear window circuit. Make sure the rear window heat is working, so you know the relay is good. Swap them and see what happens.