[Frontier Fan]

We have a 2009 Nissan Frontier with a bit over 118,000 miles on it. The Service Engine Soon light came on a short while ago. Took it to the Nissan dealer. Dealer replaced the charcoal cannister, evaporative sensor, and vent valve. Total charge: $935.14. A short time later, the Service Engine Soon light reappeared. The OBD code was "P0183 Fuel Temperature Sensor A Circuit High." Back to the dealer. They replaced the fuel pump. Total charge: $962.26. Within only a handful of miles away from the dealer, the light came on again. Same OBD code. What is going on? Is this reasonable or should we be concerned? Thanks in advance for any help.

 

[VStar650CL]

The fuel temp sensor will read "high" from an open or high-resistance ground, and Fronties, Titans, Xterras and older Pathies are infamous for getting blackened ground terminals at the fuel pump connector. People often replace pumps and never notice the condition of the connector. There's also a huge connector on the righthand frame rail that joins the Chassis and Engine Room harnesses, and they sometimes get water intrusion since they're out in the open. One of those may or may not be your issue (usually a bad ground causes wonky fuel gauge behavior too), but it definitely sounds like a wiring problem of some sort.

 

[Frontier Fan]

Thank you for your reply. I assume I can get a cleaner from an auto parts store, but can I reach the connectors? I have read that to replace the fuel pump, the shop had to remove the truck bed. I doubt that is possible for me.

 

[VStar650CL]

It's actually easier to run the tank near empty and drop it than to remove the bed. To get at the pump connector only requires tilting the tank, with one strap off and one loose. To remove the pump is a different story, for that you need clearance.

 

[Frontier Fan]

Thank you again. I saw that there was a YouTube video where someone dropped the gas tank, but I hadn't watched it yet. I guess I need to do that now.

 

[El Ti9re]

Hey, did you get this fixed? I'm having the same issue. I ordered an aftermarket fuel pump assembly from Carparts.com with fuel temp sensor, bc my fuel gage was not working correctly. I replaced the entire unit, again, with a fuel temp sensor, and a few days later I got a P0183 code. Im unsure how to test the harness with a voltmeter, but I am getting resistance and conductivity from all pins except the middle (there are 5). I ordered a wiring hardness and MAY replace that too.

 

[VStar650CL]

Hey, did you get this fixed? I'm having the same issue. I ordered an aftermarket fuel pump assembly from Carparts.com with fuel temp sensor, bc my fuel gage was not working correctly. I replaced the entire unit, again, with a fuel temp sensor, and a few days later I got a P0183 code. Im unsure how to test the harness with a voltmeter, but I am getting resistance and conductivity from all pins except the middle (there are 5). I ordered a wiring hardness and MAY replace that too.

The fuel gauge and the FTT sensor on the Frontier share ground, but both sensors ground through the instrument cluster and not the ground wire for the pump. The Brown wire on pin 2 at the pump is the shared sensor ground. Inspect that connector pin, and ohm that wire from the pump connector to the chassis. You should see a reading near 0 ohms. If it's higher but the pin at the pump connector is clean, check for water intrusion into the big Chassis Harness connector under the truck (on the frame rail behind the righthand fender). If you've had a current or past exhaust leak, also check for harness damage along the frame rail where the exhaust pipe and Chassis Harness are in proximity. The nose-piece on the pump connector just pries loose, and it's much easier to see problem pins with it removed. This one is a 2-pin, but the 5-pin on the pump will pop apart similarly:

 

[El Ti9re]

The fuel gauge and the FTT sensor on the Frontier share ground, but both sensors ground through the instrument cluster and not the ground wire for the pump. The Brown wire on pin 2 at the pump is the shared sensor ground. Inspect that connector pin, and ohm that wire from the pump connector to the chassis. You should see a reading near 0 ohms. If it's higher but the pin at the pump connector is clean, check for water intrusion into the big Chassis Harness connector under the truck (on the frame rail behind the righthand fender). If you've had a current or past exhaust leak, also check for harness damage along the frame rail where the exhaust pipe and Chassis Harness are in proximity. The nose-piece on the pump connector just pries loose, and it's much easier to see problem pins with it removed. This one is a 2-pin, but the 5-pin on the pump will pop apart similarly:
View attachment 8690

Hey bro, thank you for replying. So I tested the hardness with a multimeter, testing the shared pin (on the temp/fuel gage) and got 0 olhms. I traced the connectors to the big switch behind the passenger wheel, and it all seems to be good; no discoloration or nothing. I used dielectric grease at the female connectors on the big switch to improve connectivity. I did the same at the fuel pump connectors and re-assembled. I will see if the problem persists.

 

[El Ti9re]

Hey bro, thank you for replying. So I tested the hardness with a multimeter, testing the shared pin (on the temp/fuel gage) and got 0 olhms. I traced the connectors to the big switch behind the passenger wheel, and it all seems to be good; no discoloration or nothing. I used dielectric grease at the female connectors on the big switch to improve connectivity. I did the same at the fuel pump connectors and re-assembled. I will see if the problem persists.

Just an update, I guess adding dielectric grease at the harness' (fuel pump and C1) really did the trick. I reset the codes and driven (now) around 20 miles and no more P0183! Thanks for your help!

 

[VStar650CL]

You're most welcome, happy motoring!