Code P0181 Fuel Temp Sensor range

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leedos
Posts: 3
Joined: Fri May 24, 2019 4:55 pm
Car: 2010 G37s Sport Premium

Code P0181 Fuel Temp Sensor range

Postby leedos » Sat Jun 08, 2019 5:13 pm

I recently purchased a 2010 G37 with 132,000 miles. The car as a problem with the power steering and also has a reoccurring check engine light with code P0181 for the Fuel Temp sensor. Google didn't turn up any common fixes except replacing the fuel pump assembly, that runs about $350. I've been using OBDFusion and a Veepeak Bluetooth OBD to monitor the fuel temps and they can vary between as low as 80F to 135F when driving and while parked. I was hoping someone else might be able to provide some normal reference values for comparisons sake. In park, if I bring the engine off idle to around 1500 RPM, fuel temps drop about 10F. This is a return-less fuel system, correct?

Thanks for any help!


leedos
Posts: 3
Joined: Fri May 24, 2019 4:55 pm
Car: 2010 G37s Sport Premium

Re: Code P0181 Fuel Temp Sensor range

Postby leedos » Mon Jun 10, 2019 8:05 am

To add to the above, the fuel temp sensor is reading over 150F when the car is cold started in the morning. This is triggering a "pending" fault code. Once the car is warmed up, the fuel temp readings slowly fall to within what I would consider a normal range. If the code is cleared, it will not come back until after the car has cooled down overnight. After some additional part research it seems I can buy the fuel level sensor assembly and it seem to come with the temp sensor. Since this may be an electrical problem and not a sensor problem I'm going hold of on replacing the sensors. Ordered some electrical contact cleaner to see if it might be the connect to the fuel pump assembly. Not hopeful there, but I needed to by some electrical contact cleaner anyways.

leedos
Posts: 3
Joined: Fri May 24, 2019 4:55 pm
Car: 2010 G37s Sport Premium

Re: Code P0181 Fuel Temp Sensor range

Postby leedos » Tue Aug 13, 2019 10:39 pm

Fixed. I pulled the fuel pump and the temp sensor tested OK when checked with an ohm meter. 1700K to 1900K ohms. After the harness tested OK, I tried replacing the combination meter, but the problem remained. I got some more time to diagnose the problem. The only thing left was the ECU. I pulled it and found two bent pins on the ECU connector responsible for powering the sensor. This also solved a problem with the power steering providing very low assist. Previous owner reported that both problems appeared after a mechanic worked on the car.

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