Throttle position sensor & check engine light

[J30inthe sun]

Just came back from Autozone, the scanner showed codes P0120, P0732 & P0733.

A couple of questions.

1 - Where is the throttle position sensor located?

2 - Infiniti Parts USA list it at $91.39. Any thoughts about going aftermarket? They are as cheap as $50 - $60 locally here:

http://www.autozone.com/R,2076...l.htm

http://www.partsamerica.com/Pr...Set=A

Lastly I found this: "Check-engine light: The check-engine light may come on and indicate a transmission problem. This is due to a faulty throttle position sensor. (1996-97)" :

http://consumerguideauto.howst...6.htm

Does anyone think the throttle sensor is the only problem?

Thanks in advance.

[GerryO]

Here's a photo of a TPS. Notice the strand of copper wire inserted into the rear of the connector (middle/white wire terminal) for the purpose of measuring output voltage.

What symptoms/problem prompted you to pull codes to begin with?

[J30inthe sun]

Here's a photo of a TPS. Notice the strand of copper wire inserted into the rear of the connector (middle/white wire terminal) for the purpose of measuring output voltage.

What symptoms/problem prompted you to pull codes to begin with?

Thanks for that picture!

The check engine light was on & the idle has been fluctuating to as high as 1200 rpms in park with the AC on, however it seems after driving for about 15 minutes it settles to @800 rpms.

What is the proper voltage reading for the wire inserted into the rear of the connector?

Any thoughts on aftermarket versus Infiniti for a new sensor?

[GerryO]

Thanks for that picture!

The check engine light was on & the idle has been fluctuating to as high as 1200 rpms in park with the AC on, however it seems after driving for about 15 minutes it settles to @800 rpms.

What is the proper voltage reading for the wire inserted into the rear of the connector?

Any thoughts on aftermarket versus Infiniti for a new sensor?

The idle speed is higher in Park than it is with the car in gear and your foot on the brake. My idle speed drops at two temperature dependent times; first, soon after start-up and later when the engine is almost fully warmed up and idling when at a full stop. 800 rpms when fully warmed up and in Park sounds correct.

The voltage reading to ground should be 0.40 to 0.45 VDC, measured with the engine running at idle. Higher readings will increase the idle speed and delay the shift points. Lower readings will lower the idle speed to a point and will also make the transmission over-sensitive to foot pressure on the pedal to the point of causing hunting and higher engine rpms at crusing speeds.

If you make changes in the voltage you must immediately afterward momentarily disconnect the grey connector with the engine running in order to clear the old and register the new "Throttle Closed" voltage in the ECM.

I haven't ever replaced my TPS, but it's probably a good thing to do after a 15 years, as they also have upper and lower resistance values that can be checked. Maybe they can be cleaned with contact cleaner and it would also be a good idea to make sure that all of the connections to the TPS are good and covered with dielectric grease.

[J30inthe sun]

Unfortunately my sesnor on the 97 J looks like this:http://www.autopartswarehouse.....html

Also the plugs into the sensor run directly into the wiring harness, there is not any plug to insert the copper wire for testing.

Any thougths?

[J30inthe sun]

2 - Infiniti Parts USA list it at $91.39. Any thoughts about going aftermarket? They are as cheap as $50 - $60 locally

I just wanted to let everyone know I went to Pep Boys & picked up the TPS for $42.99 + tax. The box says Borg Warner but the TSP is made by Hitachi the exact same as the original equipment that came with the car & has exactly the same parts #s on it.

Good luck if you need one with Pep Boys.