elkootcho Posted April 15, 2014 Share Posted April 15, 2014 2000 Pathfinder SE My check engine light has been on for a while giving me an O2 sensor code. I swapped that out and reset the light in order to get the car smogged. The light remained off for several weeks. Car failed smog but showed timing to be at 21. Today I removed the Throttle Position Sensor and adjusted the timing to 15. As I was reinstalling the TPS the plastic cracked as it seemed to become very brittle over time. Car immediately threw P0120 (- Faulty Throttle Position Sensor, - Throttle Position Sensor circuit is open or shorted, - Throttle Position Sensor poor electrical connection I purchased a new TPS at autozone and cleared the code. Light immediately came back on. The car now has a rough hesitation at low RPM and very little power. If I floor the gas pedal the RPM to doesn't jump into the red and acceleration is very sluggish. Any ideas? Link to comment Share on other sites More sharing options...
elkootcho Posted April 15, 2014 Author Share Posted April 15, 2014 Also, pathfinder wants to stall on initial start up (never had this problem until now). I touch of gas and it idles. Link to comment Share on other sites More sharing options...
Precise1 Posted April 15, 2014 Share Posted April 15, 2014 The TPS needs to be adjusted (it puts out voltage depending on how open it is) Go to the Garage section and download a copy of the Factory Service Manual from the pinned thread. EC-143 shows all the diagnostic steps and EC-85 shows how to adjust it. I doubt anything is broken, just not set correctly... B Link to comment Share on other sites More sharing options...
elkootcho Posted April 16, 2014 Author Share Posted April 16, 2014 Thanks for the link. I assumed that the TPS was a simple bolt-on item. Here's were I remain confused: How do I RESET THROTTLE POSITION SENSOR IDLE POSITION MEMORY? The manual instructs on the usage of CONSULT (obviously, I ain't got that!). Link to comment Share on other sites More sharing options...
elkootcho Posted April 16, 2014 Author Share Posted April 16, 2014 found it on EC114 Link to comment Share on other sites More sharing options...
Precise1 Posted April 16, 2014 Share Posted April 16, 2014 The manual can be a little confusing and daunting, but most needed info is in there, somewhere... Let us know how it works out and what you learned. B Link to comment Share on other sites More sharing options...
elkootcho Posted April 16, 2014 Author Share Posted April 16, 2014 (edited) Looks like this is above my pay grade. Confused...to say the least. Anyone know an affordable Nissan mechanic in the Los Angeles area? Also, will pulling the neg battery terminal allow the computer to "relearn" the TPS position? I'm not sure if I'm doing it properly with the whole "key on, key off" thing. Edited April 16, 2014 by elkootcho Link to comment Share on other sites More sharing options...
Precise1 Posted April 16, 2014 Share Posted April 16, 2014 Ok, so it says to check the continuity of the closed throttle postion sensor with that and the TSP disconnected and after revving the engine. Then warm up the motor with them disconnected, and shut off the motor. Reconnect both harness connectors, turn ignition switch to on, turn ignition switch to off and wait for at least 5 seconds, and repeat this 20 times. Is that what you are doing? TSP values: Warmed up, engine off with ignition on with throttle valve fully closed .3-.7 volts, with throttle valve fully open aprox 4 volts. Is this what you are getting? What part exactly are you hung up on? I understand if you want to take it to a mechanic, at least having identified the item so they aren't troubleshooting, just setting/repairing. theexbrit, cman and karmann all live down in that mess and might have some leads for a mechanic... B Link to comment Share on other sites More sharing options...
adamzan Posted April 16, 2014 Share Posted April 16, 2014 To me it sounds like you moved the timing too far back...Are you sure you're reading the marks on the pulley correctly? Link to comment Share on other sites More sharing options...
elkootcho Posted April 17, 2014 Author Share Posted April 17, 2014 To me it sounds like you moved the timing too far back...Are you sure you're reading the marks on the pulley correctly? I think so, I checked multiple times and the pointer is right at the second notch from the right. Link to comment Share on other sites More sharing options...
elkootcho Posted April 17, 2014 Author Share Posted April 17, 2014 Ok, so it says to check the continuity of the closed throttle postion sensor with that and the TSP disconnected and after revving the engine. Then warm up the motor with them disconnected, and shut off the motor. Reconnect both harness connectors, turn ignition switch to on, turn ignition switch to off and wait for at least 5 seconds, and repeat this 20 times. Is that what you are doing? TSP values: Warmed up, engine off with ignition on with throttle valve fully closed .3-.7 volts, with throttle valve fully open aprox 4 volts. Is this what you are getting? What part exactly are you hung up on? I understand if you want to take it to a mechanic, at least having identified the item so they aren't troubleshooting, just setting/repairing. theexbrit, cman and karmann all live down in that mess and might have some leads for a mechanic... B Thanks for the help. I'm going to give it another shot, starting from scratch. What setting should my multimeter be on for all these readings? Link to comment Share on other sites More sharing options...
Precise1 Posted April 17, 2014 Share Posted April 17, 2014 Resistance is Ohms, and the voltage is VDC, Volts Direct Current. 12 volts... B Link to comment Share on other sites More sharing options...
elkootcho Posted April 18, 2014 Author Share Posted April 18, 2014 (edited) Update: I got a reading of .4 with the throttle fully closed. Fully open: .4 (no change) This made me look at the simple mechanics of what was going on and the answer was embarassingly simple. When I install the new TPS the tab on the inside was not properly engaged with the throttle bar that would cause it to rotate upon acceleration. Stupid mistake. I reinstalled the TPS, rechecked with the multimeter and got readings of .5 up to about 4.12. I performed the key sequence ON 5 sec, OFF 10 sec (20 times), turned off the check engine light and took it for 2 laps around the block. The light did not come back on (previously, it would turn on as soon as I backed out of the driveway) and the transmission was out of fail-safe mode. Seems to be running much more smoothly than previously. Now, fingers crossed it passes smog next week. Precise1: thanks for the encouragement. I was ready to throw in the towel but took a step back and took a breath. For future knowledge, there is a very helpful step-by-step guide that I found here: http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/throttle-position-sensor-tests-1 Edited April 18, 2014 by elkootcho Link to comment Share on other sites More sharing options...
Precise1 Posted April 20, 2014 Share Posted April 20, 2014 I reinstalled the TPS, rechecked with the multimeter and got readings of .5 up to about 4.12. Precise1: thanks for the encouragement. I was ready to throw in the towel but took a step back and took a breath. Nice, those are pretty much the values the manual describes for proper function. You are welcome, I'm glad it was a simple fix. We've all missed things, gotten frustrated, needed another set of eyes, opinion, etc. A big key can be to walk away, cool off, start over and don't assume anything. It should pass as long as everything else is working properly, but make sure to drive it enough to prove the problem is gone and the ECU to 'relearn'. B Link to comment Share on other sites More sharing options...
elkootcho Posted May 13, 2014 Author Share Posted May 13, 2014 I wanted to close the thread by saying that the Pathfinder passed smog after I got the timing right and the TPS reinstalled correctly. Thank you again for the help. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now