How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask AutoTech08 Your Own Question
AutoTech08
AutoTech08, Workshop owner
Category: Nissan
Satisfied Customers: 973
Experience:  Diploma in Automotive Engineering, 30 years working experience.
12605055
Type Your Nissan Question Here...
AutoTech08 is online now
A new question is answered every 9 seconds

2001 frontier: crew cab..3.3l v-6..obd-II

This answer was rated:

2001 frontier crew cab with 3.3l v-6. Idle was high for a few days @ 1000 rpm, obd-II po510 tps sensor problem. sensor was replaced. Immediately after replacing sensor, rpm now 1100, obd-II now reads po120 pedal sensor failure & every time it goes into 2nd gear it down shifts to 1st...revs up to 3000 rpm, then goes back into 2nd gear before continuing normally.

Hi there,

 

DTC P0510: CLOSED THROTTLE POSITION (TP) SWITCH

 

DTC P0120: THROTTLE POSITION (TP) SENSOR

 

When installing the TPS, it has to be adjusted correctly failing which it would cause the code to show.

 

1. Check Base Idle Speed

Check idle speed. Base idle speed should be 650-750 RPM with transmission in Park or Neutral. If idle speed is as specified, go to next step. If idle speed is not as specified, adjust by turning idle speed adjusting screw. See Fig. 16 . Go to next step.

 

graphic

 

 

2. Check Closed TP Switch Idle Position

Turn ignition off. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect TP switch harness connector. See Fig. 17 . Insert a .012" (.30 mm) feeler gauge between throttle adjusting screw and stopper. See Fig. 18 .

 

graphic

 

graphic

 

3. Check continuity between TP switch terminals No. 4 and 5. See Fig. 17 . Continuity should exist. Remove .012" (.30 mm) feeler gauge, and insert .016" (.40 mm) feeler gauge. Continuity should not exist. If continuity is as specified, go to step 6. If continuity is not as specified, go to next step.

 

4. TP Sensor Idle Position Adjustment

Ensure engine is at normal operating temperature. Loosen TP sensor bolts. Remove .016" (.40 mm) feeler gauge, and insert .014" (.35 mm) feeler gauge. Open and close throttle. Continuity should not exist while closing throttle. If continuity exists, turn TP sensor body clockwise until continuity does not exist.

5. Remove .014" (.35 mm) feeler gauge, and insert .012" (.30 mm) feeler gauge. Slowly rotate TP sensor body counterclockwise until continuity exists, then tighten TP sensor bolts. Ensure continuity exists when throttle is closed and does not exist when throttle is open. Repeat 2 or 3 times. Remove .012" (.30 mm) feeler gauge, and insert .016" (.40 mm) feeler gauge. Ensure continuity does not exist when throttle is closed. Repeat 2 or 3 times. Go to next step.

 

6. Reset TP Sensor Idle Position Memory

Remove feeler gauge. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Turn ignition off. Turn ignition on, wait at least 5 seconds, then turn ignition off and wait at least 5 seconds. Repeat 20 times. Go to next step.

 

7. Check Target Idle Speed

Check idle speed. Target idle speed should be 700-800 RPM with transmission in Park or Neutral. If idle speed is as specified, go to next step. If idle speed is not as specified, adjust by turning idle speed adjusting screw. See Fig. 16 . Go to next step.

 

8. Clear DTC Memory

DTCs may be stored in ECM and/or Transmission Control Module (TCM) from performing basic inspection. Clear DTCs from ECM and TCM.

 

 

Customer: replied 7 years ago.
I followed the procedures to the point of " Reset TP Sensor Idle Position Memory" because no matter how far I turned the sensor either way to adjust it...the continuity would not turn off as described in the tps adjustment procedure. Tester is a brand new, computer safe continuity tester I bought at Advanced Auto Parts. So the idle speed is now adjusted, the obd-II still reads PO120, pedal position sensor malfunction, and the transmission still downshifts on it's own in 2nd gear. Any more suggestions? Again, the TP sensor is new and has the same hitachi numbers as the original.

While installing TP sensor, did you check the positioning of the pin?

 

I would suggest removing the TP sensor and reinstall, noting the mating marks. If this does not solve the problem, you have a bad TP sensor.

 

 

AutoTech08 and 4 other Nissan Specialists are ready to help you
Customer: replied 7 years ago.
I anticipated the mating problem when I installed it. I'm leaning towards a bad sensor and had the parts store order another one. I try it again in the morning. Thanx.