Acceleration problem..Can duplicate with motor off.

To: Tony Ciccotelli: 2/3/20 Monday 3am **New to your forum so I don't know exactly how to reply to your email comments to my question. So I am leaving a comment as answer on the forum with a photo. By the way, I could not find your answer on the forum but I did get an email from you (2 of them). Thank you. Sorry I posted the same question twice since I thought I did not enter the first one correctly. ** You mentioned I should replace the lowest cost part to first replace if unsure of the actual culprit. You mentioned the PPS or Pedal Position sensor. as the possible problem. ** As I mentioned in my original question I did remove the pedal and measured the resistance of the 2 pots on the sensor versus Pedal Travel and plotted it on a graph (See attachment). The results agree quite dramatically (good correlation) (see photo in attachment) with a wonderful instructive video for everyone I found at YouTube Channel Toyota USA by Paul Williamson of Toyota University. titled: Safety Features of Electronic Throttle Systems (ETCS) Toyota. See this link : https://www.youtube.com/watch?v=jOaYGSU3boM I ** Strategy 1: Will go ahead and back-probe the PPS with ignition on, motor off to confirm actual operation. My only method is to back-probe the connector at this time very carefully. If I measure both sensor voltages proportionately rising with pedal travel while the Throttle Body vane does not move till 50% pedal travel is occurs then I can confirm the Throttle Body motor is the next problem assuming the motor output from the PCM computer is fine.. Do you agree with this strategy?. ** Strategy 2: If I decide to replace the Throttle Body, I priced a TB at Autozone by Durolast and it is $212 less 20% discount so would be one of aftermarket lowest cost solution or I or the OEM part for $356 online from toyotapartsdeal.com.or similar site. Probably not worth returning it if it does not solve the problem, but an option. MarioG - GuruPKPHX

To: Tony Ciccotelli: 2/3/20 Monday 3am **New to your forum so I don't know exactly how to reply to your email comments to my question. So I am leaving a comment as answer on the forum with a photo. By the way, I could not find your answer on the forum but I did get an email from you (2 of them). Thank you. Sorry I posted the same question twice since I thought I did not enter the first one correctly. ** You mentioned I should replace the lowest cost part to first replace if unsure of the actual culprit. You mentioned the PPS or Pedal Position sensor. as the possible problem. ** As I mentioned in my original question I did remove the pedal and measured the resistance of the 2 pots on the sensor versus Pedal Travel and plotted it on a graph (See attachment). The results agree quite dramatically (good correlation) (see photo in attachment) with a wonderful instructive video for everyone I found at YouTube Channel Toyota USA by Paul Williamson of Toyota University. titled: Safety Features of Electronic Throttle Systems (ETCS) Toyota. See this link : https://www.youtube.com/watch?v=jOaYGSU3boM I ** Strategy 1: Will go ahead and back-probe the PPS with ignition on, motor off to confirm actual operation. My only method is to back-probe the connector at this time very carefully. If I measure both sensor voltages proportionately rising with pedal travel while the Throttle Body vane does not move till 50% pedal travel is occurs then I can confirm the Throttle Body motor is the next problem assuming the motor output from the PCM computer is fine.. Do you agree with this strategy?. ** Strategy 2: If I decide to replace the Throttle Body, I priced a TB at Autozone by Durolast and it is $212 less 20% discount so would be one of aftermarket lowest cost solution or I or the OEM part for $356 online from toyotapartsdeal.com.or similar site. Probably not worth returning it if it does not solve the problem, but an option. MarioG - GuruPKPHX

Tony, Take a look at this good real world video I was able to locate. See how the Throttle Body butterfly Vane gets stuck at closed position. (later in the video he takes it apart and find out why it gets stuck.) My car is operating very similarly. Depress pedal. Nothing happens. I have to push to 50% to get acceleration. I can also can play with small pedal pressure with the accelerator to get some response and get normal acceleration. BUT in my 2006 Camry XLE car the following is different from that observed in the video: * I do not see it get stuck when I push it manually. * I get NO diagnostic trouble codes from the computer when I use my Scan tool. * I do not get a Check Engine LIght or Malfunction Illumination LIght (the official term) Video: https://www.youtube.com/watch?v=-oIFyvBpr_U Mario G. GuruPkPhx

Tony: Thanks for your follow up reminders as to my status with my acceleration problem with my 2006 Camry XLE with 65000 miles with new battery, fluids checked, Throttle body and MAF cleaned. I have been composing a reply to you for many days but could never complete it to my satisfaction, Measurements (Overview, Detail on my next post): I used my Digital Multimeter and INNOVA OBD2 3160b scanner to run voltage measurements (back-probing pins) on the Throttle Body sensor 94 pins) , Motor M+ and M- pins (2) (voltage to ground and differentially, and also of the 6 pin Accelerator Pedal. It was that information I was tryging to post. The Innova Scanner was able to show me the TPS% Throttle body Sensor output as the pedal was depressed and was niche and smooth with no drops. I could see the failure modes and see that the TPS% would not change from 0% to 50% pedal travel and as you increased further it would start to increase normally. I also recorded the live data which was interesting. All my measurement looked great on 2/2/20 of the Pedal and Throttle Body Sensor and Motor Pins. But still I had the 50% pedal acceleration problem (started to accelerate normally at 50% pedal travel) and also still had the 10% play failure mode (play with pedal at 10% travel and would start to accelerate normally. Remember no DTC codes, Engine running fine. Driving Test: So on 2/2/20 late at night I took car for a driving test to see if all was still working the same way and to check out the failing modes and see if I could learn something new. . Lo and behold, i discovered that if I hold the pedal at 5% travel or greater and never release it while braking with my left foot at stop signs and lights, that the car would never fail and would operate perfectly like a new car. I have other things to do so I decided to think over what is my next step. I had gotten quotes on replacing the Throttle Body/Sensor (Sensor is not serviceable, attached with rivets), Accelerator Sensor (2 screws) and Accelerator Assembly. I was still not convinced replacing them would solve the problem, as I see many cases on the Internet that replacing those parts did not solve an engine hesitation problem. Once I got out of the failure modes a I described above, my engine would run fine with no hesitation.. Driving Test #2: I took it out for a spin driving test again on 2/12 and this time I discovered that If you only depress the Accelerator pedal a minuscule (very small() the car would never fail again, but I you release even for a microsecond (repeatable), the failure comes back. This was another discovery. When I measured earlier the Resistance of the Pedal Sensor (VPA and VPA2), I did not see anything abnormal, no drops, erratic readings. I even with Ignition on, motor off, increased pedal voltage reading in hundredths of a volt (0.01) and same everything smooth. All this confirmed my feeling the Throttle Body and Pedal were fine. Was the computer (ECM / PWM) failing at low voltage levels from the pedal? Did lots of research on the Internet studying the circuits (H-Bridge motor control, Electronic control system operation etc. Adjusting Pedal Sensor Idea: Brainstorming myself, I then remembered Saturday morning 2/15/20 that the Pedal Assembly had 2 screws holding the Sensor (Sensor Toyota 78030-33022, Pedal Assembly 78010-33010) and that the screw hole was a slot, not round. Could the solution to my problem was to make a simple adjustment of the sensor so it would increase the voltage reading to the computer at the 0% travel or released state? I researched the internet for information on the adjustment of the sensor but found none. I also found notes that it is recommend to replace the whole assembly and not the sensor itself for some strange reason. Last night I adjusted the pedal sensor screw position by shifting the sensor about 3/32 inch. The Actual travel of the sensor from release point to full travel is 105 Degrees. My adjustment only reduced that by several degrees. I also found out when testing with Ignition on, motor off, even at idle RPM the pedal had additional travel to get to the release state. Acceleration problem fixed: I am happy to report that my car is now running perfect like it has for 65000 miles. I cannot explain what happened to create my failure condition. Maybe the Computer input thresholds for reading the voltage from the pedal (It calculates the ratio of VPA2/VPA and reads voltage levels for detecting Fail/Safe/ Limp modes) changed at the released state and sent the computer into a strange state which did not trigger ever any DTC codes.. I found the pedal sensor adjustment screws tight and not loose. The pedal resistance values of the sensor at the released state also could have changed as well, but all looked fine from my measurement. My plotted resistance on graph paper looked identical to voltage graphs I found at the Toyota USA YouTube channel. (see my earlier post). That's it for now. I hope my troubleshooting process is interesting to others. I will post my measurement for the Throttle Body and Pedal in a separate post as I think your readers would benefit from my readings with a simple DMM of the Throttle Sensors, Motor inputs, and Pedal sensor. Mario GuruPKPHX

Status 2/19/20: I posted yesterday 2/18/20 how I solved my Acceleration problem for zeros cost after back-probing and taking measurement over a 36 day period of the Throttle Body sensor and motor and the Accelerator Pedal and doing heavy research of the Electronic Control System. My simple solution was to rotate the Accelerator Pedal Sensor on the pedal assembly by 3/32 inch.so it provided a higher 0% travel voltage to the ECU/PCM computer. Pedal rotation from released state to Full Throttle is about 100 degrees so I only reduced it by a few degrees. Today I drove the car for many hours and had no problems. Attached is a collage photo of the Pedal components showing the 2 screws used to adjust the sensor. Great feeling to get this solved.without installing a new Throttle body or Accelerator pedal. Mario - GuruPKPHX