2003, Tacoma, V6, Auto, S/C, 7th and all that . . . I was driving down the freeway and every now and then it is like I took my foot off the gas – but I didn’t! If I step on it, it is fine. I used to think my foot had just slipped sometimes! Very intermittent. It did it a few time months ago a lot but went away and then this past weekend, it did it every few minutes until it stuck that way. The truck still goes, can do freeway speeds, but there is considerable play in the gas petal and can’t floor it (even when floored).
So I clean the throttle body and check everything. Still the same. I compare this to another Tacoma. If both are running and one grabs the throttle linkage at the Accelerator Pedal Position Sensor (front of Throttle Body) and turn it counter clockwise, a good V6 will rev with nearly zero play while mine twists about 15 degrees or more before anything happens, the same as the play in the petal.
Though it threw a Check Engine Light when throttle response went away it went out on its own before I could hook up the ODBII reader and get the code and has not come back.
So I start the diagnostics in the Toyota Manual (at SF-28). Linkage OK, with ignition on I can hear the Throttle Control Motor, The Throttle Opening Percentage goes to 60% but not much more, Idle is good . . . The Throttle Control Motor’s motor resistance is in range but the clutch is 5.3 ohms (range is 4.2 to 5.2). However, the temp was above 68 degrees as they list for measurement for the above range to be valid. Both the Accelerator Pedal Position Sensor and the Throttle Position Sensor read in range and checking the other pins, they seem to change resistance smoothly (but I do not know if the ranges are right as I do not have a min and max resistance spec for the extremes of these potentiometers).
If I take the Accelerator Pedal Position Sensor off but leave it connected and the ignition turned on and turn the sensor, the Throttle Control Motor clutch does not immediately engage (but I can hear it click) and reflect the movements of the Accelerator Pedal Position Sensor. The 15 degree or so gap is there. If I move the Accelerator Pedal Position Sensor back and forth, there are times that the Throttle Body responds slowly as well.
So, is the Accelerator Pedal Position Sensor bad (increased potentiometer resistance) and not letting the ECU know I am stepping on the gas until it has moved. Is the Throttle Control Motor or its clutch failing? Anything else?
So I clean the throttle body and check everything. Still the same. I compare this to another Tacoma. If both are running and one grabs the throttle linkage at the Accelerator Pedal Position Sensor (front of Throttle Body) and turn it counter clockwise, a good V6 will rev with nearly zero play while mine twists about 15 degrees or more before anything happens, the same as the play in the petal.
Though it threw a Check Engine Light when throttle response went away it went out on its own before I could hook up the ODBII reader and get the code and has not come back.
So I start the diagnostics in the Toyota Manual (at SF-28). Linkage OK, with ignition on I can hear the Throttle Control Motor, The Throttle Opening Percentage goes to 60% but not much more, Idle is good . . . The Throttle Control Motor’s motor resistance is in range but the clutch is 5.3 ohms (range is 4.2 to 5.2). However, the temp was above 68 degrees as they list for measurement for the above range to be valid. Both the Accelerator Pedal Position Sensor and the Throttle Position Sensor read in range and checking the other pins, they seem to change resistance smoothly (but I do not know if the ranges are right as I do not have a min and max resistance spec for the extremes of these potentiometers).
If I take the Accelerator Pedal Position Sensor off but leave it connected and the ignition turned on and turn the sensor, the Throttle Control Motor clutch does not immediately engage (but I can hear it click) and reflect the movements of the Accelerator Pedal Position Sensor. The 15 degree or so gap is there. If I move the Accelerator Pedal Position Sensor back and forth, there are times that the Throttle Body responds slowly as well.
So, is the Accelerator Pedal Position Sensor bad (increased potentiometer resistance) and not letting the ECU know I am stepping on the gas until it has moved. Is the Throttle Control Motor or its clutch failing? Anything else?