Engine loses power for a split second every morning

big hand syndrome. Have the dealer check the throttle position sensor on the gas pedal.

 

that's what the falls flat on it's face problem was called in the old'n day's of Prius owner ship. There is a sensor on the gas pedal that determins the amount of throttle opening you want. And when they fail the car flat spots on acceleration. It's fairly expensive to replace (just giving you a heads up) so have it properly inspected if this is the case.

 

If your dealer can pull out the DTC (Diagnostic Trouble Code), P1120, then it is probably the Accelerator Pedal Assembly (part# 78010–47030). (Technical Service Bulletin EG018-02).

Vincent

 

Sorry covered only for 36k miles, or under Toyota's extended warranty if it had been purchased by that same deadline.

If the assembly is replaced, please ask to retain the old one. I would like to purchase a failed one to determine if it can be made well by cleaning the potentiometers.

But for whatever it's worth this does not sound like big hand to me. A diagnostic code check is definitely in prder.

DAS, 74k miles on a 2001, no big hand yet

 

As what DAS has said, the TSB only covers 36 months or 36k miles.

But I think it also depends on your dealer. One owner got lucky and got it replaced FOC.

Replaced accelerator pedal (2001 Prius)

Vincent

 

You mentioned that the DTC did not appear on your dealer's computer so it may not be the accelerator pedal assembly afterall. But I could be wrong.

It seems that your problem only happens during cold start. Next time, maybe you can observe the "Low coolant temperature indicator light (in blue)" on the instrument cluster. Does it happened before, during or after the indicator lights off?

Vincent

 

unless it sets the MIL I doubt that the code would be saved. If you really want to find the code just hold the gas pedal at the spot where it sags and keep it there till the ICE quits. That will set the MIL and the code will be stored for at least several restarts. If you can do this and set the MIL take it to your dealer as soon as possible and tell them the Check Engine Light is on (CEL=MIL) The dealer will understand and the tech will be able to pull it with the THHT.

 

As I have posted elsewhere, OldManJimbo kindly send me his failed accelerator pedal assembly (APA), and I did things to it. It is currently in my 2001 Prius and operaing correctly for 350 miles so far.

But I have seen other posts which challenge my understanding of the entire Big Hand Syndrome. Already established is that if you have symptoms, a VIN before the cutoff, and DTC P1120 (with info codes 104-114), you get a new APA under EG018-02, during the first 36k miles, 36 months.

However with an intermittent loss of power at highway speeds, not accompanied by any DTCs, the tech is supposed to notice TSB EG006-1. This offers replacement of the HV ECU for 100k miles (with no reference to the APA).

I have privately emailed OldManJimbo, asking him to look into this. But it may rasie the possibility that his APA was not originally at fault.

Can anyone comment? As I am trying to understand how (if possible) to recondition a failed APA, it is important to know if the patient I operated upon was in fact healthy to begin with.