Reviving my 2001 PRIUS

Isnt that a pedal issue?
replace sensor only in 2001 pedal? | PriusChat

You can stick ohm meter with small alligator clips on the dual potentiometers down there.

If you search the forums for the whisker problem, it might be worth trying to just slap a 9V across the wiper and one side the VC pin to burn up any whiskers. 9V across that much resistance for a moment won't be more than a few milliamps which is all that is needed to burn whiskers, so alligator clips hook to 9V, move pedal a few times apply to second wiper.

 

Which bracket? This one. That vacuum sensor in the picture is for HCAC. I believe the other vacuum sensor is same MAP type and uses three pin connector, VC, gnd, and signal. So probably not a ground issue (is it 2 wire?)

 

If you read that entire thread, that bracket and all that vacuum stuff is for the HCAC (flow valve in exhaust). It is 3 wire, I just told you what the three wires are and what the sensor is for, that vacuum sensor is on the other side of a check valve and a vacuum switch (VSV). It would only throw a P1436 code and there is no ground in that bracket, all the sensors have all the wires they need. There is another vacuum sensor for other vacuum problems that code might throw.

I would examine the pedal first, as that is most likely. There are other air lines connected to the throttle body, so there might be a leak, but that bracket and HCAC stuff is not involved... Did you check under the car to see if the vacuum line came off the HCAC diaphragm actuator?

 

The problem is the resistance changes. So if you put the accelerator in a fixture so you can change the angle, plot the resistance changes. If bad, the resistance will drift at each angular offset. Doug Schafer used a 9V battery and a small speaker to hear the problem.

There are three solutions:

• $500 accelerator replacement - a Toyota part, expensive but available. Possibly cheaper from salvage
• Rebuild accelerator - using a Dremel tool, remove the cover; clean the contacts and surfaces, and; reassemble using JB Weld or equivalent epoxy.
• Burn-out whiskers (experimental) - use a 12V wall-wart to burn-out any tin whiskers. Experimental because I was able to verify the resistance characteristics changed. However, I sent my inventory to some other folks who are testing the tin whisker hypothesis with more precise instrumentation.

Bob Wilson

 

I believe a 9V alone just placed across the wiper (pin 5 +9V to - on pin 1) and moving the pedal will do it.

18 mA to 3.6mA and all under 1/4watt. Mostly just for the convenience. 9V can put out enough current to do the job.

 

I can never find a good 9V battery so I tend to use wal-warts. <grins>

Bob Wilson

 

Actually your pedal is probably ok unless it reacts funny when driving.

P1437 is probably vacuum related, not sure why google failed there and brought up the pedal thread. Did you check the hose connected to the valve on the exhaust? You can also rent a hand brake pump from an auto parts place and draw a vacuum on the hose and see if it holds (at least for the HCAC line)

 

This might interest you enough to avoid cheapos. Also they have the lithium 9V now for ridiculous amounts.
Discharge tests and capacity measurement of 9 volt transistor radio
batteries