Limp mode

Hi folks,
I've had quite a few issues over the past year and am appreciative of the help I've gotten. My check engine light continues to come of from time to time and the "limp mode " also starts. I did a voltage check at the TPS connection before and decided to replace it to see if that would fix it. It did; temporarily everything worked but it has come back yet again to a lesser extent. Are their any other suggestion of the cause of this.?
My diagnostic abilities are at the beginner level but I'm learning.

 

Would do simplest stuff 1st......

Like check battery and maybe reseat the cables.

Check all the grounds. All this deteriorates over time.

Clean air filter and maybe clean the maf sensor

Then maybe look for vac leaks.......then exhaust


After that you're probably gonna need a scanner.....and someone knows how to use it

Knowing the cel code might help.....might not......wouldnt hurt to know.....


common are dirty maf.....and close 2nd is a vac or exhaust leak....



Only limp mode I've ever seen is if you unplug the maf.....some will go into an emergency closed loop

the maf and 1st O2 sensor runs the engine when running correctly

 

Viagra.

 

Code will be a great start...

 

I,ve had a code read done . It is P0505 idle air control system. Also alot of secondary codes concerning the throttle / position sensors. The issue seems to be electrical , as ive taken off the throttle body and cleaned it. The TPS is brand new. Any thoughts O,silver taco? Thanks for any help i getco

 

Have you replaced the idle control valve?

 

Im considering replacing the IAC, however these parts are expensive. So im trying to get it right rather than just replacing stuff

 

You can try cleaning it, they can stick.

 

Hi again, dealing w the same issue posted above. I had the truck diagnosed at a reputable shop ,he said i needed a new throttle body, job was estimated at 1K ,so i declined. He said it would randomly change voltage, from the signal wire i think. It has a new TPS already so i replaced the throttle accelerator cable body . Those are the only 2 electronic parts in this type throttle body. Could it be anything else? Should i just replace the entire throttle body? Thanks for your comments.

 

The signal that would randomly change voltage - was it your throttle or your pedal position sensor? (it's DBW right?)

 

Hmm. The TB has nothing to do with voltage. The TPS was changed so if it's functioning properly changing the TB won't do anything. Now if the TB has abnormal wear that could be a reason to replace it, but I would be highly skeptical that a new TB will change anything. Did he give you any additional details?

 

I changed out the TB electronic accel cable part. Had to get on Amazon bc none of stores could get it.0but so far it is wworking, no more check engine light! Appreciate the help.

 

The 2003 does not have a traditional cable actuated throttle? Wasn't aware.

 

yeah if you have the 03/04 TB its different than all rest of us....

they have an extra sensor......
https://www.tacomaworld.com/threads...-2-3-to-the-floor.848229/page-2#post-30326123


And the TB has an internal motor that can go bad....
https://www.tacomaworld.com/threads...-2-3-to-the-floor.848229/page-2#post-30333994


'TPS,throttle body and motor must come together as one unit'

22030-62020 Genuine Toyota Throttle Body Assembly W/Motor

 

Interesting. I like the cable. The simplicity of my truck is a bonus to me. Hand crank windows and all.

 

The simplicity of just the cable is way more of a bonus than you know.

 

Oh I know, I have modern cars...meh.

 

I was just referring to one less headache to worry about for those prior years.

 

Oh I got ya. And yes, absolutely, that looks like it could get expensive for sure.