2001 and 2002 Are NOT Drive By Wire

Tyler James Inc

Tyler James Inc

Senior Member
Bold statement? Maybe.
For the past few years, I've heard "'01/'02 are DBW".
I got an '01, and saw a throttle cable. "Wtf? That's not DBW..."
I've also heard a couple people say "the cable is just a back-up, and doesn't open the butterfly all the way"
What? I've had plenty of DBW rigs, and none have had any kind of "back-up/limp-home" cable.
I also verified my cable DOES open my butterfly 100%, and there is no kind of rheostat on the throttle pedal- this is not a DBW vehicle.
However, there is a motor on the back of the TB that the cruise uses to keep/regulate the throttle open.

Anyone know where the info came from that claimed these are throttle/drive by wire? It's false.
 
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Tyler James Inc said:
Bold statement? Maybe.
For the past few years, I've heard "'01/'02 are DBW".
I got an '01, and saw a throttle cable. "Wtf? That's not DBW..."
I've also heard a couple people say "the cable is just a back-up, and doesn't open the butterfly all the way"
What? I've had plenty of DBW rigs, and none have had any kind of "back-up/limp-home" cable.
I also verified my cable DOES open my butterfly 100%, and there is no kind of rheostat on the throttle pedal- this is not a DBW vehicle.
However, there is a motor on the back of the TB that the cruise uses to keep/regulate the throttle open.

Anyone know where the info came from that claimed these are throttle/drive by wire? It's false.
Click to expand...

Its drive by wire assisted by cable. So if ETCS-i failes it will still work. ETCS-i (Electronic Throttle Control System-intelligent) is what toyota calls it.

The cable opens throttle body but throttle is controlled electronically. Throttle response is night and day better on the 2001+.
 
When the system is working correctly (key ON, throttle motor working) the cable connection on the throttle body is not connected directly to the throttle plate. There is a disconnect clutch that removes the direct throttle cable to throttle plate connection, allowing the ECU to read the requested throttle position while controlling the throttle position separately. It is DBW in that sense, but there is back up throttle control by the cable. This comes from a time where the NHTSA wasn't comfortable with a true full DBW system. As implemented through, the ECU has full control over the throttle position in normal driving situations...

-Charlie

Edit: Ooooo... may have spoke to soon, based on the ETCS-i comment above. See the attached file. Maybe on the 4Runner only the 'extra' throttle motor is used for cruise control...
 

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phattyduck said:
When the system is working correctly (key ON, throttle motor working) the cable connection on the throttle body is not connected directly to the throttle plate. There is a disconnect clutch that removes the direct throttle cable to throttle plate connection, allowing the ECU to read the requested throttle position while controlling the throttle position separately. It is DBW in that sense, but there is back up throttle control by the cable. This comes from a time where the NHTSA wasn't comfortable with a true full DBW system. As implemented through, the ECU has full control over the throttle position in normal driving situations...

-Charlie
Click to expand...

GOod info. I think they added it for VSC. It needs DBW to deactivate the throttle when VSC activates.
 
phattyduck said:
Ooooo... may have spoke to soon, based on the ETCS-i comment above. See the attached file. Maybe on the 4Runner only the 'extra' throttle motor is used for cruise control...
Click to expand...

Haha that's what I said in my first post; it's only for the cruise. With no electronic devices on the throttle pedal, how does the TB open? Maybe it's telepathy [emoji317]

Throttle response might be night and day, but it's because of something other than the non-existent DBW system [emoji6]

I'm honestly just wondering where all this info- that's been getting tossed around for years- came from. How has no one looked at the throttle pedal of an '01/'02 before me and said "oh hey, that pedal couldn't get any more simple, and it clearly has no electronics on it"?

Charlie, I had to go to a different app to see that PDF. The thing is, my pedal has no "throttle position sensor" as shown.
 
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Drive by wire

Tyler James Inc said:
Haha that's what I said in my first post; it's only for the cruise. With no electronic devices on the throttle pedal, how does the TB open? Maybe it's telepathy [emoji317]

Throttle response might be night and day, but it's because of something other than the non-existent DBW system [emoji6]

I'm honestly just wondering where all this info- that's been getting tossed around for years- came from. How has no one looked at the throttle pedal of an '01/'02 before me and said "oh hey, that pedal couldn't get any more simple, and it clearly has no electronics on it"?

Charlie, I had to go to a different app to see that PDF. The thing is, my pedal has no "throttle position sensor" as shown.
Click to expand...

I guarantee you have to have a ECM from a 2003-2004 Tacoma for our 01-02 4Runners to work correctly with the 5 Speed swap. Our throttle bodies are def. drive by wire with cable back up. I originally purchased a 2002 Tacoma M/T 5 speed ECM and there will CEL's related to the driveby wire and the throttle would not operate correctly. It would rev the motor buy only with throttle travel went to the point where the cable grabbed the butterfly. When I swapped my 02 4Runner ECM back in those CEL's went away and the missing A/T CEL's returned. Then I sourced a 2004 Tacoma M/T 5 Speed ECM plugged it in and all was good. No CEL's. I can send you my 02 Tacoma ECM and you can try it for yourself.
 
anniesball72 said:
I guarantee you have to have a ECM from a 2003-2004 Tacoma for our 01-02 4Runners to work correctly with a 5-speed...
Click to expand...

Yeah, the '01/'02 definitely have differences in engine control. I'm not talking about 5-speed swapping or ECM compatibility. I already have an '03 M/T 3.4 4WD Tacoma ECU-
099abc38f7e947f04371111db7eb423a.jpg

But that's irrelevant.
Regardless of engine control, my 2001 4Runner is absolutely not DBW.
 
[MENTION=133074]anniesball72[/MENTION]
Take the cable from your pedal off at your TB and report back what happens when you push the pedal.
 
Tyler James Inc said:
Haha that's what I said in my first post; it's only for the cruise. With no electronic devices on the throttle pedal, how does the TB open? Maybe it's telepathy [emoji317]

Throttle response might be night and day, but it's because of something other than the non-existent DBW system [emoji6]

I'm honestly just wondering where all this info- that's been getting tossed around for years- came from. How has no one looked at the throttle pedal of an '01/'02 before me and said "oh hey, that pedal couldn't get any more simple, and it clearly has no electronics on it"?

Charlie, I had to go to a different app to see that PDF. The thing is, my pedal has no "throttle position sensor" as shown.
Click to expand...

So how does VSC completely dethrottle the motor if its not electronically controlled. I just know what I have read also since I own an older one.
 
I guess they aren't true "drive by wire", but instead probably have some sort of electronics in the throttle body that send information to the ECU and injectors or so to increase pedal response and make the engine run smoother.

Disconnecting the throttle cable from the throttle body on my 01 makes the gas pedal useless. The pedal is connected to the throttle body by only the cable.
 
According to the FSM throttle position sensor is at the throttle body where accelerator cable attaches it has a plug connector.
 
JayRolla said:
So how does VSC completely dethrottle the motor if its not electronically controlled. I just know what I have read also since I own an older one.
Click to expand...

I wonder this too. Maybe it just doesn't send the gas to the injectors or something? Seems like it could be overridden since there is a manual connection.

From the 2001 Toyota 4Runner brochure:
 

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96RedRunner said:
Cruise motor on firewall side of TB, accelerator pedal position sensor on radiator side. How it is on my 01
Click to expand...

I feel like this is the answer. The cable is not directly linked to the throttle body butterfly valve, but to a sensor that is on the throttle body which then controls the butterfly valve. That's why disconnecting the throttle cable disconnects the gas pedal, it is depriving the sensor of the input to control the butterfly valve.
 
[MENTION=50342]JayRolla[/MENTION] I'm not sure. Maybe there is a spring on the throttle cable cam/pulley/whateveryouwannacallit that the motor on the back of the TB can overpower?
I'll have to play with it more once I get it running again.
 
Tyler James Inc said:
[MENTION=50342]JayRolla[/MENTION] I'm not sure. Maybe there is a spring on the throttle cable cam/pulley/whateveryouwannacallit that the motor on the back of the TB can overpower?
I'll have to play with it more once I get it running again.
Click to expand...

Yes there is a spring where you connect thottle cable, you see it when you look at TB. There is a black plastic case so to speak where you plug harness in. I'm thinking a reostat/encoder type position sensor is used.
 
96RedRunner said:
Yes there is a spring where you connect thottle cable, you see it when you look at TB. There is a black plastic case so to speak where you plug harness in. I'm thinking a reostat/encoder type position sensor is used.
Click to expand...
Yeah, I just looked at/played with mine too. The spring you can see is just a return spring.
Unner said:
I feel like this is the answer. The cable is not directly linked to the throttle body butterfly valve, but to a sensor that is on the throttle body which then controls the butterfly valve. That's why disconnecting the throttle cable disconnects the gas pedal, it is depriving the sensor of the input to control the butterfly valve.
Click to expand...
I feel like it is too. That's not technically a "Drive By Wire" system. I think just about all fuel injected cars/trucks have TPS at the TB, so that's kind of a moot point on the TPS being on the front of the TB to control the DBW system.
This wasn't meant to be something to split hairs or argue over at all.
But "everyone" hears/reads "01/02 are DBW", and they really are not. That's all I was getting at.
In what conditions the computer controls/regulates the throttle with the motor on the TB- I do not know. Like we've kind of all agreed on- it's at least related to cruise and VSC.
 
JayRolla said:
file:///C:/Users/Repair/Downloads/Tab_9_-_Electronic_Throttle_Control_System_-_How_it_works%20(1).pdf



Reading this is shows 2000-2002 are drive by cable.



LOL!!
Click to expand...

Woah! I wish your link was to something other than your personal hard drive, so I could see what it was! [emoji23]
But yes, my '01 is most positively drive by mfkn cable!
 
Discussions like this can get to the bottom of things.
Hear me out on this,
A poster a week or so ago said he cleaned his TB
After, engine idle was surging 2000 - 3000 rpms
He disconnected the accelerator pedal position sensor
Idle dropped to normal
Sounds like he could of gotten cleaner into the position sensor from shaft side, shorting it so to speak. This was happening not touching gas pedal.
I suggested using a nonconducting cleaner , no response back.

Does that sound like DBW to ya'll, does to me.
 
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