Toyota Tundra wont idle and shuts off....

Joined
Apr 4, 2007
Messages
19
Likes
0
Points
0
Location
San Diego
#1
Hi Fellas I am working a 2002 Toyota Tundra with a 4.7 engine, The problems is the it wont idle or stay on,it runs perfectly fine with no check engine light or pending codes as well it just wont stay idle. So I thought Okay maybe IAC motor is stuck or needs replacement, After few minutes looking around the Throttle body components I dont see the the IAC valve. So I run thru the repair manual and found that they use what is called a "Accelerator Pedal Position Sensor " According to the manual there is a DOT to DOT that should match evenly, But I found them uneven. Should the sensor be replace or are they adjustable ??? Thanks in advance Pepe
 

jjm

Hero Member
Joined
Dec 1, 2006
Messages
349
Likes
0
Points
0
Location
NYC
#2
This vehicle has ETCS (Electronic Throttle Control System) as you've now found out.

Is the MIL light on? Any codes? Can your scan tool read TP values? If so what are your values at idle, both as percent and voltage?

Can you hear the operation of throttle control motor while the accelerator position sensor is moved? Does it sound smooth, without any noises or binding?

Resistance on the 1 and 2 connector of the throttle control motor should be .3 to 100.0 ohms at room temperature (68F). 3 and 4 should be 4.2 to 5.2 ohms

Resistance on the throttle position (TP) sensor between the VC and E2 terminals should be 1250-2350 ohms, also at room temperature.

Resistance on the accelerator position (TP) sensor between the VC and E2 terminals should be 1640-3280 ohms, room temperature.

System is can make you crazy, you might want to consider an <a href="http://www.myaffiliateprogram.com/u/alldata/t.asp?id=1035" target="_blank">AllDataDIY</a> sub for more detailed troubleshooting and diagrams.

Joe




If you found this information helpful, please support BATAuto!

 
Joined
Apr 4, 2007
Messages
19
Likes
0
Points
0
Location
San Diego
#3
Thanks your reply Jim I scanned the truck and found no codes, I will run the test you mention Jim but what is it that keeps the idle maintain where it should be the Accelerator Pedal Position or the Throtle Control Motor?? I will see if my scan tool Is capable of reading the TPS values.. Will keep posted
 

jjm

Hero Member
Joined
Dec 1, 2006
Messages
349
Likes
0
Points
0
Location
NYC
#4
There are two sensors on this thing and one motor.

The throttle control motor is actually what opens the throttle.

The accelerator position sensor senses the gas pedal position.

And the throttle position sensor senses the actual throttle position - essentially monitoring what the throttle control motor is doing

Input from the accelerator position sensor may not necessarily translate into action by the throttle control motor, that's what the throttle position sensor is for, to tattle tale to the PCM.

Since the vehicle is not idling, and no codes are set, something is probably off ever so little.

Joe

If you found this information helpful, please support BATAuto!

<a href="http://www.batauto.com/php/donate.php"><img src="http://www.batauto.com/images/donate.gif">
 
Joined
Apr 4, 2007
Messages
19
Likes
0
Points
0
Location
San Diego
#5
Thanks for the input Jim I found that the Throttle body butterfly was very dirty blocking the clearance to keep engine at idle when throttle is shut down.The truck has 95,000 miles on the clock so it was time for a throat check, I clean the whole throttle body very good and it was back to normal Thanks again :h: