check engine light, code readers, etc. (1 Viewer)

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Joined
Jun 6, 2003
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2,603
Location
Cuyamaca, CA and Las Vegas, NV
Just replaced the starter yesterday. Throwing a check engine light. Everything appears to be hooked up properly. Truck doesn't want to idle.

Any ideas about the above problem?


For those of you with scan tools (code readers), what models allow you to pull and reset codes? I don't currently have a palm pilot or laptop so some of the fancier stuff is out of the question.
 
Just a punt, disconnect all connectors you pulled off and put them back together again, quite possibly a loose connector on a coil or something, or something is not quite plugged together properly and an ECU is not getting the correct feefback from a sensor or similar.
 
That's where I am right now. Reverse reverse engineering:doh: Hopefully in my haste I didn't connect something well enough.
 
33 views and no more help:crybaby:

I checked all the vacuum lines and such and there is no leak so I'm pretty sure that stuff is working fine.

Now I am figuring something is going on with the throttle body assembly. Something is going on with the throttle control motor. If I disconnect the magnetic clutch, the motor idles fine. Of course then you can't use the throttle:doh:

I think maybe it threw the diagnostic trouble code 1125 and/or 1126. If this code is stored, the ECM shuts down the throttle control motor by disconnecting the magnetic clutch.

If I can clear the code, then I can see if it throws the same code again.

So my question is, do the handheld code readers have the ability to clear the code from the ECM? If not, how the heck do I clear it? And no, pulling the battery cables doesn't do it.

Or maybe the TPS is bad?

:censor: technology.
 
have you tried disconecting the battery yet?
 
I asked a couple of Toyota techs, and they say that yes, a Toyota diagnostic reader can reset trouble codes, but when I run your scenario by them..they are quite perplexed. They all seem to agree that it is too coincidental that it occured when you re-assembled everything to be a component failure. The most educated guess was that maybe the ground strap was disturbed under there, a wire(s) in the harness was pulled too hard , or the coils perhaps even injectors where plugged back in out of correct order.

I am not questioning your installation myself, in fact, It sounds like you know exactly what you are doing...I am just giving various possibilties from some guys who do this (starters on a 100s) all the time.

Good luck !
 
Yes, they will clear codes. You can also go to most automotive stores and have them check & clear them for you, for free.
This unit is the one I have www.iequus.com/item.asp?cid=7 and it works ok. This one is supposed to be better than the 3100? I’m still looking to get a good laptop version. This will allow me to see various components and check values, not just see if it’s coding or not.
DMX
 
SINCITY100 said:
I asked a couple of Toyota techs, and they say that yes, a Toyota diagnostic reader can reset trouble codes, but when I run your scenario by them..they are quite perplexed. They all seem to agree that it is too coincidental that it occured when you re-assembled everything to be a component failure. The most educated guess was that maybe the ground strap was disturbed under there, a wire(s) in the harness was pulled too hard , or the coils perhaps even injectors where plugged back in out of correct order

The last thing I noticed last night when I was done working on the truck was that the battery seemed to be dying?

This leads me to believe something is going on with the electrical system, maybe the alternator or the voltage regulator or something?

I triple checked all the connections on the starter and the starter ground, etc. When I reinstalled everything. I compared the pictures I took with the current condition of the motor and everything appears to be in the right place.

The starter itself is working great, LOL:)

I'm busy the next few days so I won't look at it again till Sat.
 
the ck eng lamp indicates a problem that currentley exists if it wont clear by disconnecting the batt.
I have pinched the intake gaskets several times putting back the manafold , usually throws a code p0171 lean or p0174 , possibly a p0300 through p0308 misfire , if you retouched all the connecters you removed then you should look and see what the code is as this will shorten your span of failures ,
as a side note it is common to have it idle poor after it has run for a few months/years and having the batt go dead

fix for idle is

this happened to me a few times at work , You need to pull the throttle body off and clean out the black gunk from around the throttle blade , or the quick fix is to pull the air intake off and open the throttle manually and with a rag and brake/carb cleaner clean around the blade as best as you can ,, while performing this have the batt disconectd ,
Over time carbon builds around the blade and changes the air flow past the blade. in small amounts the ECU will then compensate and pull the throttle open to the correct flow spot , it will go to that spot untill the throttle is disconnected or the batt is disconnected or the ecu is reset .
Then when it wakes up it goes to its first factory program ,, Which will be incorrect due to the build up , and will idle low ,,,,, and or high ,, depends on the factors involved ,
just replaced one this morning that when started went to 1100 rpm untill it was reset .


Hope it helps
Fj55-100
 
fj55-100 said:
the ck eng lamp indicates a problem that currentley exists if it wont clear by disconnecting the batt.
I have pinched the intake gaskets several times putting back the manafold , usually throws a code p0171 lean or p0174 , possibly a p0300 through p0308 misfire , if you retouched all the connecters you removed then you should look and see what the code is as this will shorten your span of failures ,
as a side note it is common to have it idle poor after it has run for a few months/years and having the batt go dead

fix for idle is

this happened to me a few times at work , You need to pull the throttle body off and clean out the black gunk from around the throttle blade , or the quick fix is to pull the air intake off and open the throttle manually and with a rag and brake/carb cleaner clean around the blade as best as you can ,, while performing this have the batt disconectd ,
Over time carbon builds around the blade and changes the air flow past the blade. in small amounts the ECU will then compensate and pull the throttle open to the correct flow spot , it will go to that spot untill the throttle is disconnected or the batt is disconnected or the ecu is reset .
Then when it wakes up it goes to its first factory program ,, Which will be incorrect due to the build up , and will idle low ,,,,, and or high ,, depends on the factors involved ,
just replaced one this morning that when started went to 1100 rpm untill it was reset .


Hope it helps
Fj55-100

You are saying to spray the cleaner on the rag & wipe it out, not spray it off then wipe it out. I know on my car, if carb cleaner is sprayed into the TB, then it causes the TB shaft seals to break down, causing vacuum leaks.
DMX
 
DMX84 said:
Yes, they will clear codes. You can also go to most automotive stores and have them check & clear them for you, for free.
This unit is the one I have www.iequus.com/item.asp?cid=7 and it works ok. This one is supposed to be better than the 3100? I’m still looking to get a good laptop version. This will allow me to see various components and check values, not just see if it’s coding or not.
DMX


Going to pick up the 3110 model, which will also work with newer CAN enabled vehicles.
 
S W E E T !
The 3030 also does the CAN, however the one you got is way nicer than mine IMO.
 
Well, I bought the 3110. They can be had for around $179-$199. From what I can tell so far, it is a nice unit. I went ahead and got the newer model since it works with the newer CAN protocal as well as OBD2.

Anyways, I pulled the code PO115, which is Engine Coolant Temp. Circuit. The scan tool is showing an "open cicuit". Guess that is better than a "short".

Now, hopefully I just have to trace the source of that open circuit. Hopefully something isn't plugged in or loose rather than a problem with the harness somewhere.

I don't see how an "open circuit" in the engine coolant temperature circuit can cause the truck to run like this? Damn technology is making me wish I had a 2F in my LC.
 
This will cause your car to run rich all the time = poor performance & economy.
 
calamaridog said:
Damn technology is making me wish I had a 2F in my LC.


Then you could get "poor performance and economy" all the time. :D
 
DMX84 said:
This will cause your car to run rich all the time = poor performance & economy.

What about not running at all? Damn thing still doesn't want to idle.

I think I will clean the TB and then check all the connections related to the engine coolant temp. circuit and go from there.

Needless to say, thanks for the feedback, it helps me feel like I'm doing something.
 
Try spaying carburetor cleaner around the intake gasket and/or any vacuum lines to find out if it is leaking. The cleaner will get sucked in and will cause it to act up, you will be able to tell if it is leaking vacuum in the area you are spraying.
Although this will probably not fix the temps sensor, it may help figure out why it’s not idling
Hope this helps.
DMX
 
Well, I'm done. Truck runs great.

I cleaned the TB as suggested and checked all the electrical connectors in the engine coolant temperature circuit.

One of the electrical connectors had debris stuck in it... cleaned it out and plugged it back in:doh:

Cleared the code and everything is fine.

Thanks to everyone who helped:eek:
 

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