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Old 07-14-2012, 08:02 AM   #1
rmvlt1100
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DBW not working

Need a little help. I finely got the motor started last night but the throttle is not working. I checked all the connections and still nothing. Does any one out there have any ideas of on what to look for? Any help would be great. Thanks and have a great day.
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Old 07-14-2012, 01:00 PM   #2
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Re: DBW not working

Are you throwing any error codes? How's the idle?

Sometimes the accelerator pedal sensor is shot and sometimes the tac module is shot. Sometimes the wiring harness between the two can be wired wrong if you cobbled the system together...

Are you running the original pcm?

I guess even the throttle body could be shot.

Put a ohmmeter on the output of your pedal sensor and see if there's a change when you depress the pedal.
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Old 07-14-2012, 01:24 PM   #3
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Re: DBW not working

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Originally Posted by OldCreek View Post
Are you throwing any error codes?
I don't have the check engine light connected yet.

How's the idle?
The idle seems great.

Sometimes the accelerator pedal sensor is shot and sometimes the tac module is shot. Sometimes the wiring harness between the two can be wired wrong if you cobbled the system together..

I never mess with the throttle body or the TAC Box wiring. I will recheck those wires
.

Are you running the original pcm?

Its the pcm for the motor as far as I know.

The TAC box and the pedal came together. Not 100% sure if it came from the same truck as the engine.


I guess even the throttle body could be shot.

I bought a throttle body that was redone

Put a ohmmeter on the output of your pedal sensor and see if there's a change when you depress the pedal.
Thanks for the info I will check all of these ideas. Is it possible that the TAC Box needs to be re-calabrated with each other and/or the PCM?

If any one else has any info thanks in advanced....
Robert
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Old 07-15-2012, 11:00 AM   #4
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Re: DBW not working

Do you have the obd2 port wired in the system? If so have a tuner or use a scan tool to read the codes. You don't need a light to
give the codes. Light just let's you know you have error codes in the PCM. Make sure the pink wire going to dbw setup is going to an ignition source and check the grounds. Also did you have the computer flashed to take out all unecassary items such as vats and other security items that may shut down the system? Also whomever did your computer may have it setup for a dbc setup. Just a few items to check.
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Old 07-15-2012, 01:15 PM   #5
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Re: DBW not working

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Originally Posted by 6.0 1955 View Post
Do you have the obd2 port wired in the system? If so have a tuner or use a scan tool to read the codes. You don't need a light to
give the codes. Light just let's you know you have error codes in the PCM. Make sure the pink wire going to dbw setup is going to an ignition source and check the grounds. Also did you have the computer flashed to take out all unecassary items such as vats and other security items that may shut down the system? Also whomever did your computer may have it setup for a dbc setup. Just a few items to check.
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I do have the obd2 port hook up, so I will try that first. I am going to double check all the wires to and from the TAC unit and make sure there are connected to the right spot. I did have the PCM re-flashed to remove the VATS and added a couple of other wires for fan controllers. If everything else checks out ok I will bring the PCM back to check for the DBW set up. I had it running today and it would idle normal then the rims would raise up, I don't have the tach hooked up but it did go up quite a bit.

I read that for the system to work right the TAC and pedal should be from the same donor car. Do you know if those parts need to come from the same donor car as the PCM?

I am going to keep reading through this forum and look for other posts with the same issues. I'm sure I'm not the only one to have this problem. I'm not sure if there is enough time in the day to get through the whole forum.


Thanks for the help every bit of info helps.
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Old 07-16-2012, 08:40 PM   #6
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Re: DBW not working

Well the issue of the throttle not working I track down to a fuse on the on the stand alone fuse block not plugged in. With all the wires I passed right over that one on the double of the wires the first time. Now the thottle is working. Thanks for the help from who replyed to the question.

Now for the next issue in a new post. Thanks again.
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Old 07-14-2012, 01:09 PM   #7
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Re: DBW not working

turn your ignition to the first click, does the TB go through a 2 position check? (youll hear the servo actuate and 2 clicks.) Can you even rev it a single time?

Mismatched DBW parts often throw a code, and in my case, the throttle would work a single time after startup, and then the computer would see the error and lock out the throttle.
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Old 07-15-2012, 08:53 AM   #8
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Re: DBW not working

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Originally Posted by BR3W CITY View Post
turn your ignition to the first click, does the TB go through a 2 position check? (youll hear the servo actuate and 2 clicks.) Can you even rev it a single time?

Mismatched DBW parts often throw a code, and in my case, the throttle would work a single time after startup, and then the computer would see the error and lock out the throttle.
What did you do to correct this problem?

Thanks Robert
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Old 07-16-2012, 11:32 PM   #9
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Re: DBW not working

I gotta ask...

What do you have fused that affects the pedal and why?
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1970 K3500 1ton CrewCab 8.1L/Allison1000/NP205 Dana 60/14B!!!! - Sold
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Old 07-17-2012, 08:45 AM   #10
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Re: DBW not working

Quote:
Originally Posted by OldCreek View Post
I gotta ask...

What do you have fused that affects the pedal and why?
There is a pink wire that goes to the TAC box that needs switched power. The pedal is working now but the idle is all over the place.
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Old 07-17-2012, 12:37 AM   #11
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Re: DBW not working

^I have an aftermarket harness as well, and I have a fuse labeled "Trans, MAF, TAC" but it doesn't have any wiring that hooks directly up to the pedal, unless its built into the Tac connector/jumper harness.
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