Notices
Conversions & Hybrids LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

DBW Pedal Wiring Questions

 
Old 04-18-2017, 09:27 AM
  #1  
Teching In
Thread Starter
 
Join Date: Dec 2016
Location: PNW
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Question DBW Pedal Wiring Questions

So I have some questions about the DBW pedal wiring...

I am putting a 2004 LQ4 into my 1991 Chevrolet V3500. For the pedal I am using a 1999 Chevrolet 6.5 Turbo Diesel Pedal. It bolts right up to the stock location and has the exact same pin-out as the 2004 LQ4 Pedal, although some of the pin locations are swapped around between 5 V Ref. and Low Ref. The connector is the same 10-pin Metri-pack connector, only it is keyed slightly different, but it is an easy swap to remove the Metri-pack pins from one connector and transfer them over to the other connector.

My question comes with the 3 Accelerator Pedal Position (APP) Sensors.

The 2004 stock wiring harness only seems to use 6 wires and only 2 of the 3 APP sensors are wired up. However, wiring diagrams for the 2003-2004 GM Truck Electronic Throttle Control system show using all 3 APP Sensors. I know that they have done it with 2 APP Sensors and 3 APP Sensors.

I am curious...why have 3 and only use 2? Can I wire up all 3? What is the difference? I'm just curious to know why GM did that! Are there different settings in the PCM?


2004 LQ4 Pedal Wiring Diagram


2004 LQ4 Pedal Connector


1999 6.5 GM TD Pedal Wiring Diagram

Last edited by ehjorten; 04-20-2017 at 03:10 PM.
ehjorten is offline  
Old 04-21-2017, 09:11 AM
  #2  
Teching In
Thread Starter
 
Join Date: Dec 2016
Location: PNW
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default

Since nobody has chimed in, I will add to this thread with information that I gained from a colleague at work...

Essentially, the newer computers don't use the third sensor. I don't need it and my code is not looking for it to interpolate a throttle value. It seems it was only used in the early computers for a finer resolution, but it proved overly redundant. The third sensor barely ranges 1 Vdc through the whole pedal range.

My colleague thinks GM engineers were really concerned with driveability at highway speeds. The GTOs have a line of code that divides by the 3rd sensor's position. All of the cars built later just use one sensor and then the other is there for OBD double checking.
ehjorten is offline  
Old 01-14-2018, 11:45 PM
  #3  
Teching In
 
Join Date: Jan 2018
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Default

So how did you end up wiring the 6.5 pedal with only the 6 wires? What was the pins that you used? Im trying to do this now and cant find any solid info on using that pesal on the tac modules that only use 2 app sensors!
Bmeri is offline  
Old 01-16-2018, 09:22 AM
  #4  
Teching In
Thread Starter
 
Join Date: Dec 2016
Location: PNW
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default

Using the diagrams that I supplied above with pin assignments, I was able to just swap a couple of pins in the connector and it plugged right into my 6.5 Pedal! Only the early DBW stuff used 3 sensors. The newer stuff only uses 2 sensors. My 2004 LQ4 only had 6 wires.

Brought my DBW Pedal into work and powered it up with an adjustable DC power pack. I confirmed that my pedal is wired correctly and sensor 1 and sensor 2 are within the proper output voltage range that the 2004 TAC module requires.

Now I am certain that my 1999 6.5 TD pedal will properly interface the 2004 LS and that I re-pinned the pedal connector properly. A few pin swaps into the correct connector cavities according to the previous posted diagrams was all that it took.
ehjorten is offline  
Old 01-16-2018, 01:25 PM
  #5  
Teching In
 
Join Date: Jan 2018
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by ehjorten View Post
Using the diagrams that I supplied above with pin assignments, I was able to just swap a couple of pins in the connector and it plugged right into my 6.5 Pedal! Only the early DBW stuff used 3 sensors. The newer stuff only uses 2 sensors. My 2004 LQ4 only had 6 wires.

Brought my DBW Pedal into work and powered it up with an adjustable DC power pack. I confirmed that my pedal is wired correctly and sensor 1 and sensor 2 are within the proper output voltage range that the 2004 TAC module requires.

Now I am certain that my 1999 6.5 TD pedal will properly interface the 2004 LS and that I re-pinned the pedal connector properly. A few pin swaps into the correct connector cavities according to the previous posted diagrams was all that it took.
You wouldnt happen to have a pic of the connector with the wire locations or a diagram of which wires you ended up switching around would you?

Last edited by Bmeri; 01-16-2018 at 02:05 PM.
Bmeri is offline  
Old 01-17-2018, 09:06 AM
  #6  
Teching In
Thread Starter
 
Join Date: Dec 2016
Location: PNW
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
Default

So in the above 2003-2004 GM Truck Electronic Throttle Control System diagram it shows you 9 pins, but in reality there are only 6 pins. I am not certain why it shows that, but the 3rd APP sensor is not used.

For each APP sensor you need a 5 V Reference, Low Reference (essentially ground), and the APP Sensor Signal. For each sensor signal it is surrounded by its 5 V Ref and Low Ref...they are right next to each other.

So let's look at the diagram...lower right is the 1999-2005 GM Truck Accelerator Pedal Position (APP) Sensor...Left to Right...Pin G is color White w/Black and is the 5 V Ref for APP 1. Pin F is color Dark Blue and is the APP 1 Signal wire. Pin E is color Brown and is Low Ref for APP 1. Pin D is color TAN and is Low Ref for APP 2. Pin C is color LIGHT BLUE and is APP 2 Signal wire. Pin B is color PURPLE and is the 5 V Ref for APP 2. Pins J, K, & A are not used.

Now...lets look at the 1999 6.5 GM TD Pedal Wiring Diagram...APP Sensors 1 & 2 are the ones we want. We can ignore APP 3 because it is not used. The pins we want are, from top to bottom on the diagram, G, F, A, D, C, B.

The difference between the 2 connector pin-outs are in the Low Ref for APP 1 and in APP 2 the Low Ref and 5 V Ref wires are flip-flopped.

So...from LS Connector to the 6.5 TD Pedal, Pin E needs to move to Cavity A, Pin D needs to move to Cavity B, & Pin B needs to move to Cavity D.

One final note...I think I needed to swap over the to 6.5 TD Pedal Connector body. If I remember correctly, both the LS Pedal Connector Body and the 6.5 TD Pedal body are of the same type, but they are slightly different in their clocking features that prevented the LS Connector body from fully plugging-in to the 6.5 TD Pedal. Basically just transfer over all of the wires to the proper cavity of the new connector that comes with the 6.5 TD Pedal.
ehjorten is offline  
Old 02-10-2019, 01:08 AM
  #7  
Teching In
 
Join Date: Jul 2017
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by ehjorten View Post
Now I am certain that my 1999 6.5 TD pedal will properly interface the 2004 LS and that I re-pinned the pedal connector properly.
Did you ever get the diesel pedal to function properly? I've repinned the metripak connector at the APP sensor, and I'm getting nothing when I give it throttle. I've verified the wiring several times.
chickenrammit is offline  
 


Thread Tools
Search this Thread
Quick Reply: DBW Pedal Wiring Questions


About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: