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?

http://www.lsenginediy.com/wp-conten...015/02/193.jpg
2004 LQ4 Pedal Wiring Diagram

https://ww2.justanswer.com/uploads/G..._connector.gif
2004 LQ4 Pedal Connector

http://fourseasonsroofingandsiding.c...3d80087024.gif
1999 6.5 GM TD Pedal Wiring Diagram

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.

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!

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?

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.

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.

Actually only pins E and A need to be swapped -- I thought that B and D would as well based on the diagram, but I didn't and it seems to work just fine.

Same thing with me did you have any luck fixing it?

Good post and over 10 yrs old
 

Had my drive by wire on an old LS sawp suddenly quit. Already replaced pedal and issue returned with same symptoms as you.
going to get a new throttle motor tp fix.
great write up.

Need Help with this
 

I have a Standard Ignition APS130 Accelerator Pedal Sensor that fits the 71 C10 i did the LS swap in. The LS Swap is from an 07 Silverado and the pedal positioner plug has 6 wires from right to left, (A)TAN, (B)GRAY, (C) PURPLE, (D)WHT/BLK, (E)DK BLUE, (F)BROWN. Lets name these the LS wires. The pedal assembly is pinned as your initial post shows. I have wired it as shown in the picture and swapping the E and A but no luck whatsoever. What am I missing?
https://cimg4.ibsrv.net/gimg/ls1tech...b8d85e331c.jpg
LS connector with values listed on right and pin assignments by this post on left margin