Im not understandin what this mod is can anyone help what it is and what it does, what are the benefits and how is it done?

 

Fools your truck into raising ICP. No need for you to do it since you have a chip.

 

dont waste the time

 

Since you asked a few questions here, I will try to answer them....instead of just telling you that it's not worth the time.

This modification is pretty simple as it's just a resistor wired into the truck's engine wiring harness. HOW you attach the resistor is VERY important. Wire taps (Scotch Locks) are a BAD idea as are any methods that don't involve solder or sealing. These engines vibrate A LOT so anything that isn't secure WILL come loose over time and you certainly don't want any moisture or contaminants finding their way into the conductor portion of the harness or you'll be chasing electrical gremlins in short order.

To understand WHY this modification is made, you have to understand what the injection control pressure sensor does, how it works, and how its output effects the PCM's operation. The ICP sensor is there to tell the PCM the ACTUAL pressure that is created by the high pressure oil pump. The PCM is programmed to maintain certain pressures depending on the inputs of other sensors and operator demand. The ICP sensor is a variable resistance sensor. The PCM sends out 5 volts to the sensor and a ground. The third wire is there to return voltage back to the PCM. The voltage will vary depending on pressure in the HPO rail. Higher return voltage means that the pressure is higher and conversely, lower voltage means that the pressure is lower.

Now, there are two ways to do this modification. You can wire in a resistor in parallel with the injection control pressure sensor or you can wire it in series. Understanding Ohm's Law will help immensely with following the things I'm talking about. The first versions of this modification were designed to be wired in parallel with the sensor. This setup used a resistor that was used as a shunt to bypass some of the ICP voltage to ground; effectively lowering the signal voltage going back to the PCM. Remember the relationship of voltage/pressure. The latest versions of this modification simply involve putting a resistor in series with the sensor signal wire. This in itself lowers the signal voltage back to the PCM.

You may ask yourself, "Why do we want to lower the voltage that the PCM is seeing coming from the ICP sensor?". Well, if you recall, the PCM is programmed to maintain a specific injection pressure based on a few things. Lowering the voltage that the PCM is "seeing", will cause the PCM to try correcting the pressure "problem" (even though there isn't a problem) by raising the injection pressure (by raising the injection pressure regulator duty cycle) until the desired value is reached. The more one "fools" the PCM input, the greater the artificial rise in injection pressure.

Back to the circuitry part of this....

If you wire in parallel, you will need a very high resistance (10K Ohm for instance) and the lower you go, the higher the actual pressure will become.

If you wire in series, you need a low resistance (i.e. 10 Ohm) and the higher you go, the higher the actual pressure will be.

Hope this helps.

 

Thanks for the info.
so pretty much there is no need for me to do it?

 

Nope, no reason at all.

 

So if you were having a problem with low pressure, you could compensate by using this mod? or was there some other reason for this mod?

 

If you're having a problem with low pressure, nothing is going to "fix" it short of new hard parts that are causing low pressure.

The only reason for this modification is to increase injection pressure for a little more fuel for a given injector pulse width and slightly earlier start of combustion. It's a cheap way to get a few more horsepower because everything else staying constant (as far as the PCM is concerned), you're getting a little more fuel.

 

I heard it gives you more hp

 

Maybe 10hp? Honestly its not worth the time