How to increase voltage?

[oxman504]

I'm working on putting a Allison 6 speed in my truck and I'm trying to use the the original TPS to give the TCM a TPS signal. The problem I'm running into is the original TPS starts at .43-.45 volts DC but the TCM needs to see at least .55 volts or it will set a code. Is there a way to increase the voltage that the TCM sees but still have the same .45 volts going to the ECM? I would think that I could used a diode before the increase so the ECM won't see the higher voltage.
Please dumb it down as much as possible.

 

[BobK]

Sorry, I do not speak TLA.

Bob

 

[oxman504]

Sorry, I do not speak TLA.

Bob

What is TLA?

 

[oxman504]

TPS= Throttle Position Sensor
TCM= Transmission Control Module
ECM= Engine Control Module

 

[KMoffett]

What is TLA?

TLA is Three Letter Acronym. It's a slam at people that use TLA's, as if every knew what they mean.

Ken

 

[oxman504]

Yeah I figured that already hence why I describe them. Can I I get a real answer to the original question?

 

[Gryd3]

I'm working on putting a Allison 6 speed in my truck and I'm trying to use the the original TPS to give the TCM a TPS signal. The problem I'm running into is the original TPS starts at .43-.45 volts DC but the TCM needs to see at least .55 volts or it will set a code. Is there a way to increase the voltage that the TCM sees but still have the same .45 volts going to the ECM? I would think that I could used a diode before the increase so the ECM won't see the higher voltage.
Please dumb it down as much as possible.

The .43 - .45 Volts DC is a pulsed DC is it not? Is there a problem with providing the slightly higher voltage to the ECM?

A Diode will not usually even conduct below 0.7V, so your signal would not go through...


I spoke too soon... and didnt think about my answer. The throttle position is variable... its the cam positioning sensors I was thinking of...

 

[oxman504]

It's not pulsed. It works off of resistance. The further you push the pedal the higher the voltage.

I would think that if the ECM saw higher voltage it might read as a higher throttle %.

 

[Gryd3]

Do you have any other values?
Voltage at 0% throttle, 50% throttle, and wide-open?

 

[oxman504]

Yes it is linear. At 0% throttle it's at .43-.45 and at full throttle it's a 4.5 volts.

 

[Gryd3]

Are there any side-affect you are trying to avoid by sending the .55V to the ECU?

Is there a problem with sending 4.6V to the TCU?

The only thing I can think of is an additional TPS (one for the ECU, and one for the TCU)
or a voltage adder circuit.
Perhaps someone else has an alternative.

 

[oxman504]

Yes there are problems with that. The Dodge Cummins Throttle Pedal or TPS has descending and ascending voltages. It is feed by two 5v wires then has two signal wires and two return wires. The ECM uses the descending and ascending voltages to check each other out.

As a last resort I was going to use another TPS, but it's going to be challenging to make a bracket and finding a TPS with the same throw as the TPS gas pedal. The TPS is the gas pedal on a 05+ Dodge truck.

 

[Gryd3]

Can you provide some kind of diagram of the connections required and what they do?
Does the TCU require both sides of the TPS like the ECU does?

 

[oxman504]

I'm going to make another TPS bracket so the little crying 3 year old of a TCM will be happy. It wants its own. Thanks for you help.

As of now I'm going to use a TPS for a 88 Chevy S10 4.3. It has a sprung arm made onto it. So that should make things a little easier.