Why would my FICM have 58V when all I ever see mentioned is 48V. Upon further searching, I see that a 58V unit was installed by a mechanic. Is this abnormal?

 

There are FICMs available that will produce 58V, and there are also 53V units. These are offered by after market performance companies and are said to improve throttle response, fuel economy, towing capabilities, produce more power, better cold startup, smoother idle, increase injector life and all that kind of thing. Well, I don't know what is true and what is not, but it was all designed for 48V and if these units have work putting out 48V, how much extra stress is added by putting out 58V? Perhaps someone who knows more about it will chime in.

Sent from Nexus 4. IB AutoGroup

 

The voltage set-point is regulated by a pair of resistors, and changing the resistors can change the set point. It will increase the stress on the output transistors (actually Mosfets probably) since they will be handling more power, and it will increase the current load and stress on the shuttle coils that open and close the oil inputs into the injectors. It will drive those shuttles harder, so could overcome possible stiction issues. It will also let the injectors cope with cold, stiff oil a bit better. It will produce no more power, it will not change throttle response, fuel economy, towing capabilities, cold starting, idle smoothness or anything else. It's basically a modification dreamed up by an electronics geek who knew how to do it, and didn't think it through to the mechanical elements of the injector design. If it was a change that was also accompanied by upgraded power output devices in the FICM, and injectors designed for the 58 volts, then it would be fine. Keep in mind the reason the FICM voltage at no less than 45 volts is important is that the low voltage indicates failing output devices in the FICM, and the lower voltage does start to harm the injectors. All this my opinion, of course, based on a long background in electronics.

Brian

 

Sounds good to me.

 

General consensus would be if it's already there, to leave it? Or should I replace it with a 48V? I suppose I would have to check the injectors to see if they have been changed to 58V units.

 

There aren't any 58V injector coils.

 

Do you have a 58v FICM?

I just found out that I do. It did not show up on the Scan Gauge II. The Scan Gauge II shows 48.5v Why??? I had to check it at the FICM with a DVM too see it. I am also considering going back to a 48v FICM, since now I have a problem (bad miss). It did run really good for 2 years though.

.

 

I could be wrong (been wrong before) but I think the FICM output has a current limiting resistor that limits the current to 20 amps. The power through the coil will be increased with the increased voltage and may stress the coils.



.

 

High currents create heat and break down components. High voltage breaks down insulation. Name your poison. I'd stick with the factory 48 volts.