PCM Solenoid Fuse

[Al Skierkiewicz]

Anthony,
I would check the fuse on the PDP to be sure it is still good. Visual inspection may not show an open so use a meter. Replace as needed and be sure to get it installed so that it is only about 1/8" above the PDP surface. This is tricky so just be patient. Then move the jumper on the PCM for 12 volts. At 24 volts, the solenoids might fire but the current is usually double what it is expected at 12 volts. In some cases solenoid damage may result.

While we are talking about fuses on the PDP. I have seen some teams modify the PDP to allow different fuses. This is not a legal modification. See R66 for further info.

[FrankJ]

A quick look for "solenoid fuse fault" in the PCM manual didn't find a description of exactly what that means. I suspect that it is something internal to the PCM rather than the supply fuse. Perhaps the 12 volt solenoids are overdrawing the 24 V supply and disabling the solenoid outputs. If the fault was referring the PCM supply fuse, i think it would be worded differently.

I like connecting the PCM to a 20 amp breaker slot rather than the fused output. I read table 4.2 of rule R48 as allowing that.

[Al Skierkiewicz]

Frank,
I don't think that is what R48 is saying. It is referring to only one load is allowed on the outputs designated for the PCM and VRM. It further speaks to the branch circuits in general. R44 actually points to using the PCM output marked on the PDP.

[Joe Ross]

Originally Posted by Al Skierkiewicz

Frank,
I don't think that is what R48 is saying. It is referring to only one load is allowed on the outputs designated for the PCM and VRM. It further speaks to the branch circuits in general. R44 actually points to using the PCM output marked on the PDP.

R44 allows a PCM to be connected to the same fuse as the VRM, but does not require it. R48 allows a PCM to be connected to a circuit breaker.