Hey, I'm throwing a cel 42, anybody know where I need to start looking. I have money to just replace parts, so what do I need to replace? Any help is greatly appreciated as usual. Thanks ~Jeff

From what i get off the PCM code list:
No MFI relay (ASD relay) output voltage at PCM :: Harness and connector / MFI relay (ASD relay)

MFI relay (ASD relay) control circuit :: Harness and connector / Fuel pump relay

Fuel pump relay control circuit :: Harness and connector / Fuel pump relay

i'd start with the ASD relay, or if you can verify its good, start looking for loose/broken wires.

What exactly is happening with a code 42? Is it bad that the motor is brand new with only 200 miles on it? I bought a gauge cluster and didn't realize the CEL buld was removed until now. I think I have had that code from start up on the motor. Is that bad? Thanks.

Seems odd, that the code would be for asd relay problems and the car runs correct. (or is it not running correct?)

No, it runs great, didn't even know there was a problem. It does idle rough though, but I have Crower 2's.....?

are you running a completly standalone fuel system or someting else that might enadle you to run w/o the asd relay, or have dis-connected it to hook something else up? i dunno im kind of stumped.

Nope, stock fuel system other than the walbro 255. Stock ecu as well. Just higher compression and cams.......I am stumped as well.

Well, it sounds like it's definitely either the ASD or fuel pump relay. If it's running okay, I suspect the ASD relay, since a loss of voltage across the fuel pump relay would result in the pump not running.

You might grab a schematic and test the ASD relay with your meter. When the ECU doesn't get the right signal from CMP or CPS, it will energize that relay to prevent the engine from firing. If the relay tests out alright, I think your next step would be to ohm out the four wires that run to it for continuity. Since the ECU has to energize the ASD to kill the engine, the fact that the car runs leads me to believe that the ECU doesn't think the ASD is connected.

Shit. Try disconnecting it and then reconnecting it. :shrug

Originally posted by DR1665
Well, it sounds like it's definitely either the ASD or fuel pump relay. If it's running okay, I suspect the ASD relay, since a loss of voltage across the fuel pump relay would result in the pump not running. You might grab a schematic and test the ASD relay with your meter. When the ECU doesn't get the right signal from CMP or CPS, it will energize that relay to prevent the engine from firing. If the relay tests out alright, I think your next step would be to ohm out the four wires that run to it for continuity. Since the ECU has to energize the ASD to kill the engine, the fact that the car runs leads me to believe that the ECU doesn't think the ASD is connected. Shit. Try disconnecting it and then reconnecting it. :shrug

Well, I reconnected it and reset the computer, no code going on 100 miles now. :) If there is in fact a problem with it, it's not going to hurt my motor is it? Thanks for all the help.

Originally posted by powellds

Originally posted by DR1665 Well, it sounds like it's definitely either the ASD or fuel pump relay. If it's running okay, I suspect the ASD relay, since a loss of voltage across the fuel pump relay would result in the pump not running. You might grab a schematic and test the ASD relay with your meter. When the ECU doesn't get the right signal from CMP or CPS, it will energize that relay to prevent the engine from firing. If the relay tests out alright, I think your next step would be to ohm out the four wires that run to it for continuity. Since the ECU has to energize the ASD to kill the engine, the fact that the car runs leads me to believe that the ECU doesn't think the ASD is connected. Shit. Try disconnecting it and then reconnecting it. :shrug

Well, I reconnected it and reset the computer, no code going on 100 miles now. :) If there is in fact a problem with it, it's not going to hurt my motor is it? Thanks for all the help.

My ASD rely has been out for a while. When I say out I mean going out, it's still in he car and connected but sometimes the car won't start. I have to tap the relay and VRrrroom the car will start...Just always forget to buy a new one till it has to be tapped.

Good Luck and no you can't do any damage fooling with them.