97 7.3 crank no start p1668 code

[wildbillcodyk9034]

Truck ran good all weekend, wife went to start it today and no start. Get home from work and have crank no start, change CPS figuring that was the problem no dice.

Check scangauge and find p1668 code. Clear it crank no start same code.

Cleared code and did buzz test again no buzz with the p1668 code coming back.

Cleared code unhooked ts chip crank no start with p1668 code again.

All wires look good and nothing frayed.

I’m thinking it’s the IDM, anyone else?

Please help down to one vehicle for me and the wife and both work tomorrow


Sent from my iPhone using Tapatalk

 

[Magnum PD]

Do you get a “wait to start” light?

 

[wildbillcodyk9034]

Yes sir


Sent from my iPhone using Tapatalk

 

[Bugman]

According to the code it could be the PCM or the IDM along with their wiring or the power to the IDM including the ground to the IDM.


Sent from my SM-J737V using Tapatalk

 

[wildbillcodyk9034]

Not sure if that helps, I have not seen any chafed wires to the idm and nothing under the dash. Not sure what else to test at this point.

Is there any way to test it other than a known running truck?

Sent from my iPhone using Tapatalk

 

[Bugman]

Change relay #2 in the under hood box, that is the one for the IDM. The fuse should be good since it is on #9 which is also the PCM fuse.

I don't know of any way that a person could test it other than finding someone with a 94-2003 Powerstroke with the 7.3 and swapping them.

 

[Bugman]

You can also check for power on pin #14 on the IDM plug with the key on to make sure that it is getting power. The code that you are getting also says that there could be a problem with the Electronic Feed Back Signal Output from the PCM but I am not sure what values you need to see on that. It may be a 0.5 volt reference voltage

 

[wildbillcodyk9034]

I will pick up a relay and hopefully can borrow an idm. Will have to find my multimeter and start phoning things out after work tomorrow.

Thank you and will let you guys know what happens.


Sent from my iPhone using Tapatalk

 

[Patrick Feeley]

Just thinking out loud: Doesn't that IDM have the "140V" mod done to it (it looks like it)? Not sure if that might cause any problems like you're describing if the mod went south??? Cheers!

 

[wildbillcodyk9034]

Yes sir I did that 6 or 7 years ago. All the solder looked good but who knows.

Picked up new IDM and 3 extra relays just in case tonight. Swapped in new IDM and she cranked up and ran

Thanks everyone for the help


Sent from my iPhone using Tapatalk