7.3 ICP Wiring Issues

Marty

New member
Joined
May 19, 2011
Messages
1,288
Reaction score
0
Location
Elkton, MD
I was able to drive the truck around with the 2nd pcm for about two days without issue. I found a ground that has two in on one side and three out on the other that lays right up against the 5v signal. The grounds are for the 5v references elsewhere in the truck. I separated these wires because with the scope everywhere around that junction was extremely noisy. Basically the further away I got from it, the less sporadic the signal was, on either side. So I drove the truck around for a day with those two wires pulled out of the harness and no problem. So I replaced the ground wire and isolated them from the rest of the wires and then put everything back together.

So far so good.
 

psduser1

Active member
Joined
May 22, 2011
Messages
3,815
Reaction score
20
Location
on the road
I was able to drive the truck around with the 2nd pcm for about two days without issue. I found a ground that has two in on one side and three out on the other that lays right up against the 5v signal. The grounds are for the 5v references elsewhere in the truck. I separated these wires because with the scope everywhere around that junction was extremely noisy. Basically the further away I got from it, the less sporadic the signal was, on either side. So I drove the truck around for a day with those two wires pulled out of the harness and no problem. So I replaced the ground wire and isolated them from the rest of the wires and then put everything back together.

So far so good.

These grounds are in the engine harness, if I understand correctly? Or the chassis harness between the pcm and the 42 pin connector?
 

psduser1

Active member
Joined
May 22, 2011
Messages
3,815
Reaction score
20
Location
on the road
I was able to drive the truck around with the 2nd pcm for about two days without issue. I found a ground that has two in on one side and three out on the other that lays right up against the 5v signal. The grounds are for the 5v references elsewhere in the truck. I separated these wires because with the scope everywhere around that junction was extremely noisy. Basically the further away I got from it, the less sporadic the signal was, on either side. So I drove the truck around for a day with those two wires pulled out of the harness and no problem. So I replaced the ground wire and isolated them from the rest of the wires and then put everything back together.

So far so good.

Just wonder if some thing like this could explain some of the issues seen in the excursions?
 

Marty

New member
Joined
May 19, 2011
Messages
1,288
Reaction score
0
Location
Elkton, MD
The grounds are sent out by the PCM.

The truck is still running without issue last I heard from the customer.
 

Dakota045

New member
Joined
Nov 12, 2021
Messages
1
Reaction score
0
Any chance you remember what wires or where you isolated them, long shot on this ancient post lol
 

Latest posts

Members online

Top