Riddle me this. CPS problem
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Hotshot
Joined: Oct 2003
Posts: 17,799
Likes: 104
From: Ashland City, TN
Riddle me this. CPS problem
Okay, I'm getting the CMP fault code, or CPS fault code.
Which coorilates with my stutter while running after starting.
Why is the CPS just momentarily failing and running fine otherwise?
I checked the wiring today, not a wiring issue.
Truck runs great (cept for my serpentine belt squeel)
So....
Why am I getting the momentary fail, but the truck going fine otherwise?
I think its during the idle down change.
Thoughts?
Which coorilates with my stutter while running after starting.
Why is the CPS just momentarily failing and running fine otherwise?
I checked the wiring today, not a wiring issue.
Truck runs great (cept for my serpentine belt squeel)
So....
Why am I getting the momentary fail, but the truck going fine otherwise?
I think its during the idle down change.
Thoughts?
Postmaster
Joined: Sep 2007
Posts: 4,195
Likes: 6
From: Medford Oregon
WAG, maybe a fuel issue. PCM pretty much controls everything but doesn't know anything about fuel pressure, nor does it care. It just assumes the pressure is there and if it can't maintain commanded rpm I can see where CPS might be blamed for the fault. Once again just a WAG .. maybe air getting into the fuel system after shutdown?
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Hotshot
Joined: Oct 2003
Posts: 17,799
Likes: 104
From: Ashland City, TN
WAG, maybe a fuel issue. PCM pretty much controls everything but doesn't know anything about fuel pressure, nor does it care. It just assumes the pressure is there and if it can't maintain commanded rpm I can see where CPS might be blamed for the fault. Once again just a WAG .. maybe air getting into the fuel system after shutdown?
It's definitely not a fuel hick-p.
It's a good guess, but I'm not thinking so. That would usually mean a hard start as well.
Hotshot
Joined: Aug 2006
Posts: 10,764
Likes: 39
IIRC ,Code is only set after 7 seconds of no sig...
Which code was set ?
Which code was set ?
P0340: Inactive CMP signal detected during engine cranking when ICP pressure was sufficient for starting.
P0341: Electrical noise detected, check wire routing and grounds.
P0344: Incorrect number of sync to transition counts detected, possible intermittent CMP sensor/circuit fault.
P0341: Electrical noise detected, check wire routing and grounds.
P0344: Incorrect number of sync to transition counts detected, possible intermittent CMP sensor/circuit fault.
Post Fiend
Joined: Mar 2007
Posts: 26,966
Likes: 50
From: Texas
When mine acted up, it would stutter at random going down the road. It felt like an intake backfire out of an old gasser. Just a split second stumble while I was driving. After 4 or 5 times during one drive,the CEL finally came on from a code. I don't remember which code it set, but a new CPS fixed me up (before they became so cheap).
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Swat_Medic
1994.5 - 1997 7.3L Power Stroke Diesel
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May 13, 2018 02:20 PM
