24 Valve Engine and Drivetrain Discuss the 24 Valve engine and drivetrain here. No non-drivetrain discussions please. NO HIGH PERFORMANCE DISCUSSION!

Code P1689- ECM to IP communication, but runs ok?

Thread Tools
 
Search this Thread
 
Old 05-16-2007, 12:44 AM
  #1  
Registered User
Thread Starter
 
Timmay2's Avatar
 
Join Date: Mar 2005
Location: AZ
Posts: 652
Likes: 0
Received 0 Likes on 0 Posts
Code P1689- ECM to IP communication, but runs ok?

I've looked up alot of info on this code, and everyone seems to have it only after their truck has died and they scan for codes.

Well my light popped on today and suffice to say the VP44 is just over a year old so its out of warranty. Have always monitored fuel pressure and rarely went below 5psi. 'hoping' its not that again. LP replaced a few months ago too.

Truck runs fine, blows black smoke under throttle, gets up and goes as expected. (it does lose prime if left sitting for a couple days.. have not been able to find out why? if i let it sit awhile it takes three 5 second cranking intervals to fire.. otherwise during the day if driven recently it fires up instantly)

Double checked all the connections tonight w/ the vp44 and comp underhood and in cabin, and everything is good.

I cleared the code and ran it for a few minutes and the code didnt come back..

Guess ill update this as the days go by, but does anyone know anything else that can cause this besides the VP44?
Old 05-16-2007, 05:39 PM
  #2  
Administrator
 
phox_mulder's Avatar
 
Join Date: May 2002
Location: Sandy, Utah
Posts: 6,522
Likes: 0
Received 1 Like on 1 Post
I see a comp in your sig, perhaps it might be the culprit?


phox
Old 05-16-2007, 06:05 PM
  #3  
Registered User
 
lovinCTD59's Avatar
 
Join Date: Jul 2006
Location: Minnesota
Posts: 762
Likes: 0
Received 0 Likes on 0 Posts
I had this code before. Actually had it for a week or 2. Truck ran perfectly fine. Then, my tach started dieing, and the truck ras runnin like crap. Checked codes again, it ended up being the cam sensor. Replaced the cam sensor, and havnt seen that code once since then.. (been 6 months since then)
Old 05-16-2007, 08:13 PM
  #4  
Registered User
 
CoastalDav's Avatar
 
Join Date: May 2002
Location: Melbourne, Florida
Posts: 1,425
Received 2 Likes on 2 Posts
I had the same thing at 95K. It was the Map Sensor.

Dave
Old 05-16-2007, 09:49 PM
  #5  
Registered User
Thread Starter
 
Timmay2's Avatar
 
Join Date: Mar 2005
Location: AZ
Posts: 652
Likes: 0
Received 0 Likes on 0 Posts
First thing i thought was Comp too because i have it in the door pocket that theplug mightve wiggled loose, but it was still tight as can be. Unplugged and reconnected just to be sure.. Definetly a thing to watch though, im glad you reminded me because come to think of it alot of the search results on this code showed people with EZ boxes. Maybe a coincidence or not. Will keep an eye on it.

About 70 miles today and it hasnt come back. *knock on formica table*.

Ill check the connections on those sensors too, and keep them in mind for the next time the code pops up.

Even more reading shows this code can be completely random and come and go as it pleases..
Old 12-29-2019, 01:48 AM
  #6  
Registered User
 
Leslie47's Avatar
 
Join Date: Dec 2019
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Loses prime

My 01 loses prime when parked uphill. Parked downhill it does not. I dont know why. But try it.
Old 12-31-2019, 03:57 PM
  #7  
Registered User
 
Midnite's Avatar
 
Join Date: Jul 2004
Posts: 700
Received 14 Likes on 13 Posts
Losing prime when the truck is parked uphill is due to the fuel fitting on the back of the cylinder head loosening up and allowing air in. Usually fixed by retorquing, but sometimes also requires a new o-ring.
Old 12-31-2019, 11:19 PM
  #8  
Registered User
 
Leslie47's Avatar
 
Join Date: Dec 2019
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
I thought that was a fuel return line. Would an air bubble there affect starting ?
Old 01-05-2020, 04:54 PM
  #9  
Registered User
 
Midnite's Avatar
 
Join Date: Jul 2004
Posts: 700
Received 14 Likes on 13 Posts
You're correct, and it definitely affects starting. Very common problem.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
DEZEL INGEN
HELP!
1
06-30-2010 03:34 PM
Valv
3rd Gen Engine and Drivetrain -> 2003-2007
3
06-09-2010 11:24 AM
nitrousn
24 Valve Engine and Drivetrain
5
03-01-2009 09:44 PM
rigsy340
24 Valve Engine and Drivetrain
9
10-02-2008 07:31 PM
600 Megawatts
24 Valve Engine and Drivetrain
9
03-26-2008 07:09 PM



Quick Reply: Code P1689- ECM to IP communication, but runs ok?



All times are GMT -5. The time now is 09:49 AM.