Engine/Transmission (1998.5 - 2002) P1689, no power, CEL, COMP- tapped

[stacerbob]

Trying to help someone else out. Somebody else told him his lift pump was bad & that I could install one for him over the weekend so he could head back to work on Monday. Truck is a 1999 3500 auto Has a Comp with the wire tapped (scotch lock) I installed the lift pump & filter, checked the pressure, all is well. he called today about 20 miles from home (after being gone all week- 600 miles driving) Stopped to get a soda, fired up, CEL on & no power- goes about 20MPH. I went out & checked the codes p1689. Cleared it, fired up & ran good, drove back home, bucked a dozen times or so usually when easing off the throttle but the light & code haven't came back on. Thinking about cleaning the connections & removing the pump wire tap. The comp was on the truck when he bought it & he runs it on level 2 all the time so he don't "need" it. Let's hear your ideas! Thanks!

 

[johncameron]

P1689 (M) No Communication Between ECM and Injection Pump Module Data link circuit failure between ECM and fuel injection pump. Low power, engine derated, or engine stops. :{ :{ :{ :{ :{



Time to order a VP-44. When I had that code my truck was



dead. https://www.turbodieselregister.com/forums/showthread.php?t=148620



been there like alot of others, sorry.



John

 

[stacerbob]

I unhooked the comp, checked the connection at the pump & went on a 30 mile round trip to pick up a Jeep with it just now. It bucked a few times but never a light or code!?!? Stock sucks.

 

[Gary - K7GLD]

That code indicates a communication problem between the VP-44 and the ECM - try unplugging and reseating the plugs on both of them, may have a simple poor connection - I'd try the VP-44 plug first.



A VP-44 failure is usually a P0216 code.

 

[jmy]

A VP44 failure can set code P1688 or P1689 alone without any other code. Sometimes you get both P188 and P1689 together.

Truck stumbling is one of the posiable indicators.



Just replaced a VP44 this past week for P1688/1689 codes.



Do a search on this site for the P1689. You find plenty of hits.

 

[Deacon_ffff]

I've had the 1689 code a couple of times now, the first time was well over a year ago, the check engine light always comes on which is how I find out about it as there are no other symptoms. I just wiggled the comp pump tap wire, and after a few starts the light went off and didn't come back on for over a year. The second time I got the code it was the same thing, light came on, I wiggled the wire, few starts later light went off no problem, that was 4 months and many miles ago. I wouldn't go dropping alot of money on a new fuel pump before checking out other possibilites first. I wonder how many fuel pumps have been needlessly replaced? It seems that everyones first solution is to drop over $1000 on a new pump. It may solve the problem, but I wonder if alot of times it was just loose/dirty connections that would have been corrected while doing the pump change? I'm sure in most cases the pump was bad as it seems that most people on here are very Knoledgable about these trucks, but I would still take the time to check everything else first.

 

[stacerbob]

Just a follow up. I did unseat & clean & apply dielectric grease to the connections. Still did it. Removed the comp & it still did it. Each time within a few hundred miles. He wanted to go ahead & replace the pump with 235K it wasn't a bad idea. A couple thousand miles & no problems since. I did hook the comp back up at that time but DID NOT tap the wire.