Engine/Transmission (1998.5 - 2002) P1689 code...something is not right

[JR2]

Okay so my truck has been throwing a check engine light. When I pull the codes I get the normal ones and 1689, which is no comms between the injection pump and ECM. I initially thought, injection pump time, but reading about it now I am not so sure. There are no other codes pointing to the injection pump or anything else. Here is the strange part, when I get the check engine light if I cycle the key a few times the truck will start and run fine, also some times driving down the road I hit a bump and will get the check engine light and get a quick shudder of the engine and everything goes back to normal. The times when cycling the key does not work the truck still starts it just has wild swings in RPM and eventually dies. I am thinking maybe I have a grounding problem or maybe a bad relay. Going to swap some relays today and look at the grounds.



Anyone have a similar problem and have it not be the injection pump?

 

[Ram4Sam]

Okay so my truck has been throwing a check engine light. When I pull the codes I get the normal ones and 1689, which is no comms between the injection pump and ECM. I initially thought, injection pump time, but reading about it now I am not so sure. There are no other codes pointing to the injection pump or anything else. Here is the strange part, when I get the check engine light if I cycle the key a few times the truck will start and run fine, also some times driving down the road I hit a bump and will get the check engine light and get a quick shudder of the engine and everything goes back to normal. The times when cycling the key does not work the truck still starts it just has wild swings in RPM and eventually dies. I am thinking maybe I have a grounding problem or maybe a bad relay. Going to swap some relays today and look at the grounds.



Anyone have a similar problem and have it not be the injection pump?

I haven't had this issue, but if hitting a bump causes the issue, I would check all the connections where things plug in or plug together. Clean them all and make sure they are plugged together tight.



Sam

 

[JLandry]

Ditto what Ram4Sam said. It sure sounds like an intermittant connection in either the power or datalink to the VP44.



In addition to swapping the fuel injection pump relay in the PDC, I'd also disconnect the 50-pin ECM connector and the VP44 connector, carefully examine and clean the pins using contact cleaner spray, then reconnect.



If this problem goes from intermittant to continuous, I can post some specific wiring harness troubleshooting steps.



Good luck,



John L.

 

[JMetzger]

Like Ram4Sam & JLandry said I also had the 1689 code & all it was was poor connections. I took mine to Dynamic Diesel in Reno, NV & the tech said that older trucks like yours & mine are starting to develop dirty connections. They cleaned the ECM, VP44 & the rest where there was a connection & fuse box etc. That was over 20,000 miles ago & knock on wood it is still going with no problems.

 

[JR2]

Put it in the drive way today, as long as it does not rain on me tomorrow I plan on checking all the connections ECM-VP44 etc. Will let you all know if I find anything. I did swap the relay yesterday and had the check engine light come on today so that was not it.

 

[RobertBradford]

Here's my bad news... . Mine did the same thing and all the connections were clean, VP 44 pump seems to be good, ect. End results I'm replacing the ECM. Now if you have to go to that stage please taking my warning... RESEARCH who is doing the ECM!!! I sent mine to ECM outlet out of Detroit, MI (found them on the web) and the stole the thing!!! Thankfully I didn't give the the $675 they wanted up front. Now I had to buy one through a friends auto shop and hopefully will be installed by Friday.

 

[JR2]

Pulled the connections to the ECM, Data Link, VP$$ and APPS today. All looked good and I put a bit of dielectric geese on them just to be sure. Also checked the grounds on the batteries and they look fine. Took it for a drive and at a random time I got a sudden drop in power and check engine light. I have not pulled the code but I am fairly sure its going to be a 1689.

Now what. .

 

[JLandry]

Now what. .

I think I'd try a wiggle test next...



With the truck running in your driveway, have someone hold the engine rpm at anything above idle while you wiggle the wiring harness around near the VP44 and ECM to see if you can duplicate the problem.



John L.

 

[Missouri Mule]

JR2, did you spray the connectors out with contact cleaner. The pins mite look clean but have some type of build up on them.

When my back-up light switch quits working the connectors looks clean too, but I spray them out with lubricating contact cleaner(cleans the best), let it sit five minutes then spray out with a drying contact cleaner and I have back-up lights again.

 

[JRauh]

I just had the same problem, but besides P1693 I got P1683 as well. Turned out to be the crank sensor! Electronic tomfoolery, if you ask me!

 

[JR2]

These trucks can do strange things when a sensor is intermitiant... . its worth a shot on mine as I can not find anything else that is wrong. Now I just have to remember where the crank sensor is on my O1, its either behind the starter or behind the VP44... .

 

[JLandry]

These trucks can do strange things when a sensor is intermitiant... . its worth a shot on mine as I can not find anything else that is wrong. Now I just have to remember where the crank sensor is on my O1, its either behind the starter or behind the VP44... .

JR2,



Your truck should only have a camshaft position sensor under the VP44 (no crankshaft position sensor).



See THIS POST for some helpful info.



Best regards,



John L.

 

[NIsaacs]

Unplug your Edge Drag Comp and try it. My first Edge EZ did this. I sent it back and they sent me a new up-dated one, all has been well for years.



Nick

 

[JR2]

The truck finally died while I was visiting the service manager at my dealership. I had them replace the injection pump with a new one I supplied and the truck is running great again.

 

[JR2]

Well after driving a couple hundred miles with the new pump the problem is back... Its not the pump... back to the drawing board I guess. Time to go buy some contact cleaner and start checking grounds again.

 

[JR2]

After much searching, cleaning and generally talking bad about the truck I disconnected the Edge Comp (again) and the problem has not happened in two weeks. Guess I have to talk to Edge about doing something about it now.

 

[JR2]

After much searching, cleaning and generally talking bad about the truck I disconnected the Edge Comp (again) and the problem has not happened in two weeks. Guess I have to talk to Edge about doing something about it now.