Engine/Transmission (1998.5 - 2002) Help, truck not running and 2 codes 1688 & 1689

[JBlackwell]

Have had this truck since new, stopped at Sonic the other day and then it wouldn't fire back up. Turns over fine. Always ran perfect til then.



Found

code 1688 Internal Fuel Injection pump Control failure

code 1689 No communication between ECM & Injection pump module.





Anyone have and info on that? The lift pump I tested and was making 14. 5# fuel pressure at idle about 1,000 miles ago and 5. 5# fuel pressure at WOT.



Replaced the lift pump at 68,000 when it died and it has 106,000 miles on it now.





One thing it had been doing is pass. side battery negative post was loose and it was sparking when I turned it over. Been doing that for a couple weeks... . never had time to fix it.



Think I shorted it out with the negative loose or is the pump competely out???





Appreciate anyones help,



Justin

 

[Bob4x4]

injection pump time



Bob

 

[JBlackwell]

Yeah, but they just die like that with no warning?



Never have had a box on it, only have had RV275 injectors in it the last 12K miles. Lift pump still pumps really well.



Haven't towed with it the past 30,000 miles

 

[rkressg]

Classic signs of a Dead VP44. I recently replaced a VP44 that only had a p1688 code. When mine dies, it only had a p1689. Although, most of them die with the p0216 code.



That pump is just dead. They just die, usually with no warning.

Sorry for the bad news, but at least this is an answer.

-Rich

 

[FYarcho]

Well mine just died with a P1688. Although I did have a warning. Mine was a sudden decrease in mileage, about 2-3 MPG. Also was having intermitent hard starts, and also would smoke quite a bit more than usual, Also my EGT's were running about 100-200 degrees hotter than normal. Other than those the truck ran great. I think that if I wasnt so in-tune with my trucks normal operation I may not even have noticed these symptoms. The problem being there could be many other less expensive causes. Mine ended pretty much like yours. Truck was running great stopped to let the dogs out to do there business and then truck would't start. Only code that came up was the 1688.

 

[JLandry]

Mine ended pretty much like yours. Truck was running great stopped to let the dogs out to do there business and then truck would't start.

Might be time to stop letting the dogs out!



John L.

 

[PRout]

Sounds like heat soak might have finally gotten to it. Just curious if this is the original pump that came on the truck, or a remanufactured one. Supposedly, the newer ones with the updated electronics are tougher.

My original pump died with the 1688 after just changing the fuel filter. Ran fine driving it into the back yard. Changed filter. It would not re-start. Bled air everywhere, cranked, re-charged batts, nothing. Checked codes, 1688. Needed to replace the VP. Sorry, but maybe you'll end up with an updated one next.

 

[Gary - K7GLD]

First - and cheapest - line of defense in cases like this, is to disconnect, then reconnect the harness plug to the VP-44, to assure it isn't a simple case of contact corrosion. Guys in colder "road salt", and slushy conditions can get enough moisture inside plug contacts to cause deterioration of contact and intermittent or total loss of function.



Add to this, guys who insist upon "bathing" their engines with various chemicals and pressure washers - and you have an excellent scenario for electrical problems in the future...



Another similar potential problem area is the ECM connectors - the ECM requires proper contact and communication with the VP-44 as well - and sits lower in the engine bay - more susceptble to intrusion of corrosive garbage...



May not be the problem - but a quick and easy check point...

 

[FYarcho]

PRout Yes it was the original IP with about 89,000 on it. Your probalby right about the heat just finally did it in.



Gary I thought of that too (more like hoped for it) I did try unplugging the VP and cleaned up the connection and plugged back in I also ran down every wire I couled think of before spending the money on and VP. But as my luck would have it a new VP it is. So I installed it yesterday crossed finger and cleared the code and whala she started up. Happy she is running again just a little poorer!!. Maybe Ill sell the wife and kids? Heck I would probalby have to pay someone to take'em.

 

[PRout]

Yeah, was good thinking to check connections first. . Especially since you had the 1689 - No communication.

It's interesting you had this problem after having the bad connection on the battery. I also have suspected that I might have killed mine by cranking the starter enough to kill the batteries causing an "undervolt" condition. Looks like we both may have had an undervolt situation, or maybe was heatsoak. Guess that's why Gary has his "Magic VP Cooler" installed.

 

[tmacc]

Crap! I just pulled a 1689 on mine a few minutes ago. It's a Reman VP w/ only 28K on it. Wire's not tapped. I'll check the connections, but I'm not feeling very lucky. #@$%!