Engine/Transmission (1998.5 - 2002) P1693 - High Pressure Pump?

[socal_rattler]

Driving down the road Saturday... suddenly lost all power. I tried to restart it, but it seemed as though it wasn't getting any fuel, so I bumped the ignition a few times and let the pump run each time, finally it started again... . stumbled a little at first, but then ran OK. When I got home, I checked the codes and got only a P 1693... after some checking on the TDr, I thought I might be having a lift pump or ECM problem so I took it to the dealer. The diesel guy hooked up the diagnostic tool and read the codes and he says the codes point to a high pressure pump problem. They're gonna call DC on Monday and get approval (WTF?) to replace it.



Anybody else run into this?

 

[Bigsaint]

I never set a code with low FP and God knows I've had it with several dead Mallory pumps and the OEM. I still get an occasional P1693 code, dielectric grease on the MAP plugs works for me. Were there any companion codes set in the truck ??? I had a P0237 ( low voltage boost sensor) which, again was cured with the grease.



From what you stated, it sure sounds like the lift pump is going bad, I just never set a code with a dead one



I don't know a whole lot about the VP44, but from what I've read here, either they are working or they are DOA. There is no betwix and between from what I understand.



Scott W.

 

[MikeR]

Lift pumps don't set codes since they're not on an on-board diagnostic chain.



High pressure pump = is another word for injection pump.



-Mike

 

[socal_rattler]

Forgive my ignorance... . but is the VP44 the high pressure pump? If what BigSaint says is true and the VP44 either works or doesn't, is it possible that the lift pump causes a lack of fuel to the high pressure pump that triggered the loss of power?



BTW. . there were no other codes set in the odometer display, just the 1693.

 

[MikeR]

Yes the VP44 (injection pump) is your high pressure pump.

It is possible that a your lift pump could be dead, cutting off fuel flow, and caused your VP44 to stall then showing codes.

Put a psi gauge on test your lift pump at wide open throttle.

 

[d90boy]

So is 1693 a code that points to a specific problem or is it a general lack of communication? For instance P1693 then P0237 means, lack of communication at the MAP sensor. I think I had the 1693 too mine is the one that's hard to start uphill. Dealer couldn't replicate the problem but said if it gave that code again he'd replace the VP44.

 

[MikeR]

d90boy,



No, P1693 does not point to any specific problems, it's a generic code. See, there are two computers in the 24v trucks... the Engine Control Module (ecm), and the Powertrain Control Module (pcm).

Both computers control their own components and monitor what they control and can sense inputs from other controls or sensors, but there are a few components that do work off one another that both computers happen to read, and if that happens then this generic P1693 code comes up telling you that both the ecm and pcm have read the same failure, and to investigate further



-Mike.

 

[socal_rattler]

d90boy, as I mentioned above, mine only showed the 1693 in the odometer, but when I took it in to the dealer, they have a unit that they hook up that can read other codes stored by the PCM/ECM. I couldn't see what the guy wrote down (he was almost trying to hide it from me), but he said the codes he read pointed to the VP44.



I'm waiting still for my truck. They said DC had to approve the new pump and they wanted the shop to test fuel pressure at a couple different points first and the also wanted to know if I had any "aftermarket accessories "

 

[socal_rattler]

Update on my trip to dealer for this problem. After sending pressure readings, codes, etc. to DC engineering... . lift pump is being replaced (surprise, surprise, surprise).