Well, driving home with the travel trailer in tow today pulling a hill at 55 minding my own business truck running great, crested the hill and bam, engine died. Coasted off to the side of the road. Checked fuel pressure from the FASS fuel pump, all good. Still no start. Get it towed home and have codes P0232, P1689 and P1688. Looks like I need an injector pump.

Well, dang! Did you get good life out of the pump?

Those three codes narrow things down a bit. By chance, did you try swapping the VP44 pump relay with another like relay? Doesn't cost anything to check.

• John

John, thanks for the response. I didn’t try swapping the VP44 pump relay. It was 8pm by the time the truck and trailer were towed back to my house. Are you talking about the lift pump relay because I put a FASS direct replacement pump on it over 40 thousand miles ago and I have plenty of pressure and volume coming from it.

John, I misread your comment, sorry long day. I’ve owned the truck since 2002, only has 128,000 miles on it. Put a FASS direct replacement pump on at 86,000 miles some twelve years ago. Was hoping that would make the pump last longer than this. Only power adder is the ez-edge three position toggle switch power box. Eliminated that and still didn’t start. The truck was running along perfect, crested a small hill, let off the throttle a little and it just shut off.

Only 128,000 miles on the truck? What year is the truck?

The fuel pump relay that I am referring to is for the VP44 injection pump. It supplies power directly to the fuel solenoid inside the VP44. It is labeled "Fuel Pump" or "Fuel Pump Relay" and it is located in the PDC. The OEM lift pumps are not relayed - they receive power directly from the ECM.

I am the original owner of my truck. I started having problems with the VP44 (P2016 code) at 65,000 miles. A year later at 87,000 miles, I had the VP44 replaced under warranty. Additionally, a relayed lift pump was fitted into the fuel tank, also covered under warranty. I have since logged over 310,000 miles on the re-manufactured VP44. Also, worth mentioning is that for the last 310,000 miles, lift pump pressure has never been over 12 psi and usually averages about 5-6 psi, so lift pump pressure really has never been causing the problems with the VP44.

Assuming your VP44 has failed and you are running the original VP44, there really is / was nothing you were going to be able to do to make your VP44 last longer. There was a lot of misconceptions regarding the VP44 injection pump failures in the early years and those misconceptions have carried on through the years. The lift pump was the least of the problems, or not even a problem at all.

Bosch recognized that there were issues with the early VP44's. Some of those were: rotors not de-burred properly during manufacturing resulting in rotor seizure, poor solder connections in the PSG, under-designed diaphragm for absorbing high frequency pulses, metallurgy problems with timing piston / bore, to name a few.

The good part is that Bosch corrected all of those issues with many revisions during their VP44 re-manufacturing process. Unfortunately, other re-builders became involved, but did not necessarily follow through with the Bosch updates. That resulted in casting a continued dark shadow over the VP44 injection pump reliability.

From an authorized Bosch re-builder, the Bosch re-manufactured pump comes with a new PSG calibrated to the pump. The combined unit is operated on the Bosch 815 test stand for three or four hours of rigorous testing. This is the pump you want to buy. They have proven to be reliable.

• John

Edited May 24May 24 by Tractorman

Very very interesting. My truck is a 2000. Second owner but bought it 2002 with 42,000 miles on it. Ya I put the FASS pump on it to be proactive but it sounds like that was futile. I bought a remanufactured vp44 last year from Industrial Injection and keep it under the passenger seat because of the time it takes to get one from them so I’ve got a pump. Ate the core charge but I didn’t want to be in bum F nowhere and have it failed and wait weeks for a good pump.

Kinda of embarrassing having my truck come home on flatbed since it’s everyone else’s vehicles getting delivered to me on flatbeds. I’ve been a mechanic for 50 plus years and had a shop at home for 38 but am limited in diagnosing these. Have two customers with second gen Dodge Cummins that I’ve recently put pumps on and it took 6 weeks to get the one.

I live in Grass Valley, Ca and we’re coming your way in two weeks on our way to Wallowa Lake. We’re staying a couple of days in Baker to see some of history museums and maybe a day trip to Sumpter to check out the dredge and mining history.

I’m going to look for that relay and replace it but I think I’ll replace the pump either way.

My wife was with me yesterday and our son came to the rescue to tow the travel trailer home and she road with him in his new 2024 Dodge 6.7 diesel. She loved it, quiet, smooth riding and twice the power of my 2000. She gave to ok for a new truck but I don’t know, love my 2000.

Thank you.

Edited May 24May 24 by WesHawkins

That sound like what happened to my truck August 21,2017. While pulling my 5th wheel heading north on highway 95 just outside of Riggens, ID. The engine died and coded P1689, injection pump gone bad. The 2000 truck had just over 88,000 miles at that time, it now has 133,000. I called @Mopar1973Man since he lives about 15 miles south of Riggins and told him what was going on. He told me what campground to take it to and ordered an injection pump from DAP. Four days later Mike and I installed it, and my wife and I were back on the road.

IBMobile, your lucky, only four days. Took me four weeks to get this one from Industrial Injection last year.

P1688 and P1689 codes show possibly a dirt power and possibly high fuel heat. Yeah i know there is a code for that but I've only seen 1 person ever report the code. Dirty power with lots of AC ripple can create the heat in the PSG circuits. For sure you need to look towards vendors that sell certified Bosch pumps to be sure to get anew PSG that has been on the test stand for 3 hours to be flashed. There are lots of cheaper pumps but used PSG and no calibration done

P1688 basically the software on the PSG no longer correct. Technically the VP44 should be capable of starting and idling without a ECM. Software issue for sure.

P1689 code can be truly a communication error cause from CANBus header being damaged. Double check the fuel pump relay to be sure it's hitting power.

5 hours ago, WesHawkins said:

I live in Grass Valley, Ca and we’re coming your way in two weeks on our way to Wallowa Lake. We’re staying a couple of days in Baker to see some of history museums and maybe a day trip to Sumpter to check out the dredge and mining history.

My wife and I will be returning from a local camping trip on Friday, June 6. If your trip to Baker City will put you here after June 6th, you are invited to our house and you could stay in a private camp site with water and electrical hookups. You could then tour the areas that you want to see at your leisure.

We would be happy to meet a member of the forum and help out if we can. Think it over - you can private message anytime you want.

I also have been turning wrenches most of my life, and have a shop and plenty of tools should they be needed.

• John

We would be happy to meet a member of the forum and help out if we can. Think it over - you can private message anytime you want.

I also have been turning wrenches most of my life, and have a shop and plenty of tools should they be needed.

Thanks John, my wife has already reserved us a spot at the rv park in town. If time allows I’ll try and message you. Maybe breakfast or lunch.

5 hours ago, Mopar1973Man said:

6 hours ago, Mopar1973Man said:

P1688 and P1689 codes show possibly a dirt power and possibly high fuel heat. Yeah i know there is a code for that but I've only seen 1 person ever report the code. Dirty power with lots of AC ripple can create the heat in the PSG circuits. For sure you need to look towards vendors that sell certified Bosch pumps to be sure to get anew PSG that has been on the test stand for 3 hours to be flashed. There are lots of cheaper pumps but used PSG and no calibration done

P1688 basically the software on the PSG no longer correct. Technically the VP44 should be capable of starting and idling without a ECM. Software issue for sure.

P1689 code can be truly a communication error cause from CANBus header being damaged. Double check the fuel pump relay to be sure it's hitting power.

I read the forums here about the AC ripple getting into the circuits. I’m considering a new alternator also this week but haven’t checked locally if new one are available. Don’t like rebuilt units if I can get new ones.

Edited May 25May 25 by WesHawkins

Well the new or rebuilt pump from Industrial Injection got the old girl back up and running. I took the opportunity while there was access to replace the gasket on the pushrod cover, reseal the vacuum pump and replace the alternator.

Of course the wife, after riding home with our son in his 2024 Dodge Ram Diesel, decided we needed a new truck. So over the Memorial Day weekend now we have a 2025 Dodge Ram 2500 diesel also. Told her I’m not selling the 2000 truck.

Good to hear you are back up and running. Good timing to reseal the vacuum pump and the side cover.

I would be very interested in hearing your thoughts regarding the 2025 Ram 8 spd transmission after you drive it for awhile. Are using the new Ram for your upcoming trip?

• John

1 hour ago, Tractorman said:

Good to hear you are back up and running. Good timing to reseal the vacuum pump and the side cover.

I would be very interested in hearing your thoughts regarding the 2025 Ram 8 spd transmission after you drive it for awhile. Are using the new Ram for your upcoming trip?

• John

Ya we will be taking the new truck on our trip. The wife decided after riding in my son’s 2024 Dodge Ram pulling the trailer home that she wanted a smoother ride after 23 years in this truck. Short wheelbase extended cab with overload springs on the rear equal a rough ride. I’m going to hook up the trailer and take it for a drive this weekend to see the difference. I love my 2000, had it for 23 years, so it’s not going anywhere for a while. Have done a lot of upgrades to it plus it’s a 5 speed manual and just fun to drive. My left leg is kinda lost in the new truck with the automatic.

I’m curious about this new transmission also. What I’ve been seeing and reading about it is it just might be a home run. I put it up on the lift today and the transmission is huge. I guess they have used these transmissions in Europe in semi’s and buses for a decade. I can’t do much to the truck yet because I got the 75000 mile warranty with no time restrictions and don’t want to give any reason to deny any warranty work.

Time will tell.

Edited May 30May 30 by WesHawkins

If you don't mind a few questions after you have had some time in the seat, I would like to know a few things regarding transmission converter lockup / exhaust brake operation under certain driving conditions.

Enjoy the truck - I'm sure it is going tow effortlessly.

• John

John

I will give an update on the truck and how it performed on our trip. I’ve only got a couple hundred miles on so far with no loads or towing and it’s been great. Don’t even feel it shift. I’ve been binge watching videos on this transmissions and haven’t found any yet that doesn’t like it. I’m 69 in July so I’d say I hope to get as many years out of this truck as I have my 2000 but if I’m still alive in 23 years I probably won’t be driving, lol.

On 5/30/2025 at 6:10 PM, Tractorman said:

If you don't mind a few questions after you have had some time in the seat, I would like to know a few things regarding transmission converter lockup / exhaust brake operation under certain driving conditions.

Enjoy the truck - I'm sure it is going tow effortlessly.

• John

John, first things first, I apologize for not getting back to you sooner and for not getting together on my trip up to Baker City and Wallowa Lake. The Wife had our scheduled wound up tight, not a minute too spare.

The new truck was fantastic with just one hiccup, the level gauge on the def tank. It would go from full to empty instantly on four different occasions but would always correct itself by just driving it or by shutting it off and restarting. Still have to get it into the dealer for that but it appears from reading other forums that this is a common problem.

The difference in power and torque when it came to towing was a huge difference and improvement from my 2000 Dodge CTD. When I went from my old gas pickup to the 2000 Dodge in 02 I was like I’m never going back to a gas powered truck again. With the new 2025 truck it’s five times that level of improvement. It’s powerful, smooth, quiet and comfortable. Don’t get me wrong I still love the old 2000 and it’s not going anywhere, just relegated to more of a work truck. Hopefully the new one will be just as reliable for me.

Again I apologize for not getting together. We’ll be back up there next June but for now it’s back in the shop as I have a full schedule of repairs lined up.

Take care.

P/S The exhaust brake is huge, down hill grades hardly touched the brakes.

Edited August 4Aug 4 by WesHawkins

Sounds like you are enjoying your new truck. I imagine that the 8 spd transmission with good converter lock-up management and good shift quality would make it an excellent transmission for just about every type of driving situation.

If the opportunity should arise, would you mind checking a couple of things and then reporting back?

I am interested in how the torque converter lock-up responds under certain specific conditions.

• What is the lowest gear (in manual shift mode) that the torque converter will lock up and stay locked up with a working exhaust brake? Please give engine rpm and road speed.

• After defining that gear, will that gear still allow the torque converter to re-lock and the exhaust brake to re-engage, if the converter was unintentionally unlocked? If so, will the converter lock up without having to gain road speed to make it lock up.

• Does the torque converter lock-up and exhaust brake operate any differently when selecting specific gears in the tow-haul mode?

These questions pertain to descending a long, steep down grade with 20 mph and 25 mph curves hauling a heavy load.

I am going to be out of town for about four days, so I probably won't have internet access for immediate future replies.

Thank you,

• John