Engine/Transmission (1998.5 - 2002) Bucking at 50 MPH PCU Code P1693

[DBeeman]

Along with P ECU Codes of 1698, 0215, and 0562. Truck has been out of the shop for about 3 weeks, I had them troubleshooting a slight surge at 35-55 MPH. $3200 later, they told me they couldn't find anything except the lift pump, which they replaced with a DDRP. Has them install a gauge as well, new pump is sitting at 18-20 PSI at highway speeds. It hasn't thrown any codes until today, and today is was bucking to the point I thought I was going to call a tow truck, but managed to get it home. This is an 02 Quad Cab 4x4, bone stock with 103,000 miles, I am the only owner. I had some other work done, front/rear diff fluid change, oil/filter change, new serpentine belt, radiator flush/fill and new thermostat. I know the 1693 is a catch all, not sure what the others have in common. Forgot to say, my external ODB II reader says no codes are stored, key says otherwise, and no check engine light.

Dave

 

[Chief USA]

P1693 - DTC Detected In ECM Or PCM, P1698 - No CCD Messages Received From PCM , P0215 - Fuel Injection Pump Control Circuit, P0562 - Charging System Voltage Too Low.

I am leaning towards replacement of the VP-44 injection pump but before doing that, I think I would look into the low charging system voltage first in verifying proper charge voltage from the alternator. Something such as a bad battery with a shorted cell or other issue could be causing the low charging system voltage. I think I would troubleshoot the charging system also checking and verifying all grounding connections before doing anything with the injector pump. On the last week of the last month of my engine warranty, my injector pump threw a P0216 code. This was also causing bucking at low speeds when accelerating.

 

[DBeeman]

Thank you! I'm hoping that I got an electrical issue from the shop, at least I can fix that. I found it odd that my OBD II wouldn't read any of the codes. If it is the VP44, it will be #2, it will be my own fault for not updating the lift pump sooner, I will also have to see how difficult it is to replace myself, last one was under warranty and it was $2700 with labor.

Dave

 

[petersonj]

it will be my own fault for not updating the lift pump sooner,

Don't beat yourself up regarding the lift pump. There has been way too much emphasis over the years blaming low lift pump pressure for VP44 failures. If the shop didn't tell you what the lift pump pressure was while operating the truck on the highway, then they may have replaced a lift pump that didn't need to be replaced.

@Chief USA has given you some excellent recommendations - definitely look at your overall wiring connection conditions, especially grounds.

As far as lift pump pressure - a positive pressure at the VP44 inlet under all driving conditions is all that is needed. When Chrysler Daimler replaced my VP44 at 87,000 miles and retro-fitted an in-tank lift (all under warranty), that lift pump produced 6 psi at idle and 3 psi under engine load at wide open throttle. The low pressure readings didn't bother me at all. I drove the truck for over 150,000 miles with that setup and replaced the in-tank lift pump with a frame mounted used FASS lift pump - not because the in-tank lift pump failed, but because if the lift pump should fail, it would be easy to replace on the road.

I have currently logged 304,000 miles on the replacement VP44, all with lift pump pressure at 12 psi or less.

I will be surprised if you need to replace the VP44.

- John

 

[DBeeman]

So driver's side battery reads 13.88VDC with engine running, passenger side 11.30VDC with engine running. A lot of corrosion on both ends, going to replace it either way. Will do more wiring checks this weekend when I have more time. Going to disconnect the battery to clear the codes. So I hooked my scanner again, still said no stored codes, but when I told it to clear the codes, it did.

Dave

 

[Topzide]

That's a large difference in readings! You may need a new X-over cable with those values. Keeping cables clean and tight seems to be a big issue on our trucks! AGM batteries are worth the extra cost to cut down on the corrosion that develops on cable and connections under the hood. Noticed the difference on my '01 when I replace with AGM. When I replaced the 2 in my 2014, I sealed the connections with CRC battery protector. Whenever I have to pull them, I wire brush and reseal, to keep them tight and working well!

I hope that after you get things cleaned up and tight, you'll be ahead of the issue! Good luck.

 

[GAmes]

If both batteries are connected they should read the same voltage. Did you bypass the crossover cable somehow?

 

[LorenStrodtman]

Replace both batteries, clean all your grounds, and I highly suggest the W-T Mod. Once that is done, if the problem persists I would check voltage drops across your larger cables while a helper cranks the engine.

 

[DBeeman]

I'm going to replace the battery cables, the batteries are new. Will likely replace the alternator cable as well. Going to pull and clean every ground I can find too.

Dave

 

[DBeeman]

So far I have found a few grounds with higher resistance than I would call good, cross over cable is definitely in need of repair or replacement. This is going to take time as I need to pay off the $3200 shop bill on the CC first.

Dave

 

[LorenStrodtman]

So far I have found a few grounds with higher resistance than I would call good, cross over cable is definitely in need of repair or replacement. This is going to take time as I need to pay off the $3200 shop bill on the CC first.

Dave

The crossover cable is quite large to handle the massive amperage draw during cranking, and to some degree during the grid heater cycles. During normal driving, I would think it unlikely that a questionable crossover cable would cause enough voltage difference between the two batteries to cause "a slight surge at 35-55 MPH". I had some weird issues with my truck, and lowering the alternating current seen by the system resolved - as I recall now years later - all of them that weren't mechanical in nature (completely worn out injectors).

 

[JeepBuilder]

I fought dead pedal for 4 years. Replaced everything. ECM, VP44, TPS, alternator, and lots more. Id get 50 - 400 miles and it would return. After spending 4K on the problem doing my own work I found what causes dead pedal. Dirty battery cables and corrosion inside the cables themselves. I also did the WT mod and I have just topped 7K miles moving across wa state towing load after load. I am convinced dirty connections was the cause. My new wifes daughters neon POS car also started acting up recently. It had very dirty battery cables. Cleaned them all up and it runs fine now. I think Chrysler products like clean power. Get all that cleaned up and I bet you are good to go.

 

[Ozymandias]

Not only Chrysler, all of them.

 

[DBeeman]

Thank you!

 

[DBeeman]

Bought a new set of cables from Geno's, I swapped the crossover cable and eliminated the voltage disparity, both batteries read the same engine running or not, voltage with engine running is now 14.5 immediately after engine start, and 14.1 once everything has leveled off, voltage gauge in the cab is rock solid now too, never paid attention to how much it was bouncing around. Without a hydraulic lift, I don't feel comfortable with the starter leg, so I am going to try a different shop, and see if they can install the remaining pieces. Definitely not pleased with the work the first shop did. I have noted that some front end parts will need to be replaced in the coming year, all replacements will have zerk fittings.

 

[garylmoore]

Is there any chance that the surge you are feeling is the torque converter locking and unlocking? This is a common problem in dodge diesels at the speed you mention.

 

[DBeeman]

That was my first thought, but shop said the torque converter was not the cause. Codes pointed at comms and electrical. So far I haven't duplicated the anomaly since the cables were swapped.

 

[JeepBuilder]

My 01 quad cab is still running like a champ. I moved across the state and pulled load after load 4 hours each way. Not one hiccup. It was the dirty battery cables for sure. I hope truck owners with this problem can spot this info and not spend what I did chasing the dead pedal or hesitation problem. And funny on all the reports on several different diesel forums, nobody reported their fix. I did.

 

[Chief USA]

My 01 quad cab is still running like a champ. I moved across the state and pulled load after load 4 hours each way. Not one hiccup. It was the dirty battery cables for sure. I hope truck owners with this problem can spot this info and not spend what I did chasing the dead pedal or hesitation problem. And funny on all the reports on several different diesel forums, nobody reported their fix. I did.

Just my humble 2 cents worth.

If you have not paid the shop back , I think it only reasonable and common sense to take your receipts and evidence of what you did to repair the issues that the shop SHOULD have found & completed and talk to the owner or supervisor to see if you can negotiate some or most of the bill down to a reasonable price. Yes, shop time is money, but if they didn't do anything or very little for you, they should not have charged you or at least only charge for the isses they actually repaired.

 

[JeepBuilder]

Just my humble 2 cents worth.

If you have not paid the shop back , I think it only reasonable and common sense to take your receipts and evidence of what you did to repair the issues that the shop SHOULD have found & completed and talk to the owner or supervisor to see if you can negotiate some or most of the bill down to a reasonable price. Yes, shop time is money, but if they didn't do anything or very little for you, they should not have charged you or at least only charge for the isses they actually repaired.

Maybe your message was intended for the original poster. If not....
I do all my own work. No shop will touch my truck. Granted I had the drivers side repainted and I wished I had done it myself. Places like Oregon fuel injection rebuilt a VP44 for me. That is about the extent of subbing out work. I prefer to do everything myself every time. I am set up for just about everything. So I can only blame myself for all the new parts when all I needed to do was open my eyes and see the poor condition of the battery terminals and corrosion. They look good now.