Hello all,

ok so I am trying to fix my girlfriend's truck.... here's the story;

the truck starts and idles just fine but when you step on the accelerator, the rpms jump from 800 (idle) to about 1400. the rpms will stay at 1400 regardless of pedal position until you completely lift your foot off the pedal at which time the rpms drop back to 800... so it's either 800 rpm or 1400 rpm, no inbetween and nothing higher.

when the truck initially broke down she took the truck to her mechanic whom replaced the apps which resulted in no change in engine performance

she then took the truck to a garage her mechanic recommended. they scanned the codes and came up with two codes, p1689 and p0232. after getting these codes they told her that she needed a new ECU but that they couldnt find a new ECU for her truck so they sent it off to have it rebuilt. they put the "newly rebuilt" ECU on the truck which resulted in absolutely no change in engine performance... then they told her that she needed a new VP44... at this point I told her to have it towed back to her house and I would work on it myself

ok so I have been researching these codes and everything I have read about the p1689 indicates that it is a wiring problem and NOT a VP44 failure and from what I gather the same holds true for the p0232 code in the sense it is a wiring issue and not a mechanical failure... I have yet to see a thread anywhere that included both these codes showing up on the DCT so i'm wondering if one problem might be causing the other... can anyone clarify/verify this?

the biggest problem I am having with trying to test wiring is I am unable to get my hands on a vehicle specific wiring diagram. does anyone have or know where to get a good schematic for a 99 dodge 2500 4x4 cummins turbo 5.9?

I would appreciate any help I can get

 

Sounds to me like you've got some wiring issues under the hood.

The 1698 might just be a bad relay. 0232 might be aswell, Try switching around some relays under the hood, and seeing if that help.

If you narrow down what diagrams your looking for, i can post up some.

Some of the notes I've found in accordance to the codes

FUEL INJECTION PUMP RELAY-ECM OUTPUT
The Engine Control Module (ECM) energizes the electric fuel injection pump through the fuel injection pump relay. Battery voltage is applied to the fuel injection pump relay at all times. When the key is turned ON, the relay is energized when a 12-volt signal is provided by the ECM. When energized, 12-volts is supplied to the Fuel Pump Control Module. The Fuel Pump Control Module is located on the top of the fuel injection pump and is non-serviceable.

The fuel injection pump relay is located in the Power Distribution Center (PDC). Refer to label under PDC cover for relay location.

SYMPTOM
P-1689 NO COMMUNICATION BETWEEN ECM & INJECTION PUMP MODULE (OBD II)

WHEN MONITORED
Ignition on.

SET CONDITION
Time between CAN messages > 3 seconds or Fuel Injection Pump Module does not receive CAN message.

POSSIBLE CAUSES
Fuel Inj pump Gnd ckt open or high resistance
Fuel pump ctrl mod harness observable defect
Datalink (+) circuit open
Datalink (+) circuit short to ground
Datalink (-) circuit open
Datalink (-) circuit short to ground
Engine control module defective

---AutoMerged DoublePost---

SYMPTOM
P-0232 FUEL SHUTOFF SIGNAL VOLTAGE TOO HIGH

POSSIBLE CAUSES
Engine control module defective

 

man I really appreciate the ECU pin ID diagram and the ECU schematic, those are a tremendous help.... thank you so much

I am going to run a few wiring tests today. as for the relay, I need to find a PDC label as the PDC cover is MIA so I have no clue what is what on the PDC.

can anyone tell me if alldatadiy.com is a good site to use for troubleshooting and schematics?

 

that's what i linked.. was alldata stuff... but its alot of money to purchace the subscription..

I will see if i ican't find the PDC chart

---AutoMerged DoublePost---

 

yep I know the alldata subscription is pricey but they have an "alldatadiy" subscription which is only 26 bucks a year for a single vehicle... I was just wondering if the diy subscription would be as informative

I am trying to run down a pdc cover from a junkyard but haven't had much luck finding one with an intact label

anywho, thanks again tweaker, you've been a great help

 

ok I ran wiring tests...

I have a good solid ground at the IP as well as pins 30 and 49 on the ECU. I have about .1 ohm resistance on both datalink + and - wires (terminals 1 and 2 on the IP and terminals 13 and 23 on the ECU) and I have 12.26v at the IP... I also tested the datalink shield wire (I forget exactly which pin it was but i'm thinking it's pin 46 on the ECU) for a short against the datalink + and - wiring... I have not found any open or shorted connections in any of the wiring...

I can only assume the CPU on the VP44 has gone out since I haven't found a way of testing it and the p1689 is now the ONLY code i'm getting.... so a new IP, filter and lift pump are on the way

 

yep sounds like you got it figured out...dunno how many times i've checked the wiring on them and find out its just the board on the pump

 

new vp44 installed.... still doing the same thing

grr... 2 grand in repairs so far and still not fixed

 

If you are still looking for service info, someone on this site pointed me to Geno's Garage for factory manuals. They have the one for your truck on cd for $120. I know that is a fair amount of money but it is the chrysler factory manual so the info is complete for the truck. I got one from them for our 92 and was well satisfied. It will probably save more than it's cost over the long run. Dodge Factory Service Manuals-Dodge Cummins Diesel Truck Accessories – Geno’s Garage

 

on a hunch I called the company who supposedly rebuilt the ecu (modulemaster.com) and talked to the tech who performed the "rebuild". as it turns out, this company does NOT do ecu's, they only do ABS modules. the tech told me that the only thing he did was break it open and check for cold/broken solder joints so at this point I am ready to someone over the head


so I have been searching for an ecu and can't seem to find one. can anyone tell me where to find a rebuilt ecu or what the chances of a junkyard ecu actually working would be?

---AutoMerged DoublePost---

I read somewhere in these forums that Bob Wagner was the man to talk to about ECU's. however I can not pm him as my post count needs to be above 10. and I am not one for spamming. so could someone please put him in touch with me or direct him to this thread?