Dead Pedal

[RPM]

I've got a new one. I have the following codes; 0112 Intake Air Temp Sensor voltage low, 0230 Lift pump circuit out of range (This doesn't surprise me much as I took off the electric pump and have been running the mechanical pump for a few months now. Maybe I should have did something with the wires instead of just unplugging them), 0237 Manifold Air Pressure sensor voltage low, and 1475 Aux 5 volt supply voltage hi. The dead pedal affects the top speed. My acceleration sucks and it tops out about 55/60.Now I have heard 1475 is one of the codes that shows up when the ECM takes a dump but it accompanies codes from all the sensors and the alternator starts putting out crazy numbers. My alternator is charging at 14 volts and I just have the two sensors. Also The sensor voltage is low and the 1475 is the high side.A mechanic I know says Dodges have had an issue with the AC hi side pressure switch goes out and takes out the other sensors along that reference string. Since I have never heard of such a thing. I will check that tomorrow. Anyone have anything with this set of codes? And anyone know where the error code reference went? I can't find it.

[gassernomore]

Here you go: http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes .

[Homestead]

I actually just went through this with almost the exact same codes and it ended up being my ECM cooked itself. Driving home one day as usual, shifted up to the next gear and poof, dead pedal. I managed to get it going by slowly applying the throttle to get it up high enough to engage the cruise control and managed to get it home.Changed out the APPS and every other sensor on the truck and no go. After chasing the harness and doing every probe test I could to chase voltages, it was obvious that the ECM puked.$2500 later she was as good as new. It went to the dealer only because I work out of this truck, when it is not running, I'm getting poor. Dealer had it done in 2 hours.All the sensors are run off the same feed, the ECM monitors the readings, when they start going high and low, it's internal.Jeff

[98whitelightnin]

Been through this with a buddies truck. Your problem is with the 0237 cade, its a map sensor code. Unhook the xzt and see if it changes, if not, replace the map sensor and it will run good again.http://www.genosgarage.com/searchprods.asp

[RPM]

I unhooked the XZT today, without any change. I have 5 volts at each of the sensors when connected. No change in voltage when they were disconnected. Still have the same codes. Tried the AC pressure switch thing as recommended by my neighbor, and no change.

I like the MAP sensor idea a whole lot better than a new ECU. Hope I am not throwing good money after bad if I start changing sensors.

[dripley]

When my ecm went i had high and low voltage codes on darn near every sensor on the truck. I could not believe they alll went at once and it did turn out the ecm was bad.

[RPM]

That's what I have heard, when the ECM goes it shows a code on almost every sensor. I will swap the two and see what happens. I also downloaded the testing sequence from the error codelist last night. I will spend some quality time with my multi-meter this week.

[Mopar1973Man]

With a failed ECM the voltage will be all normal but the live data from the OBDII port will be one extreme or another. As for the limited throttle response CajFlynn had a ECM fail and cause the same thing.As for the AC high side switch its not even connected to the ECM or engine wiring. The AC hi and lo switch is connected to the PCM.

[dripley]

My truck was undrivable when mine went out. The engine was surging on its own. The throttle response was slow and would just keep going higher in rpm no matter where you held it and some times no response at all. The temp gauge would peg 15 to 30 seconds after a cold start. I replaced that sensor with no change. The voltage coming from the sensor was working properly but the ECM was not seeing it properly. I even replace the instrument cluster because the diagnostic I ran on it said it was bad. No change with that either. I am definately not an electronics expert, I just knew in my heart that there was no way everything went out at once. A reman ECM soved my problem. I am not saying replace it, some testing is in order before spending that kind of money.

[RPM]

Ya, I'm not there yet. The truck just runs at a decreased level of power. Really no jerking and the gauges are working fine. Starts the same, throttle responds the same, but just stops about what I would estimate to be 1/3ish of the top end. Slow to build boost and only those two sensors showing as having a voltage problem. I would like a scan gauge to check the live voltage like Michael said.

[RPM]

Well I changed out the IAT and MAP sensors and it still shows the same codes. I couldn't clear them with the code reader. I don't have a scan gauge, and my code reader will not let me see the live data. I disconnected the batteries for a day and cleaned off the terminals just to be sure, same results. I again unplugged my XZT and no change.

I am thinking this is the death nail for my ECM. With Christmas on the horizon, I really don’t have $1500.00 to give Dodge for a new ECM. I don't have the time or money to spend on shoddy reman either.

Can someone give me some leads on where I can get a quality ECM for cheap?

[Mopar1973Man]

find one from a salvaged truck and have it reflashed that has been know to work.

[98whitelightnin]

Is it still running bad? The codes will erase themselves if you fixed the problem.

[dripley]

The bad thing about a bad ECM is, no matter what you fix the ECM cant see it and still thinks everything is bad. At least that was my experience. IIRC Cajflynn has had some good luck with a rebuilder of ECM's. He would have to tell you who. PM him and see what he has to say.

[RPM]

find one from a salvaged truck and have it reflashed that has been know to work.

Finding a Cummins truck in a junk yard around here is pretty difficult. I think I would have better luck with the lottery.

Is it still running bad? The codes will erase themselves if you fixed the problem.

Yes, my code reader says it will not go over 40% load.

The bad thing about a bad ECM is, no matter what you fix the ECM cant see it and still thinks everything is bad. At least that was my experience. IIRC Cajflynn has had some good luck with a rebuilder of ECM's. He would have to tell you who. PM him and see what he has to say.

I will try that, thanks.

Any other suggestions? I have read the threads that say the ECM is incredibly hard to kill and I wonder if I am missing something. On the other hand there seems like enough people have had issues with the ECM as well.

[RPM]

I was able to get under the hood today. I checked to see if I had any shorts in the sensor wires, no dead shorts. I checked the impedance between the sensors and the ECM plug, all seem in the same ball park.I took out the ECM and checked to see if all the grounds were interlinked or if there was a short between some other pin and a ground. I have good continuity between all the ground pins. I do not have continuity between the grounds and any other pins.

One thing I found is I have continuity between the case of the ECM and pin 42 (Cummins Bus Shield), and pin 44 (Data Link Shield Inj). No continuity between the case and any other pin. I do not know if this is a problem or not.

Is there something else I can check while I have the ECM out? If I take the ECM to Cummins can they test it? One last question, can someone tell me why I have just one wire going to my oil pressure sensor?

[RPM]

Progress, or lack thereof report. I checked the running voltages today with the help of a pin and my DVM. The voltage at the MAP was right at 5.01 volts and never wavered. I unplugged one sensor at a time to see if any of the codes would change. The only thing that happened was the sensor I disconnected would code. When I plugged them back in they all cleared.

I am getting to the point that I don't believe it is the ECM but for the life of me I don't know what the heck is going on. What is the chance I got a bad MAP from Geno's?

[dripley]

I replaced my ECT sensor since it was the one going the craziest. I would start the engine and let it warm up. I monitored the sensor while the engine was warming and watched it perform properly, but the gauge would peg out inside of 30 seconds. I was also seeing good voltage at the other sensors, but the truck was still not dravable and the codes kept telling me the voltages were too high and too low. It might be time for a trip to the dealer and have them check it. Mine was so screwed I felt it could not be anything else but the ECM.

[RPM]

I am not getting any changes in voltage no matter how long it runs. I called the dealership today and they told me they can diagnose the truck for 47 dollars. I am just not confident if they will really let me know what the problem is or not. Another problem is, I am running up against my plates expiring and I need to get my emissions. There is no way they will test the truck in limp mode. Quite frankly, with as much hair as I have pulled out since this has started, the 47 bones would be worth it.

[Mopar1973Man]

Tend to agree...