jaconst

ok I didn't know that about the gauge pegging 240* when disconnected. I looked into what the A/C transducer fitting is and those wires are soft (from oil) and touching the steel coolant pipe (rubbing) that goes to the trans coolant tank on the turbo side of motor. I seen somewhere where that is a 5v sensor. and I think it may be touching those 2 together Im going to try and disconnect that and take those wires independently

Busboy

Note a digital volt meter might not show an intermittent fault as it samples and does not read real time, you need to use an analog one.

drewk88

While thinking about this problem further, it occurred to me that if the 5 volt supply was being taken low by a short, the coolant temp gauge would read low not high. So maybe the problem lies in the ground return to the ECM.

You should check to make sure the ECM connector plug is not loose.

jaconst

ok I checked it and its tight and doesn't look damaged or anything out of the ordinary. I guess Ill probably take it in to someone to check over everything Im out of time to work on it.

jaconst

well I took the ECM plug off and checked it out nothing was corroded or wet or looked damaged. still running Limp mode. I had a guy look at it and he wanted to trade me his 96 dually cummins but it was pretty beat up in my opinion it ran great shifted right ect NO rust but he wanted a straight trade and $200 for my truck and the edge box I decided against it.
Im thinking of possibly taking it to dodge dealer close by usually wouldn't choose a dealer but this dealer does primarily deal with cummins and sells a lot of them and also they will give me a loaner car in the mean time. I don't know just want this to be over losing patience

rickf

Have you checked for A/C voltage leakage at the alternator? I hate to tell you this but with today's vehicles you need to have both a digital and an analog voltmeter to diagnose just about any drivability problem with any vehicle. 90% of those problems will turn out to be bad grounds somewhere in the system and another 5% will be corroded wiring where someone has cut the insulation for one reason or another. Boat trailer wiring, accessories under the hood and dash. Anything that compromises the insulation invites corrosion and that in turn builds resistance in the wire which will wreak havoc with low voltage signals. Bad diodes in an alternator will not show up o a normal charging test but if you check for A/C voltage then you will see a reading. That can raise hell with the computers. You need to go to the FSM and follow the trouble shooting tree, if you jump around, as you are doing, you will never find the problem.

Rick

jaconst

FSM? not familiar with that.
so would replacing my alternator help or are you thinking its wiring harness related? I'm thinking my best bet is taking it to a reputable place that has experience with cummins. I'm not a mechanic but I can do a lot of mechanical fixing, I'm just tapped out spent this last week on it and need to get back to what I do best and pays the bills. I'm going to have them do diagnosis and if it is the ECM then I will get one and probably fix myself. I have heard so many conflicting theories and chased them also. I have heard guys that work on them or have had similar problem by the truck load (pun intended) some say the edge fries ECM's so to say the least I'm out of patience. Thanks for all the help on here everyone Thank you I do appreciate all ideas and help. I do know the alternator has been saturated with oil from the amsoil relocation oil filter setup near it so That does make sense except my gauge always shows plenty of volts 14-16 running, but one of my codes was charging system too low after I replaced batteries. It would be great if it was just an alternator as I can change that in little time and for around $100

jaconst

well I removed the alternator took it in (as a core) and thought they should test it first. They tested it and everything came out normal, diodes, charging, ect. And I was talking with counter guy and he told me about a really good small independent diesel guy actually just a few miles away from me, so now I have a good local guy to boot.

Anyways I told him my problem and troubleshooting I have done and he said that He had an 02 in before that did same kind of problem I had and it was the Map Sensor and that it was updated with a wire harness as well because they don't make OEM anymore.

Well I called dodge dealer who specializes in cummins and they said its $280 for map sensor and $49 for wire harness I was like what? and on top of it because it was after 1pm couldn't order it til tomorrow as its coming out of Chicago so they would see it Wednesday afternoon. And he didn't call it a map sensor kept insisting it was a different part Boost sensor.

So when I got home I looked it up in my Geno's garage catalog and what do you know Map sensor $88.95 and wire harness $18.95 so I called them and it was a little after 5pm there time and he says UPS will be there any minute. But he just gets the order done in a flash says Ill have it tomorrow by 10:30 am for $33 shipping so total $141 with shipping $200 less than dealer and this isn't the first time they saved me $$ time and piece of mind.

They are hands down absolutely the best and I am a customer for life and any other diesel guy is going to know about them because I will tell everyone I know.

mslashbar

I posted a few days ago with the same problems as you have. I went ahead and took it to cummins, they said it was the ecm. They don't have it in stock but it should be here tomorrow. $1150 plus $150 to program it. They put on a test ecm they had and said truck ran fine. I should be getting it back tomorrow and will let you know. I was a little afraid of going with the other places that repair ecms after reading some of the stories on the internet. A few have had good luck with them, but lots had nothing but trouble. I need this truck for work, and don't want to be taking a gamble with some of these rebuilders.

jaconst

well I guess It wont hurt to replace my map sensor if it works great if it doesn't next step is ecm although dealer and cummins told me an ecm was 1300 for part plus flash program ect it was going to be 1500-2000 vp44 would of been cheaper at that rate I don't know where else to go if that's the case. let me know how it goes thanks

jaconst

Installed map sensor and jumper wire set and it does run a little better but still occasionally pegs temp gauge and diminished performance mode but not all the time. Also what's weird is code P0217 Decreased Engine performance Due to Engine overheat condition is gone but now code P0113 is present Intake Air Temp sensor voltage to high. So now my intake air temp sensor voltage is both to high and to low

Busboy

I believe the ECM regulates the sensor voltage output at 5 volts, if there is a short that tries to drop the voltage the ECM increases output to maintain voltage then when it un-shorts the voltage is then too high so it decreases output, up down kind of thing. I would still look for that shorted sensor wire.

mslashbar

I finaly made it up to cummins and got my truck back today. New ecm and everything seems to be fine. A couple of different people told me if you get the p0606 code to disregard all the codes after it. If the ecm is bad it will set off all kinds of sensor codes. Also my temp gauge was going nuts, works fine now without doing anything but the ecm.

rickf

The output is 5 volts constant, it will not change. What will change is the sensor value seen by the ecm due to the short. Also the ECM may shut down an entire bank of outputs if it senses a short to protect itself. I am not real familiar with the Cummins ECM but most of the automotive computers are set up this way.

jaconst

well I drove it today about 25 miles and it wasn't real bad just annoying I even was able to maintain speed limit speeds 40-60 mph most of the time with just some sputtering mainly from stop signs. I decided to take it into a local truck (only) repair place. see what they say tomorrow. I originally went to a dodge dealer that deals with lots of cummins for the loaner car use but they didn't have any so I guess that made my decision so I went to a close by shop. ill keep you posted