2002 Dodge Ram 2500 starting Problems

[mjmplus]

Well the repair shop called me and said the problem was the alternator was overcharging the system and frying the ECM they said $2400 to replace both haa haa haa. They said the power output to pin 5 sensor ground in the odb2 port was caused by the overcharging, would that be true?

 

[SportRam00]

The alternator should be running at about 14 volts to keep the battery charged.... Did you notice any voltage spikes on your gauge cluster while driving the truck around?

I would think if there is any voltage on a ground, that would signal a poor chassis ground connection which could lead to an overall build up of electrical charge on the whole system which could fry the PCM (just thinking logically here). Again, this seems more like a ground issue than anything else, but I'm not a trained mechanic. I have read in the past that 12v+ fed back to certain pins on the PCM = PCM death....

PCMs are expensive and chances are you would receive a reman unit ($200+ online), which can have their own set of problems. Alternators run about $160 online. His labor rate is ridiculous since neither part really take all that much to install, although the truck would need to be hooked up to the diag computer to "configure" the PCM with your VIN and mileage...

I guess it comes down to how much you trust this guy! But it sounds like he is really hitting you hard on labor and parts markup.

 

[JohnnyMac]

I wouldn't do it man. Those clowns are just Easter egging. They'll swap out the PCM because it's easy and they make a load of money, then when that doesn't fix it, they'll say "Well it looks like you have another problem in addition to the bad PCM" when actually the PCM was good to begin with. If it was doing this before and you sent it back to the repair shop and they tested it good, then I'm betting it's good now. Seems to me it's a bad ground, a shorted wire or the charging system (battery/alternator/voltage regulator) that causes the PCM to freak out.

 

[mjmplus]

I didn't really check for voltage on charging system. opps. This was taken to a dodge dealership service center ( why price so freaking high ) They said alternator was output almost 18v. But when they unplugged the alternator and started the truck they said truck would run only when a code scanner was hooked up to odb2 port, but truck would eventually die. I even told them watch the cable for code scanner it will get really hot and melt. Yeah, i thought price was way to high, so i told them nope and had it towed back home. So far waiting for a rebuild kit for alternator and gonna go from there. Still checking on weather i need another ecm or not. They charged me almost $400 for diag and still didn't tell me, had to read it on paperwork, that after replacing those parts, would still be check for maybe other problems. What kind of diag is that, suppose to find all problems for that freaking high of a price, when i bet they didn't do 2 hours on diag and still charged me 2 hours. I think maybe which i have looked that all the starting problems i may have repaired and the ground somewhere is something new, esp. sense i like an idiot went to pull starter and check dust plate on tranny for the noise i was hearing. I forgot to pull neg cable off battery and you should have seen al the smoke from the grounds i had to replace melting. But still i searched everywhere for ground wires and replaced all that i saw bad or melted. Probably missed one somewhere. ( also on ecm repair and i wrote the people that repaired it, why did you cut a circle over eeprom chip to repair cold solder they said they found. They glued it back on, the metal they cut for easy servicing. I heard that cutting that hole made the heatsink on main casing not good. Never got a response. ) Thanks all

 

[mjmplus]

Looking for what interchange number i can use on this truck for the ECM The ECM is P56040206AC

 

[SportRam00]

This PDF has some good information on PCMs: http://starparts.chrysler.com/starlibrary/marketing/reman/Electric.pdf

 

[mjmplus]

Thanks, I am only showing 1 reman part number I can use in this pdf. I was hoping there would be more that would work. I looked up costs of compatible ecm and damn they want min. around $500.00

 

[SportRam00]

Wow! Yea, PCM's are EXPENSIVE. For my 00 a reman ran about $300. Luckily I was able fix my problem with a little luck.

 

[mjmplus]

Would any one know where i would start to find and repair my ECM that is sending voltage to my ODB2 port pin 5 sensor ground. When i remove c3 connector on ecm the power to the pin 5 goes away, it's reading 7.74v to that pin. That's making me think the voltage is coming from ecm because of ? (who knows) !!! Thanks

 

[SportRam00]

I would refer to the factory service manual for your year of truck (should be available for download on this site) start with the wiring from that plug through the wire loom. It could be two wires rubbed bare against each other and the voltage is jumping to a wire that it isn't supposed to be on. Verify all the wires on that connector are good before digging into or replacing the PCM.

There is a link to the 01 service manual in the DIY section. Hopefully that helps, however since you're an 02 I'm not exactly if the wiring diagram will exactly match up. Look for any wires that carry voltage in that connector and trace them out. It's a pain, but you might find your problem. Only after you do that would I consider dropping that kind of cash on another PCM.

 

[mjmplus]

I have bought a refurb ECM and the truck started right away, even though i did not get the vin programed to it. But the truck died within 15 sec. I did find a o2 sensor that had melted wires and removed it. No help, now no fuel pump kicking in again and will not start. Also noticed that when i hooked up refurb ecm the power going to pin 5 obd2 port is gone, but now something else weird, the pin 16 main power to the obd2 port shows no power. Have checked all o2 sensors and they look good. O2 fuse under hood still shows less than 8 volts, it even shows with test light power going to both sides of where the fuse goes without the fuse in it, thats not right.......... Still searching wires and , almost ready to lose almost $8000. on this truck, just to get rid of it.