sosborn

I thought I had a bad Cam pos sensor. I had the codes and the dropping tach. Took it in and got a call today saying I have a bad ECM.
After doing a little research on the board, it appears like they could be right; the truck did actually die on me several times, which shouldn't happen if it is merely a bad sensor, right? Anyway, are there any other symptoms that would confirm a bad ECM? At the moment, the only symptoms are the tach going to zero and the truck dying.

The truck is a 2001 Quad cab 4x4 5spd

I also get gas mileage that is lower than what seems to be average. 15-16 mixed driving. I am assuming a bad ECM could cause that as well?

Anyway, I just wanted to get some input before I dropped 1,230 bucks on a new computer.

Oh, and I just bought the thing four weeks ago. Any tips on how to get the dealer to help pay for the fix? I payed a price that assumed the vehicle was in great woring condition, which it is not.

Any help is greatly appreciated.

Thanks,
Sam

BarryG

You should be able to get another ecm used for significantly less than that like 1/2 or less. Check on here for member Bob Wagner, maybe under bwagner he sells the catcher ecm and he needs cores all the time and I think he can get you one for a decent price. Then all it needs to do is be reflashed which the dealer is going to have to do anyway with the new one.

newriverSpecon

Or go with a MAD ECM! I think they are sheaper then $1200 without core.

Randy

RowJ

Sam, Welcome to DTR!
Bad ECM is almost unheard of? Anything is possible but just have never heard of it.

If it's a Dealer your talking to, $1230.00 is a fair discount on a NEW VP-44 pump...but not his cost....which is what I would expect, if I just bgt the truck from him.
I was offered that price from my dealer's Parts Dept. when mine died. I have bgt stuff from them but by no means am I a big customer!

As mentioned above...you can get a MAD ECM from Bob Wagner for about $400.00 less (NET). Lots more performance & less expensive!
http://www.wagnerandassociates.biz/

Where are you located....Mileage may be about right if your having to buy Winter Fuel and your city driving is real stop & go, big city type.

Hope that info helps.

RJ

John Faughn

I 2nd that on the unlickly hood of bad ECM , not comin, you may want to get a 2nd opinion, when I'ld find a bad ECM [ most often GM] I would also find out what made it go bad , becouse if that isn't fixed then it will kill the new one , and maybe not right away , and try to get them to put in a nother one a monthor so later, the 2 most comin things to kill a computor is you lose a ground and then the ECM finds the next closest one and that ends up to be internal and thats kills it , then the next is any of the actuators [ there are 3 parts to a computor system in a automotive apllicaion , sensors telling the ECM what the conditions are , from that the ECM make a decistion baced and the progarm , and then uses the actuators to perforum a function] when the actuators have a coil or relay and they short out that can kill the computor. Hopefully my computors bad spelling will not cause you any problums.

cm

Bob Wagner

Is your wait to start light functional ? and yes we have replaced several bad ecm's this year.


no wait to start light = bad ecm

sosborn

Yes, the wait to start light works. Comes on for a while (varies with outside temps) and then goes off.

Is it possible that a bad cam sensor would cause the truck to die?

In the spirit of more info, Here's the history since I bought it four weeks ago. Nov. 19th the tach died and it posted a code - p0341 (i think, either that or 0340), but didn't die. It did the same thing last monday, so I had Auto Zone pull the code to confirm the Cam sensor and I was going to get a new one and pop it in, Before I could do that, last tuesday(31st), the tach died repeatedly, it lurched on acceleration, made it down the road about a mile, started lurching again, and died. I got it off the road and let it sit a while, trying to start it a few times, but it kept dying. Let it sit about ten minutes, and it fired back up and got me the 1/4 mile down the road to the dealer, where it has been until their diesel guy got back into the shop. Got the call today about the bad ECM.

RJ - I'm in Zanesville, OH, been cold for a while, so I was thinking the winter fuel had something to do with it, but had not confirmed the type of fuel yet.

The $1230 included everything - diagnosis, parts, labor, and tax - still much more than what I thought I would drop for a cam sensor. Bob, in line with what you would charge?

So here's another question - why would it have thrown a code for the cam sensor, if its the ECM that is bad? If the ECM is bad, could just be confused?

Thanks for the help guys. I love this truck - i need my baby back!!

Sam

sosborn

One more thought - shouldn't there be a code for the ECM failure if that is what it is?

smokindog

I'll have to agree that is unlikely the ECM. The symptoms you describe could be quite a few things.

The cam position sensor is behind the injection pump and I couldn't imagine trying to change it with the pump in place. I didn't look in the service manual to see if it can be replaced with the pump in place as I swapped mine out when I was replacing the VP44 anyway.

MCummings

It is really soounding like a cam/crank position sensor.

Low mileage, random driveability issues, shutting off. Replace the sensor, and THEN, IF NEEDED replace the ECM with a MAD ECM.

Get with Doug @ www.smokindiesel.com or Doug @ www.PerformanceDieselWarehouse.com

Doug's just seem to be good people I guess, LOL.

Merrick

J BODY

I've been a dealer tech for eight years at my current location and have only replaced ONE ecm on a Cummins. I would diag until I was blue in the face before I condemed a Cummins ECM.

taken5875

Any one have pics or diagram of all the ground locations

jrs_dodge_diesel

The four usual symptoms of the crank (CKP)/cam(CMP) sensor going bad are:

Alternator output to zero, the truck will be running solely off the battery.
A/C clutch will not engage
Tachometer will read 0 RPMs
P0320 code - No crank (CKP) reference signal at PCM. P0340 and 0341 are the CMP codes

The CKP signal goes to the ECM first. The PCM then recieves the signal from the ECM. Losing the CKP signal will not shutdown the engine, mainly because the injection pump is timed to the engine itself and the FCMP. Here's some info from the service manual about it:

"The VP44 is controlled by an integral (and non-servicable) Fuel Pump Control Module. The FPCM can operate the engine as an Engine Controller if a CKP signal is not present."

What is interesting to note, on the gas engine Rams, the PCM will shutdown the engine if it does not get a reading from the CKP. Not the case with the diesel Rams because the PCM has no control over the fuel systems.

It does sound like sosborn has some deeper issues with his truck, but the CMP/CKP sensors are not causing his problem. His tach dropping out sounds like it's the sensors, but that alone will not shut down the engine. The tach signal goes to the ECM first, then the PCM. If the ECM drops offline, then the PCM will lose the tach signal. It sounds like to me that there is a partial failure in the ECM.

high bid

Watching thread
Tach going to zero, cel comes on and truck begins to lope/run rough. I pulled over shut it off for 5min. Tried to restart and LP would not run...even w/bump start....after 4x. Disconnected (+)batt and adrenaline...let things sit for 1-2min, reconnected batts and it started.
I've replaced the crank pos sensor (behind the starter) about 2yrs ago....can't imagine it going out again. Any input would be appreciated.
Will take it to autozone to pull code in the am