Doesn't the ODO show NO BUS when it isn't getting a signal from the pcm? could this not be a connection or connector with a bad connection to the board cause this? I'm not sure about the 2000 models but might there be a problem with the connection at the back of the ODO or if there is a connection at the PDC that has a bad connection.
I don't believe that your shut down and your smoking issues have anything to do with each other I would start the truck and start wiggling the relays and connectors to see if it would shut down.
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well im not worried abotu teh smoking issue, but my no bus only occurs when the truck shuts down, but works every time, all the time. unless it decides to shut off. then it flashes 3-4 times, then reads no bus, then i turn the key off and back on, and it works again, though it still doenst have any power, as my gagues stay at zero when its off.
and ive already twisted the terminals on the fule pump, and asd relay as well to make better contact and it seemed to fix the problem, but then it died again, so im at a loss here.
Like you stated, it's an intermittent problem and, these are the toughest to troubleshoot. It's easy when something is not working as you simply can root it out. However, in this case, this is going to be a really difficult case to diagnose.
So, let me get an understanding of what is going on here. It appears that we have an auto shutdown type of event occurring and, it occurs only when the vehicle is powered off. Is this correct?
It appears to me (after reading this post again) that you have a vehicle that without warning, powers down.
What I am getting is, it does this both when the truck is shut down and also when it shuts off at random. There's no set pattern or set conditions for this event.
We also have an easy start up after this event occurs as well as a hard to start condition.
We also note that you have a CCD bus issue.
To diagnose this problem we map out mentally or on the whiteboard the basic level of what is involved with an auto shut down and list those out:
- ASD relay
- Fuel Pump relay
- Battery Temperature Sensor
- CKPS
- CPS
- CCD bus on the PCM output
- Battery Voltage
- Generator
First thing I must ask: Do you own a DMM or DVM such as a Fluke or similar?
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96 Dodge Ram 1500 4WD, Hughes Fi Airgap, Custom Al -6AN billet fuel rails, Bosch FIs, JBA headers/ JBA perf. exhaust, F&B TB, Summit- -6AN fuel supply lines, Magnaflow hi flow CAT, Pulstar plugs, Moroso Ultra 40s, SCT, MSD coilpack, Volant CAI / Kenwood Excelon XVT 819 DVD, Alpine PDX 4150, Kenwood KAC-X10D, Boston Acoustics, single 10.
Last edited by cmckenna; 11-08-2009 at 12:47 PM.
Reason: Clarity in questioning
[quote=cmckenna;1868863]Like you stated, it's an intermittent problem and, these are the toughest to troubleshoot. It's easy when something is not working as you simply can root it out. However, in this case, this is going to be a really difficult case to diagnose.
So, let me get an understanding of what is going on here. It appears that we have an auto shutdown type of event occurring and, it occurs only when the vehicle is powered off. Is this correct?
Autoshut down is correct however it happens when the motor is running, i dont leave my ignition on without teh motor running, as ive burned contacts in the switch in a previous vehicle by doing that.
It appears to me (after reading this post again) that you have a vehicle that without warning, powers down.
correct
What I am getting is, it does this both when the truck is shut down and also when it shuts off at random. There's no set pattern or set conditions for this event.
Nope, I just shuts down at random, and the no bus only occurs after the truck shuts down.
We also have an easy start up after this event occurs as well as a hard to start condition.
Sometimes yes, it starts right back up with no problem, however 8 out of 10 times its a hard to start issue, that i have to go unde rthe hood and swap relays, unplug the pcm and replug it back in.
We also note that you have a CCD bus issue.
Only when the truck shuts down. However im not concerned with the no bus issue as it only happens when the truck shuts down, and it is my understanding that when it shuts down power to the pcm is killed, and thus giving me the no bus reading, and once i get the truck running again, everythign works fine, with no problems.
Or if i turn the key off then back on, My odo works for a few seconds then
To diagnose this problem we map out mentally or on the whiteboard the basic level of what is involved with an auto shut down and list those out:
- ASD relay
- Fuel Pump relay
- Battery Temperature Sensor
- CKPS
- CPS
- CCD bus on the PCM output
- Battery Voltage
- Generator
First thing I must ask: Do you own a DMM or DVM such as a Fluke or similar?[/qoute]
Yes I do own a few of them though not a fluke meter.
im not sure if this could be the problem. is it possible that wires are touching, causing something to ground out? but its barly touching becuase you can start it again. and maybe (while truck is running) since it has more voltage going through, its causing the short. and your able to start it again, because all the power is not at the wire anymore.
Not sure if you understood this, but it seems logical
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95 DODGE RAM 1500 5.9 4X4 SLT Shortbed, New Tranny, Suspension, 4.10 Rear End. Straight Piped, New Rims. Hughes Plenum. Sony Xplode 1000w, with 10in. Kicker L5
5.9L Club Forum Member #39
Well the problem is When i thought i fixed it by cleaning the crank sensor, it ran fine without shutting off for almost a month. so I dont know when/if it will shut off, sometimes ill be runnin 55 down the hwy, 75 on the interstate, 35 on a side street, or even stopped at a traffic light. I just dont know, when/if it'll shut off. and from my expierence there has been no correlation between each time its shut off. and no codes present or stored as check with my 3815 and a scanner from a shop, and a scan from advance as well.
But i dont think it could be a strap in the battery as theres no other problems, she cranks fine, voltages are all right where they should be and everything. just randomly shuts down. (or could it be?)
CMCKENNA, where you at? I got time to investigate today.
im not sure if this could be the problem. is it possible that wires are touching, causing something to ground out? but its barly touching becuase you can start it again. and maybe (while truck is running) since it has more voltage going through, its causing the short. and your able to start it again, because all the power is not at the wire anymore.
Not sure if you understood this, but it seems logical
The power is at a constant and is not supposed to drop. So, no matter if the vehicle is on or not, the voltage is always the same at the PCM, and through all the feeds as the battery is the source for the PCM side.
If it were a short, it would pop a fuse as well as arc. The amount of voltage is low but, some of the current is very high. One would see and smell that type of short immediately.
On the low voltage components such as sensors, it is quite possible to have a damaged harness at which point it would ground out thus tripping the PCM to kill the system. That's a mere 5 volts so, one would not see, smell nor hear it arcing.
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96 Dodge Ram 1500 4WD, Hughes Fi Airgap, Custom Al -6AN billet fuel rails, Bosch FIs, JBA headers/ JBA perf. exhaust, F&B TB, Summit- -6AN fuel supply lines, Magnaflow hi flow CAT, Pulstar plugs, Moroso Ultra 40s, SCT, MSD coilpack, Volant CAI / Kenwood Excelon XVT 819 DVD, Alpine PDX 4150, Kenwood KAC-X10D, Boston Acoustics, single 10.
Well the problem is When i thought i fixed it by cleaning the crank sensor, it ran fine without shutting off for almost a month. so I dont know when/if it will shut off, sometimes ill be runnin 55 down the hwy, 75 on the interstate, 35 on a side street, or even stopped at a traffic light. I just dont know, when/if it'll shut off. and from my expierence there has been no correlation between each time its shut off. and no codes present or stored as check with my 3815 and a scanner from a shop, and a scan from advance as well.
But i dont think it could be a strap in the battery as theres no other problems, she cranks fine, voltages are all right where they should be and everything. just randomly shuts down. (or could it be?)
CMCKENNA, where you at? I got time to investigate today.
95Ram what wires are you refering to?
Oh, I am out and about except just a quick peak to see where you were at. I am out in the shop myself making wire looms. After that, I am taking it out for a test run. I just finished tweaking the fuel delivery system into the final configuration. I just trashed my MSD ignition wires as they were nothing but Chinese junk and were showing high resistance and open circuit conditions thus causing misfires.
Anyway, I am out trying to get my own vehicle out of the garage and out onto the pavement today.
The thing is, you had mentioned that after cleaning the CKPS, the truck ran fine for about a month. I would get into that harness and start measuring the voltage while it's running.
- Get at that harness in the rear for the CKPS. It's on the right of the dizzy in most cases unless it has been relo-d behind the intake for easier access.
- Using the schematics, backprobe that damn connector for the CKPS and see what that the voltage is doing while she's running. Monitor it closely. I will dig through the schematics on my end (if I have time) and find what the min value is. I believe it is 4VDC. I think that the spec was stated as 5
VDC -1VDC. It shouldn't go over more than 5 due to the design but, it will fall below.
Let's see what we got.
This whole shutdown is now clear to me. It happens at random, at any time, any speed, any condition thus, we have a sporadic event.
In the event that happens, you lose power to everything in the vehicle. Now, the thing is, in NORMAL failure mode, the PCM is supposed to be kept alive thus allowing it to store a DTC.
The thing that is out of the norm is the fact that when this happens, ALL power is cut TO the PCM thus causing the CCD bus error message as well as not displaying any codes.
What year is your truck?
I need to get out the damn schematic in order to refresh my memory whether or not ALL power is cut at the ASD or just power to the engine management systems.
Once I find the power feed / source for the PCM, I think we will have a better idea where to start looking. In the meantime, please check your CKPS.
I don't have time to write it out step by step but, please refer to the Haynes Manual as I "think" (not sure) that they 'may' have a diagnostic procedure that explains it out.
I am off to the shop.
Chris McKenna
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96 Dodge Ram 1500 4WD, Hughes Fi Airgap, Custom Al -6AN billet fuel rails, Bosch FIs, JBA headers/ JBA perf. exhaust, F&B TB, Summit- -6AN fuel supply lines, Magnaflow hi flow CAT, Pulstar plugs, Moroso Ultra 40s, SCT, MSD coilpack, Volant CAI / Kenwood Excelon XVT 819 DVD, Alpine PDX 4150, Kenwood KAC-X10D, Boston Acoustics, single 10.
Last edited by cmckenna; 11-08-2009 at 07:14 PM.
Reason: Typos
