How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Robert Your Own Question
Robert
Robert, ASE Certified Technician
Category: UK Car
Satisfied Customers: 4159
Experience:  ASE Certifications in Engine Repair, Manual Drivetrain and Axles, Suspension and Steering, and Heating and A/C.
49095596
Type Your UK Car Question Here...
Robert is online now
A new question is answered every 9 seconds

2005 Ram w/ 5.9 TD won't start, can't connect to StarSCAN

Customer Question

2005 Ram w/ 5.9 TD won't start, can't connect to StarSCAN and the MIC displays "no bus" I've put the PCM in a separate truck and the StarSCAN connects reporting "vehicle unfamiliar" but it does see it. I've tested the MIC and all gauges/lamps past the test, I've switched MIC's with another vehicle and it too passes all tests. I have "C" codes that relate to head lamps, (which I have no control of), wiper switch (which randomly comes on when connecting the batteries but I can't get to function from the lever), and/or the turn signals/hazard lights, the PRND12 for the transmission lever are all in "squares" verses just "P". I've inspected all fuses/relays, switched out the module on the PDC, disassembled the PDC and inspected for breaks/wear, inspected the ABS module and connections, checked for good ground from the Data Link Connector in pins 4/5. I haven't been able to locate a wiring diagram for the DLC, PCM, or the MIC so I can test good grounds in the wiring harness.
Suggestions and/or any information will be greatly appreciated.
Thanks,
Anthony
Submitted: 10 months ago.
Category: UK Car
Expert:  Robert replied 10 months ago.

Hello, welcome and thanks for asking your question. My name is*****'m a Certified Auto Technician with 28+ years experience. I will do my best to assist you. please keep in mind that I may need to ask questions of you before I can answer. When you reply please feel free to add as much detailed information as possible pertaining to your concern.

Can you post the last 8 digits of the VIN so that I can do some research on this concern for you?

When you swapped the PCM to another truck, where was the PCM that you removed from your vehicle located? Right side firewall??

Keep me posted...

Thank you,

Robert

Customer: replied 10 months ago.
Last eight are 5G812810, the PCM was attached to the left side (driver side) of the cummings diesel engine.
Thanks
Customer: replied 10 months ago.
on the truck I have the following, ECM FLASH/UPDATE P/N 25325333AH. Under this it has CHNG AUTH 21-006-07, DEALER CODE 59350 and DATE 9-25-07
Customer: replied 10 months ago.
At the shop currently and the PCM has the following... please see photo
Expert:  Robert replied 10 months ago.

Ok, Good, I mainly wanted to make sure we are on the same page with the PCM. Some trucks have a separate module mounted to the right side firewall and this one is for transmission functions. On yours since all the prndl indicator lamps are illuminated, I suspect that the problem could be with the transmission wiring. Check the transmission electrical connector and wiring harness for problems. The wires can get damaged close to the connector and short out to each other. Check this connector and harness carefully. I suspect a short on the 5 volt sensor supply circuit to be shorted bringing down the PCM and PCI BUS.

Check these areas and post back any results. Also try communicating with the PCM with the transmission harness disconnected..

Keep me posted...

Thank you,

Robert

Customer: replied 10 months ago.
Sounds good thanks,
I'm taking a long weekend so you won't hear from me until Tuesday night.
Thanks again,
Anthony
Expert:  Robert replied 10 months ago.

I'll be here whenever you're ready...

Thank you,

Robert

Customer: replied 10 months ago.
Alright, disconnecting the tranny made no difference, no "square" indicated around any of the letters, no engine start (or even starter engaging) when turning the key. The tranny plug took a few minutes without a wiring diagram to give you aqerate info but looking at the plug with the "tab" at the top and assuming the second pin from the left is ground (with my volt meter this was my conclusion), with the key on the 1-2 pin has 7 volts, 2-4 is 5, 2-5 is 5 and 2-6 is 6.6. With the key off 1-2 is 1.3 volts and the rest 1.4 volts. Pin 3 has no wire.
I even removed the #59 relay for the tranny in the PDC and got the same response as unplugging the tranny wiring harness.
I noticed on the MIC when the tranny is put into gear it doesn't indicate which gear "square" until I try to turn the key off then it illuminates the "square" until I put it in Park and finish removing the key
Expert:  Robert replied 10 months ago.

Here is the connector so you can see what each wire goes to...

Click Here

Keep me posted...

Thank you,

Robert

Customer: replied 10 months ago.
wow, that doesn't look anything like what I pinned out today... this is located on the transmission? So far all the wiring diagrams I've located (8w-whatever) hasn't matched to the wiring harness in the vehicle.
Expert:  Robert replied 10 months ago.

Hello,

Here is a pic showing the left side of the transmission. I am thinking that you were testing the Transmission Range Sensor connector. The one I need you to check is the transmisison solenoid connector. Check this connector and keep me posted on what you find...

Thank you,

Robert

Customer: replied 10 months ago.
Alright, pinned out and looking at your image 2-3 and 8-3 had 5 volts, no volts anywhere with the key off
Expert:  Robert replied 10 months ago.

Did you try to start the engine or communicate with the ECM when you had the transmission connector unplugged? IF not, try this and post back the results.

Thank you,

Robert

Customer: replied 10 months ago.
the headlights remained on, the wipers operate on their own, I still have "no bus" on the MIC, still have the air bag light, still have the ABS light, still no "square" around any of the gears for the transmission and the starter still won't engage to attempt starting/turning over the engine.
Expert:  Robert replied 10 months ago.

Ok, Next step is to check the 5 volt supply circuits for shorting. Start by disconnecting any sensor on the engine that is supplied 5 volts from the ECM. Check for 5 volts at the 5 volt supply circuit. IF 5 volts is present, check to see if the No Bus is still active. IF no longer active, that sensor is internally shorted. If 5 volts is not prresent, continue disconnecting sensors to see if the 5 volts return, If no 5 volts still. we need to start checking the wiring closer to the ECM.
For now Here is the ECM pinouts so you can back probe all the 5 volt supply circuits. IF any of these don't have 5 volts, clip that wire about 4 inches from the connector and recheck the voltage at the ECM side of the wire. IF 5 volts is now present, there is a short somewhere on that wire. you will need to see what that 5 volts supplies to see if there is a sensor that was overlooked. IF none overlooked, let me know.

HERE is the connector pin chart for the ECM --- Let me know if you need wiring diagrams and for which circuits....

Keep me posted and let me know if you have any additional questions...

Thank you,

Robert

Customer: replied 10 months ago.
lol,
Robert, you took my MIC/ACM problem as well. Aren't you the lucky one...
no need to repeat myself regarding the weekend and the car how I attended,
I did make a very interesting discovery last week. While troubleshooting my PCM I noticed that when I would turn the ignition on the transmission indicator would "hint" at "R" right before the cluster would light up with "gauges" so I adjusted the key to indicate this "R" then I would slip it into "N" and turn the key, the truck started!!!! Only ran for about 3-5 seconds and then would die, unfortunately this could be for at least two reasons, 1) "no bus" would illuminate on the dash at this time, 2) this PCM isn't the correct PCM for this vehicle (VIN conflict). I was able to duplicate this a dozen times, my newest problem... a coworker was helping and adjusted the shift cable under the dash so the indicator "hints" to "P" now when you turn the key but it won't start as I did before, now it turns and turns but sounds like it isn't getting any fuel, I'm assuming because of the "no fuel" indicated on the gauge. Since the adjustment of the cable now the shifter is locked in position until the PCM has power so slipping it to "N" isn't possible. So my question here is why would the truck start (even for 3 seconds) in "N" but acts like it is getting "no fuel" in "P"?
Also, I've noticed now the wipers no longer randomly come on when I connect the battery.
Suggestions? I'm still going through the PCM pins, had a different vehicle today so I didn't get to look at it.
After these two posts I really hope you enjoyed your weekend.
Expert:  Robert replied 10 months ago.

You mentioned the PCM is not the correct one from this vehicle. IF it has a different VIN, that would count for the start for 3 seconds AND the crank no start condition. I suspect that if you now switch it to neutral that it will just crank and not start at all. This could be due to the NO BUS and also that the PCM has the wrong VIN. The PCM and the Immobilizer module are "Married" together and if you switch either, the vehicle WILL crank and start for 3 seconds, then after a few tries will not start at all. This will also make the "Red Dot" lamp either illuminated or flashing...

At this time, we need to get the modules to communicate with each other. The best way would be to use a FACTORY scanner to see which modules are actually offline. Once we determine what modules are offline we can start to determine where to check for problems...

Keep me posted...

Thank you,

Robert

Expert:  Robert replied 10 months ago.

Hello,

I just wanted to check in with you to see if you need more help with your concern. A non rated question normally times out within 7 days, so I wanted to stay in contact with you to see if the problem has been solved.

If I have helped you resolve your concern and you have already rated my response, I want to say "Thanks, ***** ***** you know you can still follow up on this concern if needed. Also to let you know you can bookmark >>> My Profile Page <<< in case you have another automotive question in the future. Make sure to begin your question with "Robert R" so I will be able to easily find it

If we are still working on your concern, please post a reply so we can continue.

If you are happy with my answer and have not rated my response, please do so asap to complete the transaction. It is greatly appreciated as I recieve no compensation until you do so...

If you're not satisfied with my answer, BEFORE rating, please post a reply with a short explanation as to why. I may have a better explanation for you... It also helps me to refine my answers to help future customers more thoroughly and efficiently.