I am requesting opinions and feedback about an electrical accident that occurred while working on my truck. Last week I was attempting to Remove the Batteries from my 2006 Dodge 3500 Cummings Turbo Diesel Truck. This all started when I noticed the Check Engine Light came on and stayed on when I started the truck. I suspected that the batteries were going bad since in the previous starts the truck was sluggish when starting up. I am the original owner of the truck and at the time it was still running on the original batteries that came from the factory (I live in Las Vegas and I have been told that 6 years must be a record). The truck is not a daily driver and it is used primarily for camping and fishing trips and has about 42K miles.

I started by removing the negative cable on the drivers side battery and I moved it out of the way. Then I removed the positive cable but it slipped out of my hand and the cable clamp hit the metal shielding of the heater hose which was less than 4 inches away. A spark resulted from the impact which lasted for about 1 second. I reconnected the cables and tried to start the truck but now I got a Check Engine Light that was Blinking and a Red Blinking Light located on the lower right of the Instrument Panel. Also I heard a clicking noise coming from the engine compartment. I opened the fuse box in the engine compartment hoping that one or more of the 20, 30 or 40 AMP fuses were blown and any of the others. But they were all fine.

I called a dealer that I trust and he told me to check the fusiable link wire on the passenger side battery to see if it self destructed. It is designed to protect the Truck in the event of a serious short like what happened to me. But this wire seems to be intact. Then I went to the dealer where I bought the truck from and spoke to a Service Technician. He told me that they are getting a lot of the same issues with auction companies where the workers are having the same accidents as I am. He said that the ECM is probably blown and I will need a new one after I told him how the Instrument Lights are acting. Also, he said that I cannot install the new ECM myself since THEY need it to program it themselves with my truck at their shop. This is obviously a huge cost (New ECM from the dealer is over $2200). Later that day I tried starting the truck again and it turned over and this gave me hope but it did not fire up.

The next day I spoke to a mechanic at another dealer and I told him the story. He said that I was very helpful with my diagnosis of the problem especially when it came to the Red Blinking Light. He said that it was very strange that the truck did turn over but did not fire up. He said that the keys have a microprocessor that communicates with the ECM. It is possible that I will have to reprogram the keys to communicate with the ECM. The worse case is that I fried the ECM. The best plan is to reboot the ECM. I am to disconnect the battery cables and wait 10 minutes. Then hook them up and try to start the truck. Note all events that happen. Also it might be good to test the backup key that came with the truck.
Well after 10 minutes I reconnected the battery cables and prayed that rebooting the ECM would solve my problem. It started right up immediately and I was ecstatic. I called the mechanic back to verity the following questions and concerns:

1. The Check Engine Light was on and he agrees with me that it is because it was sensing a low voltage condition for the battery. The light will go out after 3 engine cycles.

2. The problem in my case he feels was that ECM needed to be rebooted since the keys were not communicating with the truck. If there is a communication problem with the Key, ECM, wire harness, instrument cluster etc. the Red Blinking Light is the warning. When I sparked the truck I disrupted the communication link and this is why the Truck did not start. Another important item was the fact that the truck did turn over but did not fire up.

When I brought the old batteries to the store to get the new ones I had the old batteries tested. The driver side battery was still able to produce 11.5 volts under load while the passenger side battery was only able to produce less than 1 Volt under load. When I zapped the truck it was the power from the passenger side battery that delivered the electricity. That is why the spark was not so dramatic in intensity. This could have saved the ECM.

I installed new batteries in the truck and I noticed after it started the check engine light came on. This was a concern and I thought it was connected to the fact that the Truck sensed that the batteries were missing when I changed the old batteries for the new ones. I went for a drive to charge the new batteries since they were probably sitting on the shelf for some time before I bought them. Also I thought that the ECM will need to start “Learning” all over again. I drove about 100 miles roundtrip to Arizona. The temperature at Las Vegas was 111 degrees and when I got to AZ it was 115. I felt this would be a good torture test for the ECM. When I started the Truck before I left home the MPG displayed was 14.9. I started counting the number of sessions that the Truck was started. The first Session was right after I started the truck after I installed the new batteries which lasted less than a minute. When I got to the turn off road in Arizona I turned off the engine again and started it up and that was session no 2. When I got home the MPG display had risen to 16.9 MPG. Then I started it up again and that was Session no.3 and the Check Engine light has disappeared and it has not come on since.

I still was not totally convinced that the ECM was fully functioning so I contacted a company that repairs and offers Refirb ECMs and they told me that I could still have problems with it in the future. It could blow capacitors etc. I was told to drive it some more and see what the ECM does. In addition I was due for my annual smog check which involves a Dyno test here in Nevada. This will be a great test for the ECM since the smog computer and Dyno will really put the ECM though its paces. Before the smog test I drove 50 miles to get the Cat good and hot. I noticed that the MPG had now risen to 17.7 MPG. The truck passed with flying colors like a new truck. The smoke from the exhaust was a little noticeable under load when the tech was driving. It looked like the last smog tests that I have done in the past few years. I told the tech what happened and he said that he feels that the truck is fine.

Last questions and doubts:

I. Did I loose the old Upgraded Software that was flashed by the Factory when I picked up the truck in May 2006 ?

2. Will more drives will help the ECM learn more ?

3. Finally, the big question is the ECM is fine and was I DAM lucky ?