In the last week I'd been getting a bizarre list of error codes from time to time when first cranking the truck. I'd get "battery disconnected' or "low voltage" for the ECM, TCM, FCM, SKIM and vehicle VIN configuration errors and it would put the transmission in fail-safe mode. I started by cleaning all the battery connections and grounds but that didn't help. After a few instances, I realized it was only happening when I cranked the truck, but never while going down the road or hitting a bump. I picked up a replacement ignition multi-function switch yesterday and installed it this morning. I went shopping and running errands afterward and probably turned it off and on about 20 times today with no more codes. Yay!

The only odd thing I ran into was the column tilt release lever. I have an electronic FSM for 2005 and a paper FSM for a 2007 and they both show the tilt release lever with a cable that "pulls" on the latch and you rotate the lever to make it work. My 2006 had a bent L-shaped rod that was connected to a mechanism that "pushed" on the latch to keep it locked until you pulled back on the lever. It was only an issue because it had to be removed to access the screws for the ignition switch. I removed the screws and let it hang while I worked on pulling the key cylinder and it fell to the floor in the process. The problem is that I didn't really notice where it was connected to the latch when I removed the mounting screws. After staring at it for a few minutes, I came here to look for info (unsuccessfully) and to You-Tube (also unsuccessful) I finally got under there with my flashlight and a mirror and figured it out. It just seemed odd that the 2006 was different from the 2005 and the 2007.

 

I have noticed that some of the diagrams in the 2005 manual don't necessarily match exactly what I'm looking at on the truck. The reference-numbers pointing to specific parts in the diagrams seem to be particularly notorious for not matching the corresponding reference-numbers of the parts in the procedure descriptions.

Regarding the replacement of the ignition switch, on these trucks if the battery is nearing its end-of-life (even if it's still able to crank the engine), weird electrical gremlins and codes tend to show their evil faces. If it starts to do weird things again, I would consider replacing the battery...even if it "tests ok".

 

My battery is only 6 months old, but I did start with the battery connectors and grounds, checking alternator output and resting battery voltage. I even thought about a loose plate in the battery, but I drive over 2 railroad tracks every day on the way to work and back and it never hiccuped. I had 2 "no-start" episodes and several startups with pages of error codes on my Blue Driver OBD reader for loss of voltage or communications, along with lots of "implausible...."

 

This has turned into a real snipe hunt and I haven't found the root cause yet. It only happens when I crank the truck up, but it has happened on both cold starts and hot re-starts.
-The battery is 6 months old, sits at 12.75 volts and doesn't drop below 10.5v when cranking. The alternator puts out 14.2 right after cranking and settles to 13.7V after a minute.
-I started by installing marine grade post clamps, cleaning the battery cable eyes, and cleaning the chassis ground, engine ground, and PCM chassis ground.
-I pulled the Front Control Module and cleaned the connection to the fuse box and the two wiring harness connectors on bottom
-I pulled and cleaned the connectors to the transmission and all four connectors to the ECU/TCM
-After considering that the problem comes only at start, I replaced the ignition switch.

I'm starting to think the Front Control Module may be failing. I believe it's the gateway for the other modules. I found one with the exact same part number but I haven't bought it yet.

I don't get every fault code every time but this is a list of modules that have set fault codes;
Engine Control Module, Front Control Module, Occupant Restraint Controller, ABS Controller, Powertrain Control Module, Transmission Control Module, SKIM wireless control module.

 

Do you have an aftermarket stereo?

 

No aftermarket stereo, no extra electronic equipment.

 

battery . if its only showiing 12.5 its due, new or not check into its warranty mine shows like 13.6 and its a year and a half old drops to 11.3 when cranking

 

I just checked mine, which is about 6 months old. 12.9 after sitting overnight, and hadn't been run for about 24 hours.

 

I picked up a new battery today and will report back in a few days.

 

That didn't take long. Got a new battery yesterday but the problem came back today. I guess I'm in the market for a new Front Control Module.