8.4AN GPS has wrong time

[Alan Reagan]

I just went through this including the update from the dealer. My gps sync time was 4 hours and 15 minutes off and it occurred a week after the update. I disconnected the batteries for 30 minutes and no change. Since I’m an electronic engineer, I started to look at this problem a little closer. I pulled up the EVIC screen showing the battery voltage and it was only showing 12 volts with the truck running. With a VOM, the voltage was 14.2. I shut down the truck and measured the resistance of the frame ground points back to the battery. In the left side, under the hood, the resistance was 18 and 14 ohms. The ground lines are a max of two feet long. I removed the bolts and cleaned the ground connections and the resistance went to .2 ohms on both points. I restarted the truck, synced to GPS time and just left the display up. After about 30 minutes, the time corrected itself and I’ve had no more problem with it. In conjunction with this, the GPS was showing my location to be about 5 miles from my actual location. Since clearing up the ground, that problem has corrected itself as well. The dealer said if this happened after the unconnected update, I would have to have a new radio. Apparently, that’s not the case.

I checked the batteries first because every time I’ve had a radio problem in one of these trucks, it was an indication that the batteries were going bad. The radios in the 4th gen trucks trucks seem to be very sensitive to voltage fluctuations and low voltage conditions. In my case, it was just a bad ground.

 

[Wiredawg]

I just went through this including the update from the dealer. My gps sync time was 4 hours and 15 minutes off and it occurred a week after the update. I disconnected the batteries for 30 minutes and no change. Since I’m an electronic engineer, I started to look at this problem a little closer. I pulled up the EVIC screen showing the battery voltage and it was only showing 12 volts with the truck running. With a VOM, the voltage was 14.2. I shut down the truck and measured the resistance of the frame ground points back to the battery. In the left side, under the hood, the resistance was 18 and 14 ohms. The ground lines are a max of two feet long. I removed the bolts and cleaned the ground connections and the resistance went to .2 ohms on both points. I restarted the truck, synced to GPS time and just left the display up. After about 30 minutes, the time corrected itself and I’ve had no more problem with it. In conjunction with this, the GPS was showing my location to be about 5 miles from my actual location. Since clearing up the ground, that problem has corrected itself as well. The dealer said if this happened after the unconnected update, I would have to have a new radio. Apparently, that’s not the case.

I checked the batteries first because every time I’ve had a radio problem in one of these trucks, it was an indication that the batteries were going bad. The radios in the 4th gen trucks trucks seem to be very sensitive to voltage fluctuations and low voltage conditions. In my case, it was just a bad ground.

Great Post! I'm a retired IT Project Manager and many problems on command and control (C2) systems and automated communications systems can be traced to bad and dirty grounds. I'm getting ready to install a continuous duty air compressor and while doing that, going to inspect and perform preventative maintenance; remove ground, shiney it up, apply dielectric grease to the metal, tighten back up, clean top with solvent, then apply paint to seal it.

Although I haven't been very successful convincing folks to do this with connections associated with the Integrated Brake Controller as I suspect grounding/ connector issues.

Thanks again for sharing! Cheers, Ron

 

[Alan Reagan]

Wiredawg, Thanks for your service. I retired after 28 years Coast Guard and Navy.

Also, thanks for bringing up the di-electric grease. I used it on the grounds this time and anytime I take a connector apart, I put some on the pins. I was really surprised at the high resistance to ground. Also, since I did this, my cruise control comes on when I press the button instead of having to do the set/cancel combo press to make it turn on. My drivers window switch was intermittent when the truck was first started. That problem is gone. In every problem, the switches were fine. The bad ground was causing intermittent electronic problems that have now gone away.

 

[Alan Reagan]

Well, my truck was back at the dealer for the gooseneck ball recall and the tech did the latest GPS update. I started on a trip the next morning and it took about 40 miles to figure out where I was. When I reached my destination, I downloaded the latest update and installed it per the instructions. Since the, it has worked fine. It did take a while for the time to sync with GPS but all has been fine since I did the update. The tech must have left out the door open and close steps at the end which completes the update.