Puzzled Truck Won't Start

[Kevin_D]

Don't get distracted by the brake pedal thing if the voltage is THAT low.

The brake booster gets its vacuum from an electric vacuum pump on the front of the motor. So with low voltage, the pump won’t run, you get no vacuum, so no power assist on the brakes.

Kevin

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[ShadowsPapa]

The brake booster gets its vacuum from an electric vacuum pump on the front of the motor. So with low voltage, the pump won’t run, you get no vacuum, so no power assist on the brakes.

Kevin

OK, I didn't maybe convey the thought correctly?

I meant this - some were saying it wouldn't start because the brake pedal couldn't be pressed.
No. Not in this case. It's voltage that's the no start thing.

Don't get tangled up in hard brake pedal being the reason - press harder all you want but with 11 volts and lower, don't expect it to start. The hard brake pedal is a symptom, not a cause.
Some were saying it wasn't starting due to hard brake pedal.
I'm saying that's an effect, not cause.
It's not starting because there's no battery.
No one should even be trying to start a vehicle with battery voltage at 11 or less.
Charge it.
If you do get it started at 11 volts or less and drive away with it, and the engine dies, you are screwed.

There was a lot of guessing going on - and people were missing the elephant in the room - voltage, no battery power. Depending on the tech docs you read, when battery voltage is too low the IBS sends a signal and the vehicle is told not to wake up certain things............

 

[Kevin_D]

The hard brake pedal is a symptom, not a cause.

Exactly.
I was presenting a reason why the brake pedal would be stiff with a dead battery.

Kevin

 

[ShadowsPapa]

Exactly.
I was presenting a reason why the brake pedal would be stiff with a dead battery.

Kevin

Gotcha, same page.

 

[jebiruph]

I'll give it a look as a back up to their diagnostics but basically yep the ESS went down and then it took the main battery down as well.

Both going down together usually means they are still connected in parallel and the ESS fuse is good.

 

[ShadowsPapa]

I'll give it a look as a back up to their diagnostics but basically yep the ESS went down and then it took the main battery down as well.

That's exactly what happened with my wife's 2018 about a month before she traded it. The aux battery was bad, ESS stopped working, then a couple of weeks later after the beast sat for a couple of days, it wouldn't start. It finally got to a point you couldn't charge the batteries. Dealer said the aux died and took the main battery with it, sucking the power out of it as it sat, ruining it, whatever.

 

[ShadowsPapa]

It's very easy to charge either, or both batteries, independent of each other. No need for jumpers, splitting things apart, messing with the PCR or anything like that. LOAD testing like a dealership does is a different animal, but for home charging, it's easy as long as you don't try to blast a charge in at super-high current.......

Loosen the clamp that holds the IBS onto the main (crank) battery negative terminal.
Use something to hold the negative cable assembly you removed up off the crank battery negative terminal. I had a small block of wood handy so used that between the negative cable assembly (with IBS still connected) away from the crank battery negative post.
You can now simply connect to the crank (main) battery positive post area and the main battery negative post with a charger.
To charge the ESS or aux battery, you would connect to the same positive cable group at the main battery but instead of connecting the negative of the charger to the main battery negative post, you'd clamp onto the cables that are bolted to the IBS because one of those cables goes down to the aux battery.
You will know if the high current fuse N3 is blown because your charger won't see a battery connected. IF it's blown you want to resolve that issue anyway, so fix it first, and then charge the aux battery by clipping the charger to the positive cables at the main battery and the negative cables you lifted off the main battery negative post.

I charged both main and aux batteries at the same time, but independently, by using two different chargers.
The positive clips of both chargers went to the red cable connection at the main battery.
The negative clip of one charger went to the negative terminal on the main battery.
The negative clip of the other charger went to the negative cable group I lifted off the main battery terminal along with the IBS.
It works just fine as long as high current fuse N3 is not blown, but again, if that's blown you want to fix it anyway, this is one way to find out if it's blown.
No jumpers, no extra fuses, no removing anything except lifting the IBS, with both black cables still connected to it, off the main negative post. It's that simple.
If you unbolt the IBS from the black cable assembly, then you are resetting the IBS at the same time as it relies on being connected in a circuit to learn and monitor. Taking it off both the battery negative and off those black cables shuts it down and clears the IBS memory.

 

[BAT]

That's exactly what happened with my wife's 2018 about a month before she traded it. The aux battery was bad, ESS stopped working, then a couple of weeks later after the beast sat for a couple of days, it wouldn't start. It finally got to a point you couldn't charge the batteries. Dealer said the aux died and took the main battery with it, sucking the power out of it as it sat, ruining it, whatever.

I was lucky I was able to get a charge back into my main battery. But what got me was that the truck was running fine and had not been sitting up. I had just driven the thing some hours before but so far its running fine again and the battery is holding well.

 

[ShadowsPapa]

I was lucky I was able to get a charge back into my main battery. But what got me was that the truck was running fine and had not been sitting up. I had just driven the thing some hours before but so far its running fine again and the battery is holding well.

I'm glad it's working again now. On the surface of it, this is really strange and has me interested. I hope you don't post again later with further problems but am interested in seeing how things hold up, or if they don't, the continuing story, I guess. Maybe this thread will die because your truck will behave perfectly for years to come.

 

[BAT]

I'm glad it's working again now. On the surface of it, this is really strange and has me interested. I hope you don't post again later with further problems but am interested in seeing how things hold up, or if they don't, the continuing story, I guess. Maybe this thread will die because your truck will behave perfectly for years to come.

Yes that is the outcome I am hoping for it will continue with no issues. I haven't had much since I bought it. The steering box which they changed and have had no further issues and just this. Maybe I will eventually move to the Genesis dual battery and get away from this current deal they have. The lucky thing was I was about to leave for a kayak trip that would have had my truck in the middle of nowhere should that battery had died on me then.

 

[BAT]

Oh dang I forgot I am watching as the Auto Start/Stop function is not working now since they changed the new battery. I noticed yesterday when I forgot to turn it off and I have not remarried my Tazer yet. It did not shut down any of the times I stopped for prolonged periods

 

[ShadowsPapa]

Oh dang I forgot I am watching as the Auto Start/Stop function is not working now since they changed the new battery. I noticed yesterday when I forgot to turn it off and I have not remarried my Tazer yet. It did not shut down any of the times I stopped for prolonged periods

IBS relearn? Assuming they had it disconnected from the main battery and the negative cables taken off the IBS?

Oddly, my ESS IS working even though it's NOT supposed to when the IBS is in learn mode! That tells me the IBS is really messed up because every piece of tech info I have says that until it learns what the batteries are like and are capable of, ESS won't work, and it takes 4 or 5 start cycles with at least 8 hours between them for it to learn. My ESS was working as soon as I put the IBS back in place and that's just plain wrong.

 

[BAT]

IBS relearn? Assuming they had it disconnected from the main battery and the negative cables taken off the IBS?

Oddly, my ESS IS working even though it's NOT supposed to when the IBS is in learn mode! That tells me the IBS is really messed up because every piece of tech info I have says that until it learns what the batteries are like and are capable of, ESS won't work, and it takes 4 or 5 start cycles with at least 8 hours between them for it to learn. My ESS was working as soon as I put the IBS back in place and that's just plain wrong.

Well I suppose it has relearned as you mentioned since today the auto start/stop started working again but I haven't reinstalled my tazer yet. I also noticed oddly that my license plate lights are crazy bright now compared to before it went in. There is no mention of a change of the lights on the work order but man when I go into reverse now at night they are so bright I cannot really see anything. Gonna have to check on that

 

[Mr._Bill]

Well I suppose it has relearned as you mentioned since today the auto start/stop started working again but I haven't reinstalled my tazer yet. I also noticed oddly that my license plate lights are crazy bright now compared to before it went in. There is no mention of a change of the lights on the work order but man when I go into reverse now at night they are so bright I cannot really see anything. Gonna have to check on that

That's one of the Tazer features. It turns off the license plate lights when in Reverse.

 

[BAT]

That's one of the Tazer features. It turns off the license plate lights when in Reverse.

Ah yep. Its been raining a good bit today so didn't get a chance to get it married back up again hopefully tomorrow after work

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