Bronco lost power on an obstacle

[Eric L]

Ok...this is a longshot. I was rockcrawling in Vernal 2 weeks ago, locked up, on a steep obstacle and my bronco had no power. I had it floored and nothing. Had to winch up. No check engine light and drove home under power just fine. The only thing I changed from the last time out was I had an ARB airlocker installed in the Dana 60 rear end. Not sure if there is any causation there or not. Someone said maybe cam phasers? The dealership couldn't figure it out. They said one of my portals was locked up which wasn't true. Any ideas?

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[Ducati1098]

I know you said no check engine light, but did the dealer check for, or note any historical codes?

Doesn’t sound like phasers at all, more like potentially a throttle control issue if it was still running. Although that would typically set a check engine light right away.

 

[PWillette]

Ok...this is a longshot. I was rockcrawling in Vernal 2 weeks ago, locked up, on a steep obstacle and my bronco had no power. I had it floored and nothing. Had to winch up. No check engine light and drove home under power just fine. The only thing I changed from the last time out was I had an ARB airlocker installed in the Dana 60 rear end. Not sure if there is any causation there or not. Someone said maybe cam phasers? The dealership couldn't figure it out. They said one of my portals was locked up which wasn't true. Any ideas?

@SierraBronco may have input on this.

 

[SierraBronco]

@SierraBronco may have input on this.

Based on the description and no visible codes, it wasn’t in limp mode. Otherwise you’d need to do a hard reset. I’m putting my money on the torque limit being reached. My understanding is that it’s in the computer settings to prevent us from breaking stuff. This can be changed with a tune

RPM increased but only a little and wouldn’t go any higher?

 

[Snacktime]

Did you just winch up? No trouble shooting? Turn on and off?

Need more information! I have a theory that if the Abs detects an abnormal signal it cuts power. @NORCALGXP had issues with an ABS sensor it completely cut power. When I blew my front diff and went crashing backwards I had no brakes or power(2 footing it with both to the floor). Been a few times when similar events have happened offroad with other wheelers. I don't think its linked to loss of signal but more of a signal indicates an event that triggers. @NORCALGXP one sensor was reading massive signal voltage higher than all the others, cleaned the sensor and back to normal.

 

[Eric L]

I know you said no check engine light, but did the dealer check for, or note any historical codes?

Doesn’t sound like phasers at all, more like potentially a throttle control issue if it was still running. Although that would typically set a check engine light right away.

They didn't say if there were any historical codes.

Based on the description and no visible codes, it wasn’t in limp mode. Otherwise you’d need to do a hard reset. I’m putting my money on the torque limit being reached. My understanding is that it’s in the computer settings to prevent us from breaking stuff. This can be changed with a tune

RPM increased but only a little and wouldn’t go any higher?

That would be really weird because I've wheeled that thing for 5 years breaking my share of parts. It was at about 1000 RPM and wouldn't go higher. But it drove off the trail and back to SLC just fine. It's so bizarre

 

[NORCALGXP]

Did you just winch up? No trouble shooting? Turn on and off?

Need more information! I have a theory that if the Abs detects an abnormal signal it cuts power. @NORCALGXP had issues with an ABS sensor it completely cut power. When I blew my front diff and went crashing backwards I had no brakes or power(2 footing it with both to the floor). Been a few times when similar events have happened offroad with other wheelers. I don't think its linked to loss of signal but more of a signal indicates an event that triggers. @NORCALGXP one sensor was reading massive signal voltage higher than all the others, cleaned the sensor and back to normal.

@SierraBronco @Snacktime In transient back to the US. Have lots of thoughts on this subject. Has happened a number of times on difficult obstacles.

 

[SierraBronco]

They didn't say if there were any historical codes.

That would be really weird because I've wheeled that thing for 5 years breaking my share of parts. It was at about 1000 RPM and wouldn't go higher. But it drove off the trail and back to SLC just fine. It's so bizarre

Yeah, I absolutely could be wrong, but it does seem like several variables need to be met before it kicks in. Kinda like how the anti-hop doesn’t step in and kill your engine without being at a certain angle upward. Once we disabled that the Bronco has never again died while trying to climb something whereas other rigs without that disabled and similar set ups did have the engine die. On the third obstacle of the pickle in Moab both. @NORCALGXP and wifey must have met the conditions necessary to limit back the Torque. As both got into a situation where the Bronco would not go over a certain RPM. He got through it by backing up and using copious amounts of throttles, we got through it by picking a different line.

 

[CitrusBronco]

Interested in the answer.
I’ve lost power a few times, always in mud holes going in with 2wd and getting stuck.
I assume power was reduced either by traction control or some sort of engine management directly due to higher rpm.
Each times I put it into 4wd and full power was restored.
Is this related to what op experienced, not sure but sounds similar.

 

[zuke]

I've had a similar experience, in my case I believe the trigger was getting the transfer case to overheat, at first it just limited rpm and I kept trying to get it to climb and it finally gave me a. Cryptic codes about the 4wd system being overheated, and completely disabled 4wd with a service now message. Got drug the rest of the way up the hill by an LJ, . Shut it off and let it sit until the rest of the group got up the hill, about 30 minutes, and it started up fine like nothing had happened, wheeled it 2 more days after that without issue..

Come to think of it, that's the same hill I broke a tie rod on a few weeks ago... That hill is just bad luck.

 

[Eric L]

Yeah, I absolutely could be wrong, but it does seem like several variables need to be met before it kicks in. Kinda like how the anti-hop doesn’t step in and kill your engine without being at a certain angle upward. Once we disabled that the Bronco has never again died while trying to climb something whereas other rigs without that disabled and similar set ups did have the engine die. On the third obstacle of the pickle in Moab both. @NORCALGXP and wifey must have met the conditions necessary to limit back the Torque. As both got into a situation where the Bronco would not go over a certain RPM. He got through it by backing up and using copious amounts of throttles, we got through it by picking a different line.

Strange

 

[SierraBronco]

Strange

Were you against anything that was preventing movement?

 

[Eric L]

Were you against anything that was preventing movement?

No. It was a pretty straightforward climb

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