LX won’t raise from Low to N with trailer attached - stuck in a raise/drop loop (1 Viewer)

[trudd]

Currently on the road, but this may become a RTH situation.

When attaching my Intech Explore trailer, I drop into Low mode, attach the trailer, and then raise to Neutral. Never had a problem on my first ‘09 LX.

In my ‘10, it sometimes gets stuck in a loop where it tries to raise and drops back down. It might happen 2-3 times and then eventually resolve. Originally I thought this had to do with having the e-brake engaged.

This past weekend, it got stuck in an indefinite loop. The weirdest part is that both the LX and trailer were essentially empty. Both are usually fully loaded when I hitch up. See the video:



I’ve serviced AHC earlier this year, so it has new globes, fresh fluid. It operates flawlessly otherwise.

Factors worth mentioning:

• trailer is 1,750lbs dry. It’s a toy hauler, so the tongue weight is pretty high out of the gate but I don’t have an exact measurement.
• I’m using a 5” drop hitch. I’ve heard more drop might increase stress on rear suspension? The trailer is perfectly level at this drop, but I have a 3.5” drop I can try if needed
• I have not checked AHC fluid level, but it goes into high mode no problem. I don’t suspect fluid being the issue.

To resolve the issue this time, I put the LX into neutral before hitching and slowly lowered the hitch to let AHC adjust incrementally. It did do the lower/drop reset once, but towed fine once settled.

I don’t have Techstream handy and I left my OBD adapter at home, but I’ve never seen any codes in the dash or via OBDFusion.

So, where would you start with troubleshooting?

 

[TeCKis300]

It's seeing too high of hydraulic pressure. The question is why.

• Hard to tell but is the LX on an incline where weight is shifted to the rear axle?
• Toy haulers tend to have really high tongue weight empty with the expectation that laden it'll counterbalance and actually reduce tongue weight.
• Are you sensor lifted. (looks like not?)

Not all is lost and some key things well minimize this issue dramatically. My airstream is 1200lbs tongue and has no problem lifting to normal. I can generally lift into high too (unless I'm on an incline that shifts load to the rear axle.

• Modify or replace that drop hitch to bring the ball tighter to the bumper. Not less drop, but pulling in that ball close to the bumper horizontally. This reduces leverage, which also creates a shifting of load from the vehicle front axle to rear axle. You might be able to drill another hole for the hitch pin to push the drop hitch farther in (which might require cutting the shank too). Even 1" here will make a good impact to lifting, but also towing stability. I personally would replace it with a hitch that drops straight down instead of an angle that pushes the ball further rearward.
• Install a 15mm spacer to the rear coil springs. This should have almost no negative effect when unladen, but will create additional margin for AHC to lift loads

 

[eatSleepWoof]

Why is the tongue jack down/vertical?

What if:
1. LX pumps too much pressure, realizes it's too high
2. Drops in an attempt to get level, tongue jack contacts the ground
3. Continues dropping, but now tongue jack isn't letting the trailer lower
4. LX thinks it has dropped too low, goes back to step 1

 

[trudd]

I did do a minor 1” AHC height offset to the rear driver side to try to account for lean (they side had an existing -0.9” ahc offset for some reason). That post is in my history and I believe I tapped you in on it.

I did experience this issue prior to that adjusting that offset.

I’ll prob install a 10mm space in the rear driver spring and bring it back to stock height/offsets.

Heard on the hitch. Perfect idea to send to Santa.

 

[trudd]

Why is the tongue jack down/vertical?

What if:
1. LX pumps too much pressure, realizes it's too high
2. Drops in an attempt to get level, tongue jack contacts the ground
3. Continues dropping, but now tongue jack isn't letting the trailer lower
4. LX thinks it has dropped too low, goes back to step

Why is the tongue jack down/vertical?

What if:
1. LX pumps too much pressure, realizes it's too high
2. Drops in an attempt to get level, tongue jack contacts the ground
3. Continues dropping, but now tongue jack isn't letting the trailer lower
4. LX thinks it has dropped too low, goes back to step 1

Notice that the hitch isn’t locked either, so the ball can exit the hitch if it drops down too low. I did this in case I experienced this issue. Last thing I wanted was to be stuck in low and unable to get the tongue jack folded back out.

 

[tbisaacs]

I’d feel much better if you checked the AHC fluid level. Rule out the obvious. I had an issue where my truck wouldn’t go into high, had a mild panic attack, started looking for trouble codes, texting friends, and in the end the fluid was a few mm below the line

 

[trudd]

Back on the grid after some days camping. Had the same cycle this morning when hitching up, but I was in neutral mode the whole time.

To break the up/down cycle, I took all weight off the ball by jacking up the trailer, let the LX stabilize in N mode, then pressed the AHC button into high mode. It went into H mode, with trailer attached, no problem.

I drove off, let the rig settle into N mode naturally and alls been fine.

@TeCKis300 — thinking that I need to undo the AHC offset I added to the rear driver side, and add a 10mm spacer to that spring.

 

[eatSleepWoof]

I took all weight off the ball by jacking up the trailer, let the LX stabilize in N mode, then pressed the AHC button into high mode. It went into H mode, with trailer attached, no problem.

I drove off, let the rig settle into N mode naturally and alls been fine.

The above is how I hook up my travel trailer.

Put the truck into H and leave AHC on, hook up the TT, put the truck into N and drive off, leaving AHC turned on.

When I disconnect, I put the truck into L, turn off AHC, then disconnect the trailer, level it, etc.

 

[trudd]

@TeCKis300 revisiting this issue after a while. It's still happening, though it resolved faster when I used a hitch with less drop. Now it's time to talk about spacers, especially because I might be upgrading to a bigger camper.

I have two OME 10mm spacers on order from Cruiser Outfitters. I was planning on putting one spacer on the RL coil spring to give AHC a little help and level the rig, however a local friend and Mud Mechanic has a ~32mm spacer in his shop.

Level-wise, I think I'd be good with one 10mm spacer on the RL spring, however what do you think about stacking both OME spacers to add 20mm of height to the RR spring and the ~32mm spacer on the RL spring? This would give the desired ~10mm boost to the RL spring, and an added 20mm of spring support on both sides, hopefully nipping this towing issue in the bud.

My goal here is not a lift, just some support to help AHC get back to normal under load. Thoughts?

 

[grinchy]

Seems like you’ve got a good use case for airbags

 

[TeCKis300]

@TeCKis300 revisiting this issue after a while. It's still happening, though it resolved faster when I used a hitch with less drop. Now it's time to talk about spacers, especially because I might be upgrading to a bigger camper.

I have two OME 10mm spacers on order from Cruiser Outfitters. I was planning on putting one spacer on the RL coil spring to give AHC a little help and level the rig, however a local friend and Mud Mechanic has a ~32mm spacer in his shop.

Level-wise, I think I'd be good with one 10mm spacer on the RL spring, however what do you think about stacking both OME spacers to add 20mm of height to the RR spring and the ~32mm spacer on the RL spring? This would give the desired ~10mm boost to the RL spring, and an added 20mm of spring support on both sides, hopefully nipping this towing issue in the bud.

My goal here is not a lift, just some support to help AHC get back to normal under load. Thoughts?

By RR RL do you mean Rear Right and Rear Left? Not sure if I'ma understanding right but proposing an asymmetrical spacer setup? Not sure I'm do that.

No issue stacking spacers other that you'll need to make sure there centering lips that keep things in place. There is what called the spring isolator/jounce stop at the top of each spring. It's the cone looking rubber stop. You can put a 10mm spacer above that cone base between the chassis. And a 10mm spacer under that cone base in between the spring.

What you need is just more preload and 10-20mm of preload on each spring without sensor lift should be fine even unladen.

 

[coleAK]

Seems like you’ve got a good use case for airbags

Funny you mention this. I’m strongly considering airbags for my LX. I have a buddy that left AK and needed to liquidate, last week I ended up with a 2nd camper, one that had an articulating hitch and no way to really do a WD.

To the OP my Ahc lifted this one just fine and the TW is 700-800 lbs.

 

[CanadianRockyCruiser]

Currently on the road, but this may become a RTH situation.

When attaching my Intech Explore trailer, I drop into Low mode, attach the trailer, and then raise to Neutral. Never had a problem on my first ‘09 LX.

In my ‘10, it sometimes gets stuck in a loop where it tries to raise and drops back down. It might happen 2-3 times and then eventually resolve. Originally I thought this had to do with having the e-brake engaged.

This past weekend, it got stuck in an indefinite loop. The weirdest part is that both the LX and trailer were essentially empty. Both are usually fully loaded when I hitch up. See the video:



I’ve serviced AHC earlier this year, so it has new globes, fresh fluid. It operates flawlessly otherwise.

Factors worth mentioning:

• trailer is 1,750lbs dry. It’s a toy hauler, so the tongue weight is pretty high out of the gate but I don’t have an exact measurement.
• I’m using a 5” drop hitch. I’ve heard more drop might increase stress on rear suspension? The trailer is perfectly level at this drop, but I have a 3.5” drop I can try if needed
• I have not checked AHC fluid level, but it goes into high mode no problem. I don’t suspect fluid being the issue.

To resolve the issue this time, I put the LX into neutral before hitching and slowly lowered the hitch to let AHC adjust incrementally. It did do the lower/drop reset once, but towed fine once settled.

I don’t have Techstream handy and I left my OBD adapter at home, but I’ve never seen any codes in the dash or via OBDFusion.

So, where would you start with troubleshooting?

-A weight distribution hitch is probably worthwhile in your case. What is your tongue weight? I'd go buy a cheap one from harbour freight or facebook marketplace to "put through" until you can dial in your towing game
-Is your hitch level at "N" ride height? the drop looks way too low from the video, which will apply more tongue weight. You want the trailer frame horizontal to the ground (tough to tell from the video angle, but it looks low.