Thread: How D4 Suspension handling on corrugation and Simpson?

Gday Gary.

I havent done those sorts of trips yet, but many on here have. Most of them take a diagnostic tool (Nanocom or Gap IID tool seem popular) which can read and clear fault codes. It can also raise and lower the suspension, which can be handy if your car limits itself to "normal" height, but wont help if it decides to sit on the bump stops.

One handy trick is a "hard reset". Once the car is "asleep" (the park brake light goes out) Disconnect the battery terminals as per the manual, and grab a screwdriver or spanner and connect the positive and negative wires together. DO NOT SHORT THE BATTERY TERMINALS. Just the wires. This removes any residual current from the computers, essentially resetting them.

Put it all back together and start it up. Hopefully the problem will have disappeared! If not, you may have a persistent issue.

I have seen the hard reset work on a D4 that had a height sensor issue after a water crossing, which caused the car to drop to the bump stops on rough ground, stopping all movement. It took about 5mins for the compressor to pump the car back up but it was fine for the reat of the day!

Hope that helps

Dan

Originally Posted by DIS4

I had always dreaming to have my D4 on Simpson or Cape York one day, but many of those Toyo Fans keep telling me that air suspension will not able to handling the long corrugation. I learnt more each day about my D4, also realized how little I understand what my D4's capability. So often, I know that D4 is capable to bring where ever I want to go if I have enough knowledge about it and prepare to do minor repair if it fails. However, I still encounter many suspension issues so far, many reset by restart the engine and but need to know how to diagnosis it. Just came back from Fraser Island recently, another early D4 had error message of " can not raise suspension due to high temperature" after it sudden drop 0.5m on undetected river creek. would it shock the sensor in this way? We couldn't reset it after tried to pull out the fuse, it once drop to access height and but corrected by pulling out fuse. Even though, the off road height can not be selected due to error message. Will a diagnostic tools solve the issue?

I will not fully committed to a long trip without equip myself with necessary knowledge and tools. Any knowledge and feedback on your experience are much appreciated? Once I thought to have second trucks to do the hardcore offroads and handling the corrugation, but just don't want second cars to sitting outside the garage since miss refuse to drive my D4.

Cheers,

Gary

Yep those toyota blokes are the experts after all, if someone that has never owned a vehicle, makes a comment on that vehicle, then I tend to ignore that person.

Never had an issue with corrigations, never heard of that error message either, I've crossed 100 creeks, from axle height to bonnet height, never had an issue, I did have a height sensor go and it put up a suspension fault, it had exposed wires, so I'd assume it had contact with something, but it never stopped the car, just press the OK button and continue, reset the car once you stop next, not a problem really, plug in your diagnostic thingy to find the fault code, it will tell you what sensor is the problem, get it replaced when you get the opportunity, for us it was when we got home a couple of weeks later.

A diagnostic tool won't fix the issue, but it will give you an idea of whether it's a serious issue or not, either way you can clear the fault to get you mobile again, a serious problem will put up a different light colour, minor issue is yellow, serious issue red, red means get it looked at ASAP, there's not many faults that will stop you dead, especially if you have a diagnostic tool with you, 9 times out of 10 most issues are minor, that 1 out of 10 will mean get to a mechanic ASAP and that's where the Diagnostic tool will help, keep in mind LRs are not the only vehicle that has that 1 out of 10 moment, they are a pretty tough 4WD, so don't worry too much about the vehicle failing, remember the glass is half full

Baz.

Yeah done plenty of k's with corrugations, a D3/4 is a godsend in those conditions. Other makes are feeling the pain while you are comfy!
Done the Simpson and a really tough diversion to the Geographical Centre. The early D3 was awesome, the women on the trip always wanted a ride in the Disco!

You can't get a better car for corrugations, other than perhaps a Range Rover Vogue. Corrugations are never an issue for the D4. As Rich said, you travel in comfort while your friends in their 200 Series Toyos or Patrols suffer and complain about them.


Water crossings may be a bit different as there are things that can get wet that shouldn't get wet. However, if you are careful and respect that there are electronics under the bonnet that need to be kept dry there is no problem. I have had water up to bonnet high on several crossings without an issue. Everything under the hood stayed dry due to the seals that provide an air pocket under the hood for a reasonable time.

Remember on corrugations never be the lead car if Toyotas are traveling with you.

You'll be forever having to stop to let them catch-up.

Having done lots of outback trips (Simpson x2, A.b. Hwy, Talawanna, and Madigan line last year, in our D3 Have not had a problem with air suspension.
Actually there is one problem and that is because of the good ride you tend to travel too fast which becomes an issue when you suddenly come across a hidden washout or dip. The suspension on occasions can become confused such as suddenly dropping into a hole, but this usually resolved by lifting and lowering the suspension a couple of times. This can also happen after the car has been on the hoist at the garage. One thing that may cause concern is in the morning when it looks like the suspension has dropped overnight. . Travelling slowly over rough sand.hills the air heats up and expands, then the air in the airbags contracts with the drop in temp on a cold night and lowers the car.

Ivan

Originally Posted by IvanR

because of the good ride you tend to travel too fast which becomes an issue when you suddenly come across a hidden washout or dip.
Ivan

That is very true Ivan. Also, the one thing that the air sprung Discos don't like in my experience is small sharp dips across the road. The front suspension bottoms with a big crash whereas live axle cars barely feel it. Travelling with my son in his D1 we often have discussions on the radio about that big hit that I had which he didn't even feel!

Originally Posted by Disco-tastic

One handy trick is a "hard reset". Once the car is "asleep" (the park brake light goes out) Disconnect the battery terminals as per the manual, and grab a screwdriver or spanner and connect the positive and negative wires together. DO NOT SHORT THE BATTERY TERMINALS. Just the wires. This removes any residual current from the computers, essentially resetting them.

Put it all back together and start it up. Hopefully the problem will have disappeared! If not, you may have a persistent issue.

I have seen the hard reset work on a D4 that had a height sensor issue after a water crossing, which caused the car to drop to the bump stops on rough ground, stopping all movement. It took about 5mins for the compressor to pump the car back up but it was fine for the reat of the day!

Simply disconnecting the battery for a second or 2 will cause all ecus to restart their logic. Joining cables together only takes extra time and invites short circuits if a dual battery system is fitted that maintains battery connections after engine stop.