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Discussion Starter #1 (Edited)
Hi,
A good friend has replaced his chassis that had the 3 bolt hole height sensors for a later chassis that uses the 2 bolt hole.
I got involved to fit the new sensors and re wiring needed to sort the eas out.

The problem is that the height is too high on the front, but ok on the back !

I know about re trimming the target settings in the suspension ecu, but the front height difference is more than that.

The access, motorway, and normal settings do adjust and set properly (with the greater height offset on front), but the extended setting cannot be set due to mechanical limitations (shock absorber topping out).

As the 4 height setting prior to chassis change, and on the old sensors, were fine, I am wondering what is causing this issue ?

All the new 2 bolt sensors and wiring are correct, so does the later p38 use a different shaped radial arms, so the sensor arm bolt hole is in a different height position to the earlier one ?

Please advise,

Paul.
 

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Sounds your trying to gain to much at 'extended' profile, what values are you trying to enter? Having fitted later front sensors to early chassis there was no issue, didn't even recalibrate.
 

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1995-2002 Range Rover P38A
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Did he change to a later EAS ECU as well?

The reason I ask is that when I went back to air in mine (a 1995), I'd been sent later sensors and no way could we get it to calibrate properly. Finally tracked some '95 specific ones and it was sorted immediately. I can't remember the year they changed ('97?), but an early ECU and later sensors don't appear to talk to each other very nicely.
 

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Discussion Starter #4
Thanks for the feedback.
The settings in the eas box have not been altered, if the height was out by say 1cm I can understand changing target values for tolerance issues.

As both front left and front right are approx 5+cms high on all height presets (access/motorway and std) there is clearly some mechanical offset that has yet to be identified.

Regarding the eas ecu, there are 2 versions (anr3773 and anr4489), these are interchangeable so not dependant on vehicle age.
IIRC the later anr4483 is a factory upgrade dealing with reliability issues, so it just supercedes the other.

The plot thickens !

Paul.
 

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1995-2002 Range Rover P38A
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I have a feeling that the offset on the arm between the earlier 3 bolt sensors and the later 2 bolt sensors are different.

Part number wise, the original 3-hole version is part no: ANR2494, however these are superceded by 2 part numbers - one for left, one for right.
STC3579AA is listed as the updated part number for the RH side
STC3578AA is listed as the updated part number for the LH side.

A google search of those part numbers shows a 2-hole sensor, with a pigtail harness - and a mounting bracket - which I am guessing bolts onto the chassis, and then the studs on the bracket are set at the correct angle to attach the newer style sensor to.

As you are going the other way - trying to fit older sensors to newer chassis bolt pattern, you will probably have to make an adapter bracket to adjust the sensor offset a bit.. I doubt the offset is a lot though, so it might be easy enough to make a couple of metal brackets that bolt onto the chassis in the 2 holes that are there, and then be able to offset the angle of the older sensor fairly easily.

Either that or look at upgrading the front sensors to the later type - which are universal fit Left/Right ANR4686 is the part number.

That wouldn't be the cheapest option, but it would probably let you calibrate it straight off.

There is only one part number for each of the LH/RH radius arms - so it won't be a change there - it must be something to do with the sensor - either the arm length, or the mounting angle.

Hope this helps,
Marty
 

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The OP mentions twice that he's fitting new [type] sensors.

OP, If your fitting new sensors and new chassis, but still old ecu, have you recalibrated? (photo might help too)
 

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Ah, I missed the bit about new sensors being fitted.

Are they brand new sensors, or are they second hand sensors that are 'new' to the vehicle/project?

It doesn't look like there has been calibration done:

Thanks for the feedback.
The settings in the eas box have not been altered, if the height was out by say 1cm I can understand changing target values for tolerance issues.Paul.
So yes, that would be the next thing to check
 

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Discussion Starter #8
Yes the sensors are all brand new, bought and fitted by myself.
I have done some calcs for the point vs height change, and is approx 1.6mm per point, so 10 points will change height 16mm, or there abouts.
As the target setting would have to be altered very close to the minimum accepted values, this to me is not the right method to go about the problem, I would be happier to find what is causing the front height issue.

The accepted front target limits for the eas box are high =120 to 180, and std =95 to 150.
As the previous stored target settings are 156 for high and 130 for std, I would have to set high target value to approx 130 or less, to get in the ball park.
All the other target values would also have to be re set accordingly.

This seems to me a poor way to cover up another problem.
Just for my own piece of mind I will swap the eas ecu over, just to see if by chance the eas box is partially faulty.

Paul.
 

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Discussion Starter #9
Yes all the sensors are brand new bought and fitted by myself.
ANR4686 on front and ANR4687 on rear.

I did some calculations on the target height values, and 1 point = approx. 1.6mm, so to drop the front by 50mm would need 30 deducted from the target values.

The eas ecu software target limits for front are high = 120-180, and standard height of 95-150.

As the current target front high settings are 156, this would have to be reduced to 126.

126 is very close to the minimum lower target accepted limit for high setting, this to me is a fudge compared to finding out the real problem.

Also remember all the other settings (access/motorway and std height settings) would all have to be altered similar !

I have previously made 4 sets of height blocks to calibrate the exact heights, but before I do this I can see this that the target values obtained by this are going to be unusual to say the least.

Paul.
 

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Define unusual? Are the values within spec. or not? There's no photos to help us, so either the calibration will take or the installation is wrong or something with the rest of the EAS has some currently unknown issue.
 

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Discussion Starter #11
Ok update on the front height issue.

Replaced the eas ecu from a working range rover, straight away the car front and back heights looks level.
With identical set target levels entered on both boxes, front sets 5cm+ on original unit, whilst the donor box looks fine.
So now kept donor box in car and got the height blocks out, right front sensor reads 10 points lower on right, compared to front left.
Back left and right values are 3 points different.

So this is far better.

Paul.
 
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