'93 Northstar S061 Suspension Sensor

[Captainhepp]

Hey folks, I have a '93 Eldorado Sport that I've had for some time, but just started doing things....

It's got a few issues, but I'm going to focus on just one here. It's intermittently flashing "Service Ride Control" or something along those lines. The code I found is S061. "Right front positions sensor fault?" I'm familiar with how to navigate through the DIC and am usually a DIY person.

I've done some research online but found nothing really definitive. What gives? Can I fix this without pulling/replacing the front strut. That would be a very bad day... :-)

Thanks in advance!

Mark

[Texas Jim]

If you haven't already done so... check the wiring and plug in connector on the right front wheel.

It could be just a dirty or loose connector.

[Barry94]

There are SEVERAL things that can cause the "Service Ride Control" message to be displayed.

You first need to be absolutely sure what component is causing the fault.

Error S061 has nothing to do with the struts. It only involves the position sensor.

These position sensors fail frequently. They are expensive to replace.

Both my front position sensors failed on my '94. I could not give GM

$500.00 each for $25.00 worth of sensors. So I "bypassed" the sensor to keep the

computer "happy"..

If you check out the wiring and also see if the actuator arm is still connected, and it still sets a code, then likely

your sensor has failed.

The following is a procedure to bypass a failed position sensor.

There are three wires to the sensor.

Each sensor has a "supply" voltage, usually 8V DC.

Each sensor has a ground wire.

Each sensor has a "signal" output back to the computer.

When the signal goes outside of it's operating range (Operating Range 0 - 5V), the computer

will report a fault with that sensor.

The front position sensors work on an output signal of 0 - 5V, where 2.5V is the "normal"

output for the sensor when you are driving normal on a flat road.

What you need to do is to provide a constant 2.5v voltage to the "signal" line of the sensor.

The computer will think you're driving on flat level road. (forever)

You do this by removing the sensor from the car and removing the clear "filler" that covers

the circuit card in the sensor. I used a sharpened popsicle stick. (Didn't want to destroy anything by using a metal object)

Expose the three wires entering the sensor.(On the front Position sensors, Purple=8V, Black=Ground, Orange=Signal back to the computer.

Cut them from the circuit card.

Attach one end of a 220 Ohm 1/4 watt resistor to the Purple=8V wire.

Attach the other end of the resistor to the Orange=Signal wire.

Also attach a Zener Diode (2.5V rating) to the Orange=Signal wire, and the other end to Black=ground.

(Resistor & Zener Diode available from a electronics store, eg. Radio Shack)

This will provide a constant 2.5V reference to the computer.

(After you have tested it.)

Seal up the sensor with lots of RTV to provide a water/weather tight area of the repair.

The computer will never complain again about the sensor.

If you are looking for an "easy" fix, then perhaps this is not it.

It is however a very inexpensive fix.

You do need a little understanding of soldering wires.

The ideal thing would be to acquire the male/female connectors that are on the sensor and build the

circuit in those. Then you simply could unplug the faulty sensor and plug this between the

existing harness and the faulty sensor.

You should be able to use this method to "fool" the computer on almost any of the RSS sensors.

Good Luck.

If you have questions, just let me know.

[Captainhepp]

This is intriguing. I will definately keep this in mind. Thank you so much for your time!

I had thought that it was possible to overide this sort of thing just by fiddling with the computer DIC, but I've since learned that isn't possible. Oh, well.

Your idea is probably what I'll follow. I'll likely do it on both side just to be even. Yes, I'm that picky. Do you have a picture of the sensor so I know what it is I'm looking for? I haven't found any online, yet. Thank you so much!

BTW, I am a computer, Piano, and Violin Technician. As such I usually do my own work on my cars. Just FYI. No worries. Thanks again!

[Barry94]

This is intriguing. I will definately keep this in mind. Thank you so much for your time!

I had thought that it was possible to overide this sort of thing just by fiddling with the computer DIC, but I've since learned that isn't possible. Oh, well.

Your idea is probably what I'll follow. I'll likely do it on both side just to be even. Yes, I'm that picky. Do you have a picture of the sensor so I know what it is I'm looking for? I haven't found any online, yet. Thank you so much!

BTW, I am a computer, Piano, and Violin Technician. As such I usually do my own work on my cars. Just FYI. No worries. Thanks again!

Sorry, I couldn't find any pictures of the sensor.

It's a black (approx) 1.5" x 4" x 1" "thing", attached to the front strut, with a wire attached.

There is also a "plastic rod" attached to the sensor that is attached to the lower control arm.

It's very obvious when you look in that area.

(It's not part of the strut, just attached to it)

I didn't think a '93 had these position sensor ???

Barry

[scott y]

Excellent info Barry.. I'll likely get onto that this weekend. Thanx,Scott

[Captainhepp]

I was poking around underneath for a minute earlier today and I think I found it. Thanks!

Yes, I have a 93 Eldorado Sport with the (actually vary rare for this car) non-HO 4.6L Northstar. It does have all the bells and whistles of an ETC except the moonroof (which I would LOVE), dual-zone climate control and a memory driver seat. Everything else is there. Speed-sensitive, road-sensing suspension (and speed-sensitive steering), etc. is all on that list. Dang if this isn't a complicated car... :-)

Cadillac values their sensors at $562 right now, so I'll be following your advice on hot-wiring. Thanks again!

[BodybyFisher]

There are SEVERAL things that can cause the "Service Ride Control" message to be displayed.

You first need to be absolutely sure what component is causing the fault.

Error S061 has nothing to do with the struts. It only involves the position sensor.

These position sensors fail frequently. They are expensive to replace.

Both my front position sensors failed on my '94. I could not give GM

$500.00 each for $25.00 worth of sensors. So I "bypassed" the sensor to keep the

computer "happy"..

If you check out the wiring and also see if the actuator arm is still connected, and it still sets a code, then likely

your sensor has failed.

The following is a procedure to bypass a failed position sensor.

There are three wires to the sensor.

Each sensor has a "supply" voltage, usually 8V DC.

Each sensor has a ground wire.

Each sensor has a "signal" output back to the computer.

When the signal goes outside of it's operating range (Operating Range 0 - 5V), the computer

will report a fault with that sensor.

The front position sensors work on an output signal of 0 - 5V, where 2.5V is the "normal"

output for the sensor when you are driving normal on a flat road.

What you need to do is to provide a constant 2.5v voltage to the "signal" line of the sensor.

The computer will think you're driving on flat level road. (forever)

You do this by removing the sensor from the car and removing the clear "filler" that covers

the circuit card in the sensor. I used a sharpened popsicle stick. (Didn't want to destroy anything by using a metal object)

Expose the three wires entering the sensor.(On the front Position sensors, Purple=8V, Black=Ground, Orange=Signal back to the computer.

Cut them from the circuit card.

Attach one end of a 220 Ohm 1/4 watt resistor to the Purple=8V wire.

Attach the other end of the resistor to the Orange=Signal wire.

Also attach a Zener Diode (2.5V rating) to the Orange=Signal wire, and the other end to Black=ground.

(Resistor & Zener Diode available from a electronics store, eg. Radio Shack)

This will provide a constant 2.5V reference to the computer.

(After you have tested it.)

Seal up the sensor with lots of RTV to provide a water/weather tight area of the repair.

The computer will never complain again about the sensor.

If you are looking for an "easy" fix, then perhaps this is not it.

It is however a very inexpensive fix.

You do need a little understanding of soldering wires.

The ideal thing would be to acquire the male/female connectors that are on the sensor and build the

circuit in those. Then you simply could unplug the faulty sensor and plug this between the

existing harness and the faulty sensor.

You should be able to use this method to "fool" the computer on almost any of the RSS sensors.

Good Luck.

If you have questions, just let me know.

Very Cool Barry! We need to bookmark this thread someplace

[scott y]

I fully concur

[Barry94]

I finally found the diagram I made when I bypassed the sensors. This should help as well.

Barry

[Captainhepp]

Here's another thought....

This could just be me not knowing my electronics, but...

Would it be possible to vary the resistance manually? Would so doing in effect manually control the damping level of the suspension? Just a thought. :-)

Mark

[Captainhepp]

"Attach one end of a 220 Ohm 1/4 watt resistor to the Purple=8V wire.

Attach the other end of the resistor to the Orange=Signal wire.

Also attach a Zener Diode (2.5V rating) to the Orange=Signal wire, and the other end to Black=ground.

(Resistor & Zener Diode available from a electronics store, eg. Radio Shack)"

I can't seem to get my hooks on a 2.5V Zener locally (Radio Shack only had 5.1V in their system). Haven't ruled out an online supplier, but I was wondering...

Would a Voltage divider do the same basic thing? As in, made out of simple resistors? Just a thought. Thanks!

Mark

[Barry94]

Here's another thought....

This could just be me not knowing my electronics, but...

Would it be possible to vary the resistance manually? Would so doing in effect manually control the damping level of the suspension? Just a thought. :-)

Mark

Mark,

The suspension control is not too sophisticated. The struts only have three positions, soft, medium, firm.

Soft is set automatically when under approx 30 mph (forget exact number).

Medium is the next setting, to approx 30 to 50.

Firm setting is around 50-60 mph.

The position sensors are there to "over ride" the strut's normal settings. Example -- In a sharp turn, a compressed or extended sensor will switch the strut to the "firm" setting, aiding in controlling the vehicle.

As the sensors are compressed or extended, they will change the strut firmness.

Both my front position sensors were "modified". I never noticed any difference in handling or ride.

Adjusting the struts manually, through the sensor settings is possible, however, it's not a variable result.

Note... When a position sensor fails, the automatic setting for the struts is the "firm" setting, all the time. Creates a bit of harsh ride when driving slow.

Barry

[Barry94]

"Attach one end of a 220 Ohm 1/4 watt resistor to the Purple=8V wire.

Attach the other end of the resistor to the Orange=Signal wire.

Also attach a Zener Diode (2.5V rating) to the Orange=Signal wire, and the other end to Black=ground.

(Resistor & Zener Diode available from a electronics store, eg. Radio Shack)"

I can't seem to get my hooks on a 2.5V Zener locally (Radio Shack only had 5.1V in their system). Haven't ruled out an online supplier, but I was wondering...

Would a Voltage divider do the same basic thing? As in, made out of simple resistors? Just a thought. Thanks!

Mark

Mark,

Any method to arrive at 2.5v would work. Even a battery pack with a pair of rechargeable AA would work.(2.6v)

The object is to keep the voltage stable around 2.5 volts.

A voltage divider would work if you can maintain a constant 2.5 v. Voltage dividers output will depend on the "load", however, the load should not vary

as this is a signal input to the computer. I can't verify that, just assuming.

The reason to keep the voltage stable is that if it varies too much, then the struts will constantly be switching ride positions.

Barry

[Captainhepp]

That all makes sense. Thanks a bunch!

[el_dorado_mex]

this thread was of great help, thanks barry!

i'd like to share what i did today (and worked well in my case), just because of being sunday and not be able to get resistances and/or diodes.

let me explain my case first:

'96 eldo, right front height sensor quit working (gives like a constant 6V signal), all the others work well. and there are passive struts front, original rear.

so first i put in some 10 ohm, 25 watts to pretend the strut actors are there. nothing to do with the height sensor, but with the method i used to fool the broken one.

then i thought on how may i get a 2.5V signal to the right side signal line... so i came up with a relatively easy fix, i spliced in a wire to the left side signal wire (that sensor works), and connected it to the right signal line (sensor disconnected). and that's pretty much it, now the computer thinks that both sides have the same height all the time, but it still varies. probably it gets a tad off the real value, since voltage drops slightly by sharing the signal. anyhow, no big deal with passive struts. additional recommendations:

don't do that with active struts built in, since you'll loose the suspension ability to correct shock stiffness while taking close turns.

only applicable if one of both sensors still works well.

you have to disconnect the broken sensor, if you don't, signals (voltages) interfere with each other, making the computer think both are off value.

not the most elegant solution, but works fine for me at that time, all codes disappeared.

thanks again barry for explaining how that system works, that was a great help!