Temporary Sensor Bypass– OBD1 94 Deville SLS 4.6

[Paul]

94 Cadillac Deville SLS OBD1 code S061
Temporary fix the S061 code is the right front Ride Control Sensor. Was Getting 7.6 Volts DC input signal and nothing going from the sensor back to the computer. Tried using the fix using a 220 ohm resistor and diode, found on the web, NO Luck! There are 4 wires going into the sensor, Black, Green, Red, and Orange. The Black and Green are both Grounds, the Red is the 7.6VDC input and the Orange is the reference signal going back the computer.
Using an adjustable voltage regulator ( LM317T ) ic set at 2.65VDC. The Vin is the RED Wire, Vout is the Orange Wire, the Ground is the Black and Green Wires tied together, NOTE these wires are NOT the vehicle ground !!! Using 10K ohm resistor to replace the variable resistor and the fixed resistor. The 10k resistor is connected from the Vout to between Adjust and Ground pins of the ic. Using a 0.1uf capacitor connected to the Vin ic pin then to the (-)side of the 1uf capacitor the (+) end of the 1uf capacitor is then connected to the Vout ic pin.
The procedure was to disconnect the wire pig tail going to the sensor and then cut the wires off near the sensor leaving several inches of wire between the freed connector and cut wire. The small circuit was built on the bench and using a 9 volt DC battery to test and double check the circuit output. Then plugged in for a test drive.
Make sure to insulate between ALL ic leads and seal the circuit extra well and be sure to make a rugged project. The LM317T has an operating range of 0*-125*C so the idea was to route the circuit up near the engine to try to stay within the operational range of the ic, several cable ties attached it to the fuel line and free of all moving parts.
PARTS used …………………..
1) LM317T ic
1) 10K ohm resistor
1) 1uf capacitor
1) 0.1 uf capacitor
Thinking this over the same type circuit could be used to check other sensors malfunctions by using the proper output voltage.
banana:

Topic

[Joeseph Mama]

Let’s unravel some of the mystery…

To be honest, I am kinda overwhelmed here… there is a lot going on with a lot of resisters and amplifiers and what not.

Well.. to test this sensor, this is probably what I’d do:

• Pull the senor.
• Ohm test the sensor in the ‘home’ position. Compare to expected reading.
• Ohm test the sensor in ‘fully actuated’ position. Compare to expected reading.
• Make sure it is getting the correct 8 volt input. (wierd.)
• Apply the 8 volt reference to the sensor.
• If input is good, check the outputs:
• Check the sensor at the ‘home’ position and see if you get expected voltage.
• Check the sensor at the ‘fully actuated’ position and see if you get expected voltage.
• Ground circuit resistance should be below 10mV (ASE standard for sensors)
• Pull a known good sensor and compare the above results vs. the faulty sensor.
  [li]If possible, swap a bad sensor with a good sensor and see if the problem (or codes) follows the suspected bad sensor. If not, the problem may be somewhere in the affected circuit.

This is all just basic sensor circuit diagnosis… just to see if you can identify any problem area(s).

Of course, let’s not overlook the basics; here is just what one person said who had a similar problem:

I found that on both sides the small connecting rod was attached to the lower control arm but was dangling loose and not inserted into the boot on the level sensor unit arm. How they both came out is a mystery although my son did have to call AAA for a flat tire change this summer and they may have lifted the car in a way that dropped the front wheels enough to pull the arms out of the rubber boots. That is about the time that he first saw the service suspension message. (My son had the car this summer for his college internship and he is not mechanically inclined!) I reinserted both rods and cleared the trouble codes. The service suspension system message is now cleared and no trouble codes reappeared.

Attachments:

• activesusp.png

[Its me]

I believe if you check, the Cadillac uses an 8 volt electric feed for the level sensors. The fact that you are not getting anything back from the sensor makes me believe that you simply have a bad sensor. The previous post is a good way of diagnosis…

As stated above, you can manually test these sensors by disconnecting the arm and check the electrical responses… I understand what you have done, just think it was an overthought way to do it…

JMHO

-Karl

[Author]

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