Hello,

I have been working to fix the flashing up arrow and E-W lights on my 98 S90.

I have:

1. replaced the PNP switch

2. checked the transmission speed sensor. (my ohm meter reads 567 ohms within the acceptal range of 300 to 60. I have pulled the sensor and I can not see any physical damage on the sensor.)

3. I have jacked the rear of the car up. The car is on jackstands. The rear tires are hanging about 1 inch above the floor. I can see the sensor on the differential but I do not know what has to be done to reach the sensor.

What do I need to do to be able to safely reach the sensor to test its ohm resistance and to inspect the wiring and remove and inspect the sensor?

Don67

inside the trunk, there should be a little black box about 2" x 3" clamped over some wires. That is the tamper-evident box covering the connection between the main harness and the wires to the sensor on the diff. You may find it a lot easier to test the resistance there than at the actual sensor.

You should definitely check the integrity of the wiring to the diff--both visually and electrically. The insulation crumbles and it can short itself out, or the stranded copper wire can severely corrode once the insulation is gone.

john
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1989 245 245K / 1993 945 131K

John,

Thank you for the reply and suggestions.

I found the adhesive on the tamper-proof box to be very strong.

My ohm tester showed 1260 ohms which is way out of the acceptable range of 300 to 600 ohms.

I have been under the car looking for a way to reach the sensor and the clip on the sensor.

I am having trouble. I have a short stocky hand and can only touch the bottom edge of the sensor with the tip of my finger.

Do I need to remove any thing to make it easier to reach sensor?

I am thinking that I may need to get a very long slander pair of needle nose pliers to reach the clip and sensor.

Thanks for the earlier reply. I hope you can suggest a way to reach and replace the sensor.

Don