BACK-UP SENSOR DIAGNOSIS AND REPLACEMENT
What Is It?
====
The back-up sensor tells your car that you have shifted into reverse. Your car then turns on your back-up lights. Physically, the sensor is a couple pieces of metal with two wires coming out. There are pictures for you visual types later.
Symptoms
====
The symptoms are your back-up lights not working. These are the lights in the taillight assembly that light up white when you shift into reverse. If only one of them isn't working, check your bulbs; this DIY doesn't apply to you.
Where Is It?
====
The back-up sensor is located on top of the transmission, underneath the end of the distributor cap.
(Note: I have a manual transmission, the position might be slightly different on an automatic.)
Diagnosis
====
It's very easy to diagnose whether or not the problem is your back-up sensor.
The sensor has two wires coming out of it. Disconnect these wires from the main harness by unplugging them. Then plug the two wires from the harness together and start the car. Your back-up lights should be on all the time. If they aren't, then this DIY doesn't apply to you.
If they are on while these wires are connected, the problem is your back-up sensor.
Replacing The Back-up Sensor
====
Tools: 3/4" open-ended wrench
1. If you haven't followed the diagnostic step, unplug the sensor from the wiring harness.
2. Move the sensor's rubber boot so you can get at the flat sides of the sensor that allow you to fit a wrench on it. If you are replacing the sensor, feel free to cut the boot with a knife; your replacement should have a boot in much better shape. Otherwise, you might be able to pull it up a bit to
allow access with a wrench.
2. Unscrew the sensor with an open-ended wrench. These sensors have an annoying "feature" where the rounded top of the sensor is wider than the six-sided portion. This forces you to come nearly straight on with a wrench, which is much more awkward than it should be.
3. When replacing the sensor, make sure to replace the washer between the sensor and the tranny. Don't install the sensor without a washer because it affects the throw of the sensor tip.
4. Tighten the new sensor to 18 ft. lbs. If you can't get a torque wrench in there, take solace in the fact that I just estimated with a normal wrench and have had no problems after 10,000 miles.
5. Plug the two wires back in.
You're done!
Pictures
====
No DIY is complete without pictures. Here's my journey into my back-up sensor....
My bad back-up sensor with the rubber boot pushed up the wires.
Well, I think we can all tell what the problem is.
Ooh, shiny! Note the convenient plugs that allow you to diagnose the problem too.
Fresh new back-up sensor installed in my car.
Regards,
Ghostyman
What Is It?
====
The back-up sensor tells your car that you have shifted into reverse. Your car then turns on your back-up lights. Physically, the sensor is a couple pieces of metal with two wires coming out. There are pictures for you visual types later.
Symptoms
====
The symptoms are your back-up lights not working. These are the lights in the taillight assembly that light up white when you shift into reverse. If only one of them isn't working, check your bulbs; this DIY doesn't apply to you.
Where Is It?
====
The back-up sensor is located on top of the transmission, underneath the end of the distributor cap.
(Note: I have a manual transmission, the position might be slightly different on an automatic.)
Diagnosis
====
It's very easy to diagnose whether or not the problem is your back-up sensor.
The sensor has two wires coming out of it. Disconnect these wires from the main harness by unplugging them. Then plug the two wires from the harness together and start the car. Your back-up lights should be on all the time. If they aren't, then this DIY doesn't apply to you.
If they are on while these wires are connected, the problem is your back-up sensor.
Replacing The Back-up Sensor
====
Tools: 3/4" open-ended wrench
1. If you haven't followed the diagnostic step, unplug the sensor from the wiring harness.
2. Move the sensor's rubber boot so you can get at the flat sides of the sensor that allow you to fit a wrench on it. If you are replacing the sensor, feel free to cut the boot with a knife; your replacement should have a boot in much better shape. Otherwise, you might be able to pull it up a bit to
allow access with a wrench.
2. Unscrew the sensor with an open-ended wrench. These sensors have an annoying "feature" where the rounded top of the sensor is wider than the six-sided portion. This forces you to come nearly straight on with a wrench, which is much more awkward than it should be.
3. When replacing the sensor, make sure to replace the washer between the sensor and the tranny. Don't install the sensor without a washer because it affects the throw of the sensor tip.
4. Tighten the new sensor to 18 ft. lbs. If you can't get a torque wrench in there, take solace in the fact that I just estimated with a normal wrench and have had no problems after 10,000 miles.
5. Plug the two wires back in.
You're done!
Pictures
====
No DIY is complete without pictures. Here's my journey into my back-up sensor....
My bad back-up sensor with the rubber boot pushed up the wires.
Well, I think we can all tell what the problem is.
Ooh, shiny! Note the convenient plugs that allow you to diagnose the problem too.
Fresh new back-up sensor installed in my car.
Regards,
Ghostyman
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