I have a bad speed sensor from what my codes says and the car does show the symptoms - it's a 94 Accord EX AT. Can anyone give me advice and instruction on replacing this part? I believe the part number is 78410SV4003 but not positive. I do have an online copy of the service manual for this car but can't find the page for this because i can't find the correct dealer name for the part. Also, is it fine to buy and aftermarket sensor or does it really make a difference to have the OEM?

 

Look towards the firewall near rear mount, you will see a your speed sensor. Remove (1) 10mm bolt; disconnect the 3-wire connector and pull the assembly out. Your local auto part store should have the electronic portion (black part) for under $80. If you remove your assembly and the gear is mess up then your will have to get one from the dealer, online, or salvage yard.

 

Thanks. I thought there was supposed to be two bolts to remove. Are you saying I can remove only a part of the sensor and just replace that?

 

My sensor has 2 bolts on it as well and is in that area but more so under The intake mani on top of the tranny. I got mine off eBay for 25 bux shipped. There is a small gear in it. I got the electrical part with the gear for that price. I got a 94 with a 5 speed.

 

There is (1) 10mm holding the whole assembly to the transmission itself, but yes there is two to remove the electric (upper) portion. You will find it easier to remove the assembly as a whole and work on it on a table. Your auto parts store won't/can't sell you the whole assembly, just where the pulse signal is generated, the lower portion of the assembly is mechanical.

 

If similar to my 4th gens, the lower portion (with two hoses) is the power steering speed sensor, it is used to vary the power steering assist with speed. The upper electrical portion provides a pulsing signal used to operate the speedometer, odometer, and cruise control.