Hi all, I need some guidance here on a problem.

Recently my speedometer quit working. Cruise control stopped, Overdrive Light Blinking, ABS Light On, Service Engine Light On and the transmission started acting messed up. Odometer worked. Did a quick search and seen where the rear ABS sensor was probably the cause.

Upon inspection I found a squirrel had chewed through the speed sensor wiring right at the plug to the ABS Speed Sensor on top of the rear differential. I had already purchased a new sensor so I installed it. I went to a nearby junk yard and got a plug and wiring. Spliced in the new plug. Tested the voltage with the key on and was getting around 3.5 Volts. So I reset the cluster and all gages would sweep. I started it up and the ABS & Service engine soon lights disappeared. I took a little test drive but the transmission still not wanting to shift to 2nd without some help. When the transmission hit 2nd gear it shifted hard and the odometer goes to all ------- dashes across it. Speedometer never worked.

Does anyone know what else I can check? I would think if it were a wiring problem I wouldn't be seeing the voltage at the rear sensor. When I replaced the sensor there was minimal amount of metal shavings. Could the squirrel have shorted the wiring to the PCM or PSOM when it chewed through. How can I test these? I really can't afford right now to take it somewhere. When I was having the problem initially I went to Advanced Auto and the only codes were for the rear ABS Sensor.

 

I'm guessing that Mr. Squirrel dined at more than one location. Check the wiring that is on the tranny.

 

You are correct! He also ate the return fuel line which has been repaired. I've searched all over for other wiring that he might have had on the menu but not finding anything. Thanks!

 

Well, after replacing the ABS rear sensor on the differential all of the scan codes disappeared but still no fix. Only the ABS light and SES light shut off. However I began getting another code p0720 for the Output Speed Shaft Sensor. I checked the wiring and it all appeared ok. I know on several forums everyone says that this sensor has nothing to do with the speedometer not working. This is wrong information. I changed the Output sensor and everything is working great now. It must also supply information to the PCM to help determine speed. Anyway after chasing this for a couple weeks problem solved.

Side note: Be sure when replacing the sensors that the area they mount to is clean! Also, when I replaced the ABS rear sensor I had to take a piece of emery cloth and sand a little rust ring just above where the old o-ring was seated in the hole on the differential. After putting oil on the new O-ring it slid right in and even made a little popping sound when going down in the hole.