Troubleshooting Speedometer/odometer
 

I've seen many threads on this issue but I am not sure where my symptoms are pointing.
1994 FWD stock SVX L. This was my daily driver until trans went (FWD). It sat for a year or so.
Speedometer also died just before the trans went. Not sure if odometer and trip odo died with it (at that time, I assume so). Finally replaced transmission. Observing the speedometer/odo/trip with a GPS over the last few weeks it has been working intermittenly...Went from not working at all, everything dead, to recording mileage at approximately 66% of actual miles driven with speedo recording within 2-3 mph of GPS, then sometimes speed jumps 0-20 etc, you've heard it before. Got my emissions notice so I jumped in one morning, cranked it up and everything is working fine, perfect, speedo/odo/trip. Failed emissions, gas cap. ok new cap. passed emissions.
So, after having the cluster work perfect several mornings, seems like everything dies in about an hour, give or take, not real sure of the time. It stopped working completely again, finally I assumed, so replaced gauge cluster (which was unbelievably within 500 miles of the original mileage)
but speedo is still dead, and odometer recorded 3 tenths of a mile on a 1.7 mile distance as measured by another car. I reseated the VSS connector. No change. Did not replace the VSS. I see them online @ $100+ to maybe $250. Is the VSS the problem? While looking at the back of my original cluster, I noticed the screws on the speedo could be tightened a little which I did but not more than a quarter turn (in other words, they seemed ok). I did not check any screws on the back of the replacement cluster that is currently in the car. Current status: no speedometer and mileage recording way too low. Is the VSS the problem?

Re: Troubleshooting Speedometer/odometer
 

Paul, this is the VSS2 failing on the differential. Originally I suspected the cluster as it had seemed it was only the speedometer that was reading incorrectly based on your descriptions and observations.

Re: Troubleshooting Speedometer/odometer
 

Hopefully it's not the speedo drive gear, that's worst case scenario. It could be hardened grease in the VSS. You could try to remove, degrease and re-lube your VSS. This worked for me. Intermittent problems usually tend to not be the drive/driven gear.

Re: Troubleshooting Speedometer/odometer
 

I did the "power light diagnosis" but all looks normal from that. I just get the 1/4 second blink. To confirm: vss2 is just in front of the differential dipstick. Is that correct or incorrect?

Re: Troubleshooting Speedometer/odometer
 

that is correct

Re: Troubleshooting Speedometer/odometer
 

I can also confirm that. Be careful taking it out, sometimes the little spinning shaft part of it and a washer type thingy won't come out with the rest of the sensor, and will stay in the diff, but you can get it out with a magnet. Especially if the little shaft is broken.

Re: Troubleshooting Speedometer/odometer
 

Tried to do this again. How can you execute #5 with the ignition off? (#4) :confused:

1) Warm up engine by driving at speeds greater than 12mph.
2) Stop vehicle and turn ignition switch OFF.
3) Turn ignition switch ON and make sure POWER indicator lamp comes on.
4) Turn ignition switch OFF.
5) Move selector lever to D and turn manual switch ON.
6) Turn ignition switch ON.
7) Move selector lever to "3" and turn manual switch OFF.
8) Move selector level to "2" and turn manual switch ON.
9) Move selector lever to "1" and turn manual switch OFF.
10) Partially depress accelerator pedal (to turn idle switch off).
11) Check code as displayed on POWER light. Blinking once every 1/4sec is normal

Re: Troubleshooting Speedometer/odometer
 

There are 4 key positions:
1 the one where you can put it in and take it out.
2 the first switch which just turns on the radio and a few other things.
3 the second switch powers up the ECU, TCU and everything else.
4 cranking, which it springs back from. This doesn't turn on anything that wasn't turned on in 3, just also runs the starter motor.

In the above instructions, "ignition switch" refers to position 3. Not 2. With it in position 2, I think it will let you move the shifter as long as the brake pedal is down. So you should be switching it between positions 2 and 3, not 1 and 2 or 3.

Re: Troubleshooting Speedometer/odometer
 

Use the shift lock button. Not sure which models don't have one.