Speedometer Not Working And O/d Off Light Flashing On And Off

[safira1971]

i have a hilux surf 1995 the o/d off light keeps flashing on and off and speedometer is not working afetr a diagnostic check n replaced speedometer sensor and speed sensor but it hasnt solved the problem please can anyone tell me what else this could be .

[Richard KM]

If you have replaced the speedometer sensor, then it's probably the speedometer. From memory, the speed sensor in the trans earths the 5v signal from the speedometer, which the speedometer then sends to the engine/trans ECU. No direct lick from ECU to speed sensor in the trans. From memory, the capacitors in the speedometer leak onto the circuit board, eating away at the circuit board tracks. If you can get the speedometer cluster out, then the speedometer out of the cluster, you will probably find some brown patches on the green circuit board tracks. If it does, it either needs to be cleaned up and the capacitors replaced, or the speedometer gauge/cluster replaced.

Not the easiest to remove the cluster on the surf, have to remove the glovebox and under the steering wheel part of the dash before you can get to removing the cluster, but that's probably the most likely suspect. Unless of course the speed sensor in the trans isn't getting spun by the trans, something wrong with the gear, although you can normally see that fairly easily when you look at it while replacing it.