Engine ECU

[Chunga]

So I just left my surf back over with the local auto spark today to have a look at the broken speedo. I gave him a wiringing diagram I found (which I think is correct) . From the diagram it looks like the speed sensor is running to the ECU and he thinks that this might be where the problem lies.

Can anyone advise please?

If it is the ECU, is there a difference between manual and automatic?

I drive a 1992 2.4 manual.

Many thanks

[BUSHWHACKER]

Auto and manual ECU are different.

The three wire sensor (black plug) on the driver's side of the transfercase controls the speedo.
http://www.roughtrax4x4.com/?doc=16&cid=148&vid=1463
You can check for a signal at the 12 pin plug on the ECU to check that it's working, green wire with a blue stripe.

There is also a speed output from the ECU that controls the fuelling. If the truck is running OK then it won't be that.

[Chunga]

Yea, I got a new speed sensor (well second hand from ebay) and tried it and still nothing. Tried a new set of clocks and the new sensor... Still nothing... Tried new sensor and old clocks and nothing. Tried new clocks with old sensor and still nothing. Every combination :P

So the auto spark was going to pin it out and check wiring, but when he looked at the diagram he said it looked like the speed sensor was running to the ECU and that is maybe what the problem is...

Any other help would be really appreciated.

Cheers

[BUSHWHACKER]

Are you sure the replacement sensor is working?

Apply 12v to pin 1
Earth to pin 2
pin 3 is the output.

If you connect a digital multi meter to pins 2 and three, turn the plastic cog and the voltage reading should fluctuate.

[Chunga]

Thanks very much for that info bushwhacker. I passed it on to the spark and he phoned me back and told me that he was getting continuity ok, but when he turned the wheel inside the unit, it was not pulsing (the signal did not vary). So the unit I got from ebay is not actually working.

He is going to test the old unit on Monday, so hopefully can get to the bottom of it.

Thanks again for all the help.