speed sensor problem

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Hello fellow Supra Lovers,

The Answer is Replace the Odometer Module!! Please read on.

A couple of years ago I had this same dreaded problem with my pride and joy (93 2JZGTE 6Speed).
Symptoms were the same; Cruizing along all ok and suddenly the car felt like it was surging Master Caution Light (The Big Red Exclamation Mark) comes on and the check engine light comes on. Pulling up the car idle drops below it's ideal 600RPM to 300 and running lumpy and then stopping. Re-starting it still lumpy and then it suddenyl all goes away and seems fine.
I took my car to 3 maybe 4 supposed experts (Big Name Tuning Houses) as well as an electrician, no offence to the sparky who replied previously and they came up with 0!
After many nights studying the electrical system and talking to other Supra owners around the world it came down to Three things.
1. Change the speed sensor, 2. Change the ECU or 3. Replace the Odometer Module. Which is the Odometer and Trip meter panel.
Behind all of that lies an interrogator which receives inputs from the Transmission Speed Sensor and Interrogates it and then Translates/Refines this signal to the ECU so the Computer knows what to do! If you read the reccomendations in the Supra Manual for the error code which I think was Code42 it suggests everything except for replacing the Odometer Module and yet the module is the cheapest thing to replace at about 100 buck or less to fix this mysterious problem.
Hope this helps guys..........