Steering Control Module: Testing and Inspection

Fig. 45 ECU Connector Inspection. Supra:

1. Using suitable stands, raise and support vehicle.
2. Remove glove box. Do not disconnect ECU electrical connector.
3. Start engine.
4. Using suitable voltmeter, measure voltage between terminals SOL - and GND with engine at idle, Fig. 45, .30-.46 volts on 1989 models or .32-.44 volts on 1990-92 models should be indicated.
5. Place transmission in gear and while running at 31 mph, measure voltage between terminals SOL - and GND.
6. On 1989 models, total voltage should be .13-.27 volts.
7. On 1990-92 models, total voltage should be voltage measured in step 4 plus an additional .09-.23 volts.
8. On all models, if no voltage is indicated, replace ECU.
9. Install glove box and lower vehicle.