Inspection of Electronic Control Components

1. INSPECT VOLTAGE OF ECM.
- Turn on the ignition switch.



- Measure the voltage at each terminal.









2. INSPECT SOLENOID.
- Disconnect the connector from ECM.

View Of ECM Connector:

- Measure the resistance between S1, S2, SL and ground.

Resistance: 11 - 15 Ohms

- Apply battery positive voltage to each terminal.
- Check that an operation noise can be heard from each solenoid.

3. CHECK SOLENOID SEALS.
- If there is foreign material in the solenoid valve, there will be no fluid control even with solenoid operation.
- Check No.1, No.2 and lock-up solenoid.



- Apply 490 kPa (71 psi) of compressed air, check that the solenoid valves do not leak air.
- Apply battery voltage to the solenoids, check that the solenoid valves open.

4. INSPECT NO.2 VEHICLE SPEED SENSOR.
- Jack up the one of the rear wheels.



- Connect an ohmmeter between the terminals.
- Spin the wheel and check that the meter needle deflects from 0.0 Ohms to infinite Ohms.

5. INSPECT NO.1 VEHICLE SPEED SENSOR.

No.1 Vehicle Speed Sensor:

- Connect the positive (+) lead from battery to terminal 2 and negative (-) lead to terminal 2.
- Connect the positive (+) lead from a voltmeter to terminal 3 and negative (-) lead to terminal 2.



- Revolve shaft.
- Check that there is voltage change from approx. 0.0 Volts to 11.0 Volts or more between terminals 2 and 3.
HINT: The voltage change should be 4 times for every revolution of the speed sensor shaft.
- If operation is not as specified, replace the sensor.

NOTE: The ECM will normally use the signal from the NO.2 vehicle speed sensor to determine shift points. However, if that sensor fails, it is programmed to switch to the No.1 vehicle speed sensor signal.

6. INSPECT THROTTLE POSITION SENSOR.
- Using an ohmmeter, check the resistance between terminals.

Throttle Position Sensor Terminal Resistance:

7. INSPECT ENGINE COOLANT TEMPERATURE SENSOR.
- Refer to Engine Coolant Temperature Sensor inspection procedures under Computers and Control Systems.


8. INSPECT O/D MAIN SWITCH.
- Using an ohmmeter, check the continuity of the terminals for each switch position.

O/D Main Switch Terminals:

9. INSPECT PARK/NEUTRAL POSITION SWITCH.
- Check that there is continuity between terminals.

Park/Neutral Position Switch Connector:

Park/Neutral Position Switch Terminal Continuity: