Description
The mil (malfunction indicator lamp) is used to indicate vehicle malfunction detections by the ecm.
When the ignition switch is turned on, power is supplied to the mil circuit, and the ecm provides the circuit ground which illuminates the mil.
The mil operation can be checked visually: when the ignition switch is first turned on, the mil should be illuminated and should then turn off. If the mil remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the intelligent tester.
Wiring diagram

Inspection procedure

Standard: mil should go off.

Ok: mil is not illuminated.

Standard resistance (check for short)



Ok: mil should be illuminated.


Hint:
*: The intelligent tester cannot communicate with the ecm.


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Fuel pump control circuit
Mass air flow meterPressure control solenoid "B" performance (shift solenoid valve sl2)
Description
The ecm uses signals from the output shaft speed sensor and input speed
sensor to detect the actual
gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect mechanical
problems of the shift solenoid ...
Terminals of ecu
Check instrument panel junction block (main body ecu)
Disconnect the ib and ie junction block connectors.
Measure the voltage and resistance of the wire
harness side connectors.
Reconnect the ib and ie junction block connector.
Measure the voltage of the wire harness ...
Brake switch "B" circuit high
Description
The purpose of this circuit is to prevent the engine from stalling while
driving in the lock-up condition when
the brakes are suddenly applied.
When the brake pedal is depressed, this switch sends a signal to the ecm. Then
the ecm cancels the
operation of the lock-up clutch ...