Displaying & Reading Trouble Codes

DESCRIPTION




1. A self-diagnosis function is built into the electrical control system. Warning is indicated by the overdrive OFF indicator.

HINT: Warning and diagnostic codes can be read only when the overdrive switch is ON. If OFF, the overdrive OFF indicator is lit continuously and will not blink.




a. If a malfunction occurs within the speed sensors or solenoids, the overdrive OFF light will blink to warn the driver.
However, there will be no warning of a malfunction with lock-up solenoid.

b. The diagnostic code can be read by the number of blinks of the overdrive OFF indicator when terminals T(T) and E(1) are short-circuited.
c. The throttle position sensor or brake signal are not indicated, but inspection can be made by checking the voltage at terminal T(T) of the check connector.
d. The signals to each gear can be checked by measuring the voltage at terminal T(T) of the check connector while driving.




2. The diagnostic (malfunction) code is retained in memory by the ECU and due to back-up voltage, is not canceled out when the engine is turned off. Consequently, after repair, it is necessary to turn the ignition switch off and remove the fuse EFI (15A) or disconnect the ENGINE and ECT ECU connector to cancel out the diagnostic (malfunction) code.

HINT:
- Low battery voltage will cause faulty operation of the diagnosis system. Therefore, always check the battery first.
- Use a voltmeter and ohmmeter that have an impedance of at least 10 kohm/V.

CHECK O/D OFF INDICATOR LIGHT




1. Turn the ignition switch ON.
2. The O/D OFF light will come on when the O/D switch is placed at OFF.
3. When the O/D switch is set to ON, the O/D OFF light should go out.
If the O/D OFF Light flashes when the O/D switch is set to ON, the electronic control system is faulty.

READ DIAGNOSTIC CODE




1. TURN IGNITION SWITCH AND O/D SWITCH TO ON
Do not start the engine.

HINT: Warning and diagnostic codes can be read only when the overdrive switch is ON. If OFF, the overdrive OFF light will light continuously and will not blink.




2. SHORT T(T) TERMINAL CIRCUIT OF CHECK CONNECTOR
Using SST, short terminals T(T) and E(1) of the check connector.
SST 09843-18020




3. READ DIAGNOSTIC CODE
Read the diagnostic code as indicated by the number of times the O/D OFF indicator flashes.

(Diagnostic Code Indication)




- If the system is operating normally, the light will blink once every 0.25 seconds.




- In the event of a malfunction, the light will blink once every 0.5 seconds. The number of blinks will equal the first number and, after 1.5 seconds pause, the second number of the two digit diagnostic code. If there are two or more codes, there will be a 2.5 seconds pause between each.

HINT: In the event of several trouble codes occurring simultaneously, indication will begin from the smaller value and continue to the larger.

4. REMOVE SST
SST 09843 - 18020