Without Scan Tool

DIAGNOSIS SYSTEM - GENERAL DESCRIPTION





(a) A self-diagnosis function is built into the electronic control system. Warning is indicated by the O/D OFF indicator light.

HINT:
- Warning and diagnostic trouble codes can be read only when the O/D main switch is ON. If OFF, the OlD OFF indicator light is lit continuously and will not blink.
- If a malfunction occurs within the vehicle speed sensors (No.1 or 2) or shift solenoid valves (No.1 or 2), the O/D OFF indicator light will blink to warn the driver. However, there will be no warning of a malfunction with shift solenoid valve SL.





- The diagnostic trouble code can be read by the number of blinks of the O/D OFF indicator light when terminals TE1 and E1 are connected with SST.





- The throttle position sensor or brake signal are not indicated, but inspection can be made by checking the voltage at terminal TT of the DLC 1.

- The signals to each gear can be checked measuring the voltage at terminal of the DLC1 while driving.





(b) The diagnostic trouble code is retained in memory by the ECM 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 ECM connector to cancel out the diagnostic trouble code.

HINT:
- Low battery positive 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 kOlV.