A self-diagnosis checker (such as 49-H018-9A1) is used to retrieve code numbers
of malfunctions which have happened and were memorized or are continuing. The
malfunction is indicated by a code number.
If there is more than one malfunction, the code numbers will display on the
self-diagnosis checker one by one in numerical order. In the case of malfunctions,
09, 19, 01, the code numbers are displayed in order of 01, 09 and then 13.
The memory of malfunctions is canceled by disconnecting the negative battery
cable.
The ECU had a fail-safe mechanism for the main input sensors. If a malfunction
occurs, the emission control unit will substitute values. This will slightly
affect the driving performance, but the vehicle may still be driven.
The ECU continuously checks for malfunctions of the input devices during operation.
But, the ECU checks for malfunctions of the output devices within three seconds
after turning the ignition switch to the ON position and the test connector
is grounded.
The malfunction indicator light (MIL) indicates a pattern the same as a self-diagnosis
checker when the self-diagnosis check connector is grounded. When the self-diagnosis
check connector is not grounded, the lamp illuminates steady while malfunction
of the main input sensor occurs and goes out if the malfunction recovers. However
the malfunction code is memorized in the emission control unit.
- Connect the Self-Diagnosis Checker to the check connector. The check connector
is usually located above the right side wheel housing.
- Set the selector switch on the tester to the A position.
- Ground the green test connector using a suitable jumper wire.
- Turn the ignition switch to the ON position. Check that number "88'' flashes
on the digital display and the buzzer sounds for three seconds after turning
the ignition switch ON.
- If the number "88'' does not flash, check the main power relay, power supply
circuit and check the connector wiring.
- If the number "88'' flashes and the buzzer sounds continuously for more
than 20 seconds, replace the ECU and perform steps 3 and 4 again.
- Note the code numbers and check the causes. Repair as necessary. Be sure
to recheck for code numbers after repairing.
- During the self-test a service code is reported by the malfunction indicator
light. It will represent itself as a flash on the CHECK ENGINE or SERVICE
ENGINE SOON light on the dash panel. A single digit number of 3 will be reported
by 3 flashes. However, if a service code is represented by a 3-digit number
such as 111, the code will appear on the MIL light as three flashes, then
after a two second pause, the light will flash three times.
- Start the engine and allow it to reach normal operating temperatures.
- Turn the engine off. Connect a jumper wire from the STI to the SIG RTN at
the self test connectors and then turn the ignition switch to the ON position.
Service codes will be flashed on the MIL light.
