- The battery voltage should be above 11 volts. Throttle valve fully closed (throttle position sensor IDL points closed).
- Place the transmission in "P" of "N" range. Turn the A/C switch OFF. Start the engine and let it run to reach its normal operating temperature.
WITHOUT SUPER MONITOR DISPLAY
- Turn the ignition switch to the ON position. Do not start the engine. Use a suitable jumper wire and short the terminals of the check engine connector. Also on the 1989-90 Cressida use a suitable jumper wire and short terminals TE2 and E1 of the Toyota Diagnostic Communication Link (TDCL) located under the left-hand side of the instrument panel. When the engine is ready to go into diagnostic output mode, short terminals TE1 and E1, this is to be done on the 1989-90 Cressida only.
- Read the diagnostic code as indicated by the number of flashes of the CHECK ENGINE warning light.
- If the system is operating normally (no malfunction), 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 first number of blinks will equal the first digit of a two digit diagnostic code. After a 1.5 second pause, the second number of blinks will equal the second number of a 2 digit diagnostic code. If there are two or more codes, there will be a 2.5 second pause between each.
In event of a number of trouble codes, indication will begin from the smaller value and continue to the larger in order.
- After the diagnosis check, remove the jumper wire from the check connector.
WITH SUPER MONITOR DISPLAY
- Turn the ignition switch to the ON position. Do not start the engine.
- Simultaneously push and hold in the SELECT and INPUT M keys for at least three seconds. The letters DIAG will appear on the screen.
- After a short pause, hold the SET key in for at least three seconds. If the system is normal (no malfunctions), ENG-OK will appear on the screen.
- If there is a malfunction, the code number representing that malfunction will appear on the screen. In the event of two or more numbers, there will be a three second pause between each (Example ENG-42).
- After confirmation of the diagnostic code, either turn OFF the ignition switch or push the super monitor display key on so the time appears.