Toyota Celica/Supra 1971-1985 Repair Guide

Reading Codes


To obtain the diagnostic codes the following conditions must be met.

Battery voltage above 11 volts.
Throttle valve fully closed (throttle position sensor points closed)
Transmission in neutral position
Accessory switches OFF
Engine at normal operating temperature

  1. Turn the ignition switch to the ON position. Do not start the engine.
  3. Using a wire, short the terminals T-E1 of the check engine connector.
  5. Read the diagnostic code as indicated by the number of flashes of the Check Engine light.
  7. The normal operation code No. 1. the light will blink once every 4 1 / 2 seconds.
  9. If there is a malfunction in the system, the light will blink a number of times equal to the malfunction code indicated every 4 1 / 2 seconds. The code series will repeat as long as the check connector terminals (T-E1) are shorted.
  11. After the diagnosis check, remove the sub-wire and install the rubber cap to the check engine connector.