Diagnostic Circuit Check - Minimum Function System

Fig. 010 - Procedure for Diagnostic Circuit Check VIN C:

1982-87 VIN C (1.6L)

DIAGNOSTIC CIRCUIT CHECK

The purpose of the Diagnostic Circuit Check is to:
a. Make sure the "CHECK ENGINE" lamp is working.
b. The ECM is operating and can recognize a fault.
This is the starting point for any diagnosis.
If there are no trouble codes indicated, go to the System Performance Check.
If no additional checks are called out from the System Performance Check, go to Diagnosis by Symptom.

Fig. 009 - Chart - Diagnostic Circuit Check:

1. This checks the "CHECK ENGINE" lamp circuit. Normal operation is when "CHECK ENGINE" lamp is "on" steady.
2. This checks to see if the ECM can recognize a fault. Because the engine is not running, then there is no reference pulse and light should flash trouble code 12.
3. This checks to see if there is a problem that will set a code at curb idle for one minute.