Diagnostic Aids
If circuit No. 496 is not open or shorted to ground and the voltage reading is less than 4 volts, the most likely cause is an open circuit inside the ECM. If a replacement ECM did not repair the problem, it is possible a faulty MEM-CAL is drawing the voltage down and should be replaced. Check for proper installation of MEM-CAL or shorts or opens in circuit No. 496. Also, see INTERMITTENTS in TESTS W/O CODES article.