Firebird V8-305 5.0L (1982)
Engine Control Module: All Technical Service Bulletins
ECM - Revised Replacement Procedure
Number 87-6(Gasoline)-40 Date 5/87
Subject:
REVISED ECM REPLACEMENT PROCEDURE - CHART C-1
1982-87 ECM EQUIPPED VEHICLES
The purpose of this bulletin is to introduce new ECM test procedures to reduce the possibility of multiple ECM failures on any one vehicle..
Since 1982, most ECM's have used an integrated circuit (IC) in place of separate transistors to turn "ON" or "OFF" different components controlled by
the ECM. These IC's are called quad drivers (QDR). Each QDR has four separate outputs, meaning it can turn "ON" or "OFF" four different items
independently.
A failed QDR usually results in an ECM output becoming either shorted to ground or open. Many times all four QDR outputs will be inoperative if just
one vehicle circuit is faulty.
The revised diagnostic incorporates new test procedures designed to identify a damaged QDR. Once identified, the circuit must be repaired to reduce the
incidence of repeat ECM failures.
This chart replaces the current service manual procedure for either:
