Firebird V6-173 2.8L VIN L 2-bbl HP (1983)
4.
Check engine light should be "on" and a Code 43 set because ESC system would be retarded too long. If no light comes on, the ECM is not
retarding the spark because of a voltage on the circuit to terminal "L" or the ECM is faulty.
5.
Checks to see if knock sensor is reason for retard signal. If engine knock is not present, and timing increases when knock sensor is disconnected,
fault is an over sensitive knock sensor. Timing should not normally increase.
6.
Checks to see if retard signal is due to "noise" on signal wire or faulty controller. If timing increases when wire is disconnected from controller,
fault is due to knock sensor signal wire running too close to an ignition or charging system wire. Reroute wire to correct.
