Chart C-4K EST Performance Check
Chart C-4K:
EST System Wiring Diagram:
CHART C-4K
EST PERFORMANCE CHECK
Test Description: Numbers below refer to circled numbers on the diagnostic chart.
1. Grounding "test" terminal causes the system to go to a fixed spark advance which should be different from that obtained with EST operating. Engine is run at fast idle to get more spark advance. Usually the change is enough so it can be heard in rpm change. If so, it is not necessary to check timing.
2. The check is made in drive because some engines will not have EST operating in park or neutral.
3. Checks to see if fault is in pressure sensor system.
**EMI