Is QCSC DAS ideal for educators? YES

87 Olds Calais/FWD/ 3.0L vin L/Distributorless /MFI non-sequential/4 wire crank sensor with ESC.

Readings taken at the ignition module and the ESC module. This snapshot was taken while cranking/starting.

Ch0 is the reference pulse going up to the ECM. Notice that it is 0 volts low and 10 volts when high. The ECM needs this signal to know when to pulse the injectors.

Ch1 is the EST signal as measured at the ignition module pin 'A'. Notice that it is initially grounded. When we see the EST signal rise, we know that the ECM has put 5v on the Bypass line and the engine has started. Typically the EST square wa ve signal is 0v when low and 4.2v when high. The EST signal will read about 2v on a DVOM while the engine is running. Usually the EST voltage will vary slightly if you blip the engine.

Ch2 is the knock sensor as measured at pin 'E' (dk/blu) of the ESC module. It is normal to get a small amount of knock while cranking. Usually this line (knock sensor, ckt 496) will read about 0 volts. When the knock sensor detects a knock, it generates a low voltage-high frequency signal.

Ch3 is the ESC signal line as measured at the ESC module pin 'C' (ckt 457, yel). This line connects to the ECM at pin 'B7'. Normally the ESC signal line will read about 9.1 volts. When knock occurs, the ESC module removes the 9 volts from the E SC signal line, the voltage at ECM pin 'B7' drops to 0 volts, and the ECM starts retarding the EST signal. The ESC module provides the 9 volts. Code 43 will be set if the ESC signal is low for more than 2.2 seconds.

Return to top or; Previous or; Next

For more info, call: Quad Computer Systems Consultants, 973-472-0328, ASK FOR DAN

EMAIL to; qcscdas@aol.com or; danbuckley@worldnet.att.net or; lody@delphi.com
Please entitle email inquiries: QCSC DAS

QCSC DAS Copyright 1996 -- Developed by; Daniel A. Buckley (NIASE GAM-CMAT-L1)

87lbcrn