S10/T10 P/U 2WD V6-262 4.3L VIN Z TBI (1995)
Ignition Control Module: Testing and Inspection
RESULTS OF INCORRECT IGNITION CONTROL (IC) OPERATION
The control module uses information from the Manifold Absolute Pressure (MAP) and coolant sensors in addition to RPM to calculate spark
advance as follows:
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Low MAP output voltage = More spark advance
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Cold Engine = More spark advance
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High MAP output voltage = Less spark advance
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Hot engine = Less spark advance
Detonation can be caused by low MAP output or high resistance in the coolant sensor circuit.
Poor performance can be caused by high MAP output or low resistance in the coolant sensor circuit.
IC PERFORMANCE CHECK
To check IC operation, place the vehicle in "Park" or "Neutral" and block the drive wheels. Start the engine and accelerate to 2000 RPM. Note the
ignition timing. Disconnect the "Set Timing" connector and again note the timing. The timing will change if the IC system is operating.
Diagnostic Trouble Code (DTC) PO32O
If the above conditions are met a DTC PO32O will set.
