Engine Temperature Corrections

To improve cold driveability, the ECU advances spark angle. The ECU considers intake air volume and the status of the IDL contact to determine how much cold advance to add to the basic spark calculation.



Coolant Temperature (°F)

As the engine temperature approaches overtemp, the ECU will advance spark when the IDL contact is on, to prevent overheating. When the IDL contact is off, the ECU will retard spark to prevent detonation. Advance and retard shown on the graph are corrections to the basic advance angle.

Corrective Ignition Advance Angle

• Coolant Temperature

• RPM Stabilization

• Detonation

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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