LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 1990 >> Step Van 7.4 N, Standard >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Diagnosis - Torque Converter Clutch >> Diagnostic Charts >> Downshift Control Electrical Diagnosis - (4L60 - CCC TBI) >> Circuit Description

Circuit Description

When accelerator pedal is fully depressed, manifold vacuum drops, causing MAP sensor signal voltage to increase to about 4 volts. The ECM responds by grounding circuit No. 422 to energize downshift control relay. The downshift control relay then sends battery voltage to detent solenoid that causes a forced transmission downshift.

scientia non olet · About LEMON Manuals