Circuit Description

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

With the ignition ON, battery voltage is supplied to the skip shift lamp through the instrument panel cluster (IPC). The powertrain control module turns on the skip shift lamp at the same time the skip shift solenoid is enabled. The powertrain control module (PCM) controls the skip shift lamp by grounding the control circuit via an internal switch called a driver. The driver supplies the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low, near 0 volts. When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the internal fault detection circuit senses a voltage other than what is expected, the fault line status changes, causing DTC P0804 to set. DTC P0804 is a type C DTC.