Circuit Description
WARNING: This page is about a different car, the 2000 Pontiac Firebird, 2000 Chevrolet Corvette, and 2000 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
A/C clutch relay control circuit is controlled by an internal switch (driver) inside PCM. Driver incorporates a fault line that is monitored by PCM. When PCM commands relay on, voltage on control circuit is low (near zero volts). With relay commanded off, control circuit voltage reaches near battery voltage. If fault detection circuit senses a voltage other than what the expected voltage should be, DTC will set.
For duplication of DTC, ensure engine speed is greater than 400 RPM and ignition voltage is 6-18 volts.