B1972
CIRCUIT DESCRIPTIONThe Systems under controlled power are supplied voltage through the controlled power relay. The CONTROLLED POWER Relay Coil Control circuit is grounded whenever the body control module (BCM) is awake, and for 15 minutes after the ignition switch is turned to the LOCK position. After 15 minutes elapse, the battery positive voltage output circuit turns ON. The battery positive voltage output can supply up to 2 amps for up to 3 days. If the BCM detects that more than 2 amps are needed, the BCM wakes up and grounds the CONTROLLED POWER Relay Coil Control circuit.
The BCM measures the voltage at the battery positive voltage output every 300 ms while the BCM is in low power mode.
CONDITIONS FOR SETTING THE DTC
The battery positive voltage output circuit is grounded after 2 consecutive monitoring cycles.
ACTION TAKEN WHEN THE DTC SETS
The BCM turns the CONTROLLED POWER Relay Coil Control circuit OFF until the state of the ignition changes or the BCM wakes up.
CONDITIONS FOR CLEARING THE DTC
^ A current DTC clears when the malfunction is no longer present.
^ A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.
TEST
