Circuit Description

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The following DTC is for the batteries located in the energy storage box (ESB):

P0A7E is for the hybrid battery pack overtemperature.

Battery temperature sensors allow the energy storage control module (ESCM) to monitor the temperature of the batteries in the energy storage box. The module applies 5 volts to internal input resistors that are connected to the signal circuits of the battery temperature sensors. The module provides ground to the battery temperature sensors through the low reference circuit. The ESCM monitors the voltage drops across the battery temperature sensors and uses the inputs for hybrid calculations. When the battery temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the battery temperatures are hot, the resistances of the sensors are low and the voltage signals are low.