2010 Cadillac Truck Escalade RWD V8-6.2L Page 1463
Circuit/System Description
The drive motor generator battery has four hybrid battery temperature sensors. The hybrid battery temperature sensors are located on the top of the
hybrid batteries. The temperature sensor is a variable resistor that measures the temperature of the hybrid batteries. The drive motor generator
battery control module (BECM) supplies 5 V to the signal circuit and a ground for the low reference circuit. The hybrid battery temperature sensor
resistance changes with battery temperature. The lower the temperature, the higher the resistance of the sensor. The higher the temperature, the
lower the resistance of the sensor. The drive motor generator battery control module uses the battery temperature sensors to control the battery
cooling fan operation.
The hybrid powertrain control module monitors the average battery pack temperature over serial data. When the average drive motor generator
battery temperature exceeds the calibrated temperature the hybrid powertrain control module will set DTC P0A7E and send a command to the drive
motor generator battery control module to open the high voltage contactors.
Conditions for Running the DTC
* DTC P0A9C, P0A9D, P0A9E, P0AC6, P0AC7, P0AC8, P0ACB, P0ACC, P0ACD, P0AE9, P0AEA, or P0AEB is not set.
* The ignition is ON.
* The 12 V battery voltage is 9-18 V.
Conditions for Setting the DTC
P0A7E
The hybrid powertrain control module detects an average battery temperature greater than 73掳C (163.4掳F) for 5 seconds.
P1ABE
One of the following conditions exists:
* The drive motor generator battery control module detects an average battery temperature increase of 2掳C (35.6掳F) in a 20 second event for 3
consecutive events totaling 60 seconds.
* The drive motor generator battery control module detects 2 battery temperature sensors greater than 65掳C (149掳F) for 5 seconds.
* The drive motor generator battery control module detects any battery temperature sensor greater than 70掳C (158掳F).
Action Taken When the DTC Sets
P0A7E
* DTC P0A7E is a type C DTC.
* The hybrid powertrain control module commands the drive motor generator battery control module to open the high voltage contactors relays
when the vehicle speed is below 5 km/h (3 mph).
P1ABE
* DTC P1ABE is a type C DTC.
* The drive motor generator battery control module sends a message to the hybrid powertrain control module requesting the high voltage
contactors open. The hybrid powertrain control module will command the contactors relays open when the vehicle speed is less than 5 km/h
(3 mph).
Conditions for Clearing the DTC
DTCs P0A7E and P1ABE are type C DTCs.
Diagnostic Aids
* Battery temperatures can be affected by vehicle load, outside temperature and customer driving conditions. Test drive the vehicle, and
attempt to simulate the Freeze Frame/Failure Record conditions this DTC set under.
* Inspect for the following:
- Air inlet and outlet for blockage.
- Loose or poor connections at the drive motor generator battery control module temperature sensor module X3 harness connector.
- Damage to the drive motor generator battery control module temperature sensor module wiring harness.
- Damage to the fan or blades.
