2010 Cadillac Truck Escalade RWD V8-6.2L Page 1550
DTC P0AC0, P0AC1, P0AC2, or P1A07
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0AC0
- Hybrid Battery Current Sensor Performance
DTC P0AC1
- Hybrid Battery Current Sensor Circuit Low Voltage
DTC P0AC2
- Hybrid Battery Current Sensor Circuit High Voltage
DTC P1A07
- Battery Energy Control Module 5-Volt Reference Circuit
Diagnostic Fault Information
Circuit/System Description
The hybrid battery current sensor is mounted inside the drive motor generator battery assembly. The positive high voltage cable that goes to the
positive contactor relay passes through the current sensor. The current sensor detects the amperage that flows in and out of the hybrid batteries. The
drive motor generator battery control module supplies and monitors a 5 V reference signal to the current sensor. The current sensor returns a signal
between 0 and 5 V to the drive motor generator battery control module. The current sensor signal is in proportion to the amperage going in and out
of the drive motor generator battery. A signal voltage of the current sensor greater than 2.5 V indicates that the drive motor generator battery is
being discharged and a signal voltage less than 2.5 V indicates charging. The hybrid battery current sensor has 3 measurement ranges in order to
maintain accuracy. The ranges are low, medium and high. The measurement ranges of the current sensor have some overlap with each other. The
low range measures from -22 to +22 A. The medium range measures from -52 to +52 A. The high range measures from -250 to +250 A.
Conditions for Running the DTC
* The ignition is ON.
* The 12 V battery is 9-18 V.
Conditions for Setting the DTC
P0AC0
One of the following conditions exists:
* The drive motor generator battery control module detects greater than 5 A on the current sensor after a successful high voltage system power
down and after the contactors have opened.
* The drive motor generator battery control module detects an increase in total pack voltage greater than 10 V and the current sensor measures
less than a 0.5 A increase.
* The drive motor generator battery control module detects less than 20 A on the high range sensor and the difference between the high range
current measurement and the medium range current measurement is greater than 20 A for 3 seconds.
* The drive motor generator battery control module detects less than 20 A on the high range sensor and the difference between the high range
current measurement and the low range current measurement is greater than 4 A for 3 seconds.
P0AC1
The drive motor generator battery control module detects that the current sensor high range is greater than +200 A and the current sensor medium
range is greater than +52 A and the current sensor low range is greater than +22 A for 3 seconds.
