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P0AC2




DTC P0AC0, P0AC1, P0AC2, or P1A07

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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.

P0AC2

The drive motor generator battery control module detects that the current sensor high range is less than -200 A and the current sensor medium range is less than -52 A and the current sensor low range is greater than -22 A for 3 seconds.

P1A07

The drive motor generator battery control module detects less than 4.8 V or greater than 5.2 V on the 5 V reference circuit.

Action Taken When the DTC Sets

* DTC P0AC0, P0AC1, P0AC2, and P1A07 are type A DTCs.
* The driver information center (DIC) displays the SERVICE HYBRID SYSTEM message.
* State of charge goes to invalid.
* The drive motor generator battery control module sends a message to the hybrid powertrain control module requesting that the hybrid battery power limit be set to 3 kilowatts, resulting in minimal hybrid function.

Conditions for Clearing the DTC

DTC P0AC0, P0AC1, P0AC2, and P1A07 are type A DTCs.

Reference Information
Schematic Reference

Hybrid Energy Storage Schematics [1][2]Electrical Diagrams
Connector End View Reference

Component Connector End Views Connector Views
Description and Operation

Drive Motor Battery System Description Drive Motor Battery System Description
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information
DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Special Tools

EL-48900 HEV Safety Kit

Circuit/System Verification

Ignition ON, observe the scan tool Calc. Hybrid Batt. Current parameter. The reading should be between -200 and +200 A, and change with the amount of current draw on the drive motor generator battery.

Circuit/System Testing

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.


The High Voltage Disabling procedure will perform the following tasks:


* Identify how to disable high voltage.

* Identify how to test for the presence of high voltage.

* Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.


Failure to follow the procedures exactly as written may result in serious injury or death.


1. Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling High Voltage Disabling.
2. Disconnect the harness connector at the current sensor.
3. Ignition OFF and scan tool disconnected for 30 seconds, test for less than 5 ohm between the low reference circuit terminal 2 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the drive motor generator battery control module.

4. Connect the 12 V battery.
5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.

• If less than the specified range, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the drive motor generator battery control module.
• If greater than the specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the drive motor generator battery control module.

6. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 2. Verify the scan tool Calc. Hybrid Batt. Current is greater than +225 A.

• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the drive motor generator battery control module.

7. If all circuits test normal, replace the current sensor.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Drive Motor Battery Current Sensor Replacement Drive Motor Battery Current Sensor Replacement
* Drive Motor Battery Sensor Module Wiring Harness Replacement Drive Motor Battery Sensor Module Wiring Harness Replacement
* Control Module References Control Module References for drive motor generator battery control module replacement, setup and programming

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