P0AC2
DTC P0AC0, P0AC1, P0AC2, or P1A07
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P0AC0
- Hybrid Battery Current Sensor Performance
DTC P0AC1
- Hybrid Battery High Current Sensor Circuit Low Voltage
DTC P0AC2
- Hybrid Battery High Current Sensor Circuit High Voltage
DTC P1A07
- Battery Energy Control Module 5 Volt Reference Circuit
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The hybrid battery current sensor is mounted on the positive cable side internal to the hybrid drive motor battery assembly. The current sensor detects the amperage that flows in and out of the hybrid batteries. The current sensor outputs a voltage signal between 0 and 5 volts to the BECM. The current sensor output voltage signal is in proportion to the amperage going in and out of the drive motor generator battery. An output voltage of the sensor above 2.5 volts indicates that the batteries are being discharged and a output voltage below 2.5 volts indicates charging. The hybrid battery current sensor has 3 ranges in order to maintain accuracy. The ranges are low, medium and high.
Conditions for Running the DTC
* The vehicle power mode is RUN.
* Accessory voltage is 9-18 volts.
Conditions for Setting the DTC
The BECM detects a malfunction in the hybrid battery current sensor for after 4 seconds.
Action Taken When the DTC Sets
DTCs P0AC0, P0AC1, P0AC2, and P1A07 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0AC0, P0AC1, P0AC2, and P1A07 are Type B DTCs.
Diagnostic Aids
Wear insulated gloves while inspecting for the following conditions:
* Loose or poor connections at the BECM connector.
* Loose or poor connections at the hybrid battery current sensor connector.
Special Tools
* EL-48569 Terminal Covers
* EL-48900 HEV Safety Kit
* Voltage vs. Current Table
Circuit/System Verification
1. Ignition ON, engine running. The output voltage of the current sensor should be above 2.6 volts, indicating the batteries are being discharged, or below 2.4 volts, indicating the batteries are being charged. The output voltage of the current sensor with a low or no current flow should be between 2.4-2.6 volts.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
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.
Ignition OFF, disable the high voltage at the drive motor generator battery. Refer to High Voltage Disabling.
1. Remove the drive motor generator battery case upper cover, front cover and right side cover.
2. Ignition OFF, connect the 12 volt battery.
3. Disconnect X6 at the current sensor.
4. Ignition OFF, test for less than 2 ohms of resistance between low the reference circuit terminal 2 and ground.
^ If greater than the specified range, test the low reference circuit for a open/high resistance, If the circuit tests normal, replace the BECM.
5. Ignition ON, test for 4.9-5.1 volts between the 5 volt reference terminal 1 and ground.
^ If not within the specified range, test the 5 volt reference circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the BECM.
6. Ignition ON, test for 4.7-5.3 volts between the signal circuit terminal 3 and ground.
^ If not within the specified range, test the signal circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the BECM.
7. If all circuits test normal, replace the current sensor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair. Verification Tests
* Drive Motor Battery Current Sensor Replacement
* Drive Motor Generator Battery Control Module and Bracket Replacement