P0A8F
DTC P0A8F
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 Descriptor
DTC P0A8F
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14 V Power Module System Voltage Performance
Circuit/System Description
The generator control module also called the starter generator control module is comprised of the following three control modules; the hybrid powertrain control module, 14 volt power module and the drive motor control module. These three control modules are non serviceable and are part of the generator control module.
The 14V power module has a voltage sensor that constantly monitors system output voltage. This diagnostic is designed to test the performance of the voltage sensor. This sensor is internal to the 14V power module and is not serviced separately from the generator control module.
Conditions for Running the DTC
* The ignition is ON.
* 14V Power Module Status parameter is Normal.
* Ignition voltage is between 9-16V.
Conditions for Setting the DTC
P0A8F
The difference between the Low Voltage Circuit Voltage and the ignition voltage value is greater than 4.5 volts for greater than 4 seconds.
Action Taken When the DTC Sets
* The charging system light will illuminate, and Service Battery Charging System will display on the Driver Information Center.
* DTC P0A8F is a Type B DTC.
Conditions for Clearing the DTC
DTC P0A8F is a Type B DTC.
Diagnostic Aids
This DTC may set due to low 12 V system voltage.
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics [1][2]Electrical Diagrams
Description and Operation
* Starter Generator Description and Operation Starter Generator Description and Operation
* Generator Control Module Description and Operation Generator Control Module Description and Operation
* Hybrid Modes of Operation Description Hybrid Modes of Operation Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Circuit/System Verification
1. Ignition OFF, measure and record the battery voltage at the C1 12V battery terminals. The battery voltage should stabilize between 12.4 and 12.8 V within a few minutes of turning the ignition OFF.
• If not within the specified range, refer to Battery Inspection/Test Battery Inspection/Test for Hybrid (HP6).
2. Ignition ON, observe the scan tool Ignition 1 Signal parameter in the 14V Power Module data list. The parameter should be within 4.5 volts of the Low Voltage Circuit Voltage measured at the C1 12V battery.
• If the voltage is not within the specified range, check the ignition circuit to the K59 starter generator control module for high resistance.
3. Remove the B+ terminal at the K59 starter generator control module.
4. Connect a test lamp between C1 12-volt positive battery post and the K59 starter generator control module terminal at the module.
5. Ignition ON, observe the scan tool parameter Low-Voltage Circuit Voltage in the 14V Power Module data list. The parameter should be within 0.5 volt of the actual 12-volt battery voltage.
• If the voltage is not within the specified range, replace the K59 starter generator control module.
6. Ignition OFF, remove the positive connection at the C1 12-volt battery.
7. Measure the resistance of the 14 V Power Module positive harness between the X10 connector at the K59 starter generator control module and the X50A fuse block-underhood connection.
• If the resistance is greater than 1.0 ohms, repair the high resistance condition in the 12-volt circuit.
• If the resistance is less than 1.0 ohms, replace the K59 starter generator control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
Control Module References Programming and Relearning for Generator Control Module, also called the Starter Generator Control Module, replacement, programming and setup.