Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0AFA: Hybrid Battery System Voltage Low - ACCM 300VDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
HVDC+ | P1AF0, P1AF2 | P0AFA | -- | -- |
HVDC- | P1AF0, P1AF2 | P0AFA | -- | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running. Parameter Normal Value: 300.0 V | |||
HVDC+ | 300.0 V | 300.0 V | -- |
HVDC- | 300.0 V | 300.0 V | -- |
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running. Parameter Normal Value: 300.0 V | |||
HVDC+ | 300.0 V | 12.0 V | -- |
HVDC- | 300.0 V | 12.0 V | -- |
Circuit/System Description
The air conditioner control module (ACCM) monitors the high voltage direct current (HVDC) voltage to ensure that the voltage stays within the proper range. Damage to components, and incorrect data may occur when the voltage is out of range. If the ACCM detects low HVDC voltage, then DTC P0AFA will set.
Conditions for Running the DTC
| • | The engine is running or is in autostop mode. |
| • | The 12 V battery voltage is between 9.5-18 V. |
Conditions for Setting the DTC
The ACCM detects that the hybrid battery voltage is less than 215 V for 0.5 seconds.
Action Taken When the DTC Sets
The air conditioning is disabled.
Conditions for Clearing the DTC
| • | The DTC will pass when the ACCM detects a hybrid battery voltage greater than 225 V. |
| • | A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-48900 HEV Safety Kit
Circuit/System Verification
- Verify that no hybrid powertrain control module (HPCM) or engine control module (ECM) DTCs are set that indicate generator, HPCM, or battery failure, or that disable the high voltage.
- Engine cranking, observe the scan tool accessory DC power control module (APM) HPCM 300V Circuit parameter. The reading should be between 225 V and 380 V.
- Ignition ON, observe the scan tool ACCM High Battery Voltage parameter. The reading should be between 225 V and 380 V.
| ⇒ | If the specified DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. |
| ⇒ | If not within the specified range, refer to Jump Assist. |
Circuit/System Testing
- Disable the high voltage, and remove the 3 phase cable cover.
- Verify that the ACCM 300 V fuse is not open.
- Ignition OFF, verify that the air conditioner compressor HVDC terminal bolts are present and are torqued to specification.
- If all circuits test normal, replace the ACCM.
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. |
| ⇒ | If the fuse is open, replace the fuse. If the fuse opens again, replace the ACCM. |
| ⇒ | If the bolts are missing or are not tight, replace any damaged components, install and tighten the bolts. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ACCM replacement, setup, and programming.
