P0AFA

P310 HYBRID BATTERY CONTROL: HYBRID BATTERY SYSTEM: P0AFA-123: Hybrid Battery System Voltage Low

DTC P0AFA-123 - Hybrid Battery System Voltage Low

DESCRIPTION
The HV battery uses nickel metal-hydride batteries and does not require external charging. The hybrid vehicle control ECU controls the SOC (state of charge) of the HV battery at a constant level during driving. The HV battery is composed of 30 modules, and each module consists of eight 1.2 V cells in series. The battery smart unit monitors battery block voltage at 15 locations. Each battery block is composed of 2 modules in a set.









MONITOR DESCRIPTION

The battery smart unit monitors a voltage of the battery blocks to detect an open in internal battery voltage sensor circuits of the battery smart unit and the wire harness between each battery block and battery smart unit. If the voltage at any of the battery blocks is out of the specified range, the battery smart unit judges that there is an open in the internal sensor circuit(s) or wire harness. The hybrid vehicle control ECU then illuminates the MIL and sets a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

CASE 1:





CASE 2:





COMPONENT OPERATING RANGE





INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.
HINT: At least 5 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT (DTC P0A1F-123 IS OUTPUT)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Read output DTCs Hybrid Battery System.
Result:






B -- GO TO DTC CHART Diagnostic Trouble Code Descriptions (P0A1F-123)
A -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (BATTERY SMART UNIT CONNECTOR)
CAUTION: Be sure to wear insulated gloves and protective goggles.
(a) Remove the battery cover Components.





(b) Check the connections of the connectors shown in the illustration.
Result:






NG -- CONNECT SECURELY
OK -- Continue to next step.
3. REPLACE BATTERY SMART UNIT
(a) Replace the battery smart unit Components.
NEXT -- Continue to next step.
4. CLEAR DTC
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Clear DTCs and freeze frame data Hybrid Battery System.
NEXT -- Continue to next step.
5. RECONFIRM DTC OUTPUT
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Read output DTCs.
Result:






B -- REPLACE HV BATTERY ASSEMBLY
A -- RETURNS TO NORMAL OPERATION