P0AFA

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

DTC P0AFA-123 - Hybrid Battery System Voltage Low

DESCRIPTION
- The hybrid vehicle control ECU controls the SOC (state of charge) of the HV battery at a constant level while driving. The HV battery is composed of 20 modules, and each module consists of 12 1.2 V cells in series. The battery smart unit monitors battery block voltage at 20 locations.









HINT: Values below 2.0 V may not be indicated in the data list due to the substitution of a fail-safe value.

MONITOR DESCRIPTION

The battery smart unit monitors a voltage of the battery blocks to detect an open malfunction in internal battery voltage sensor circuits of the battery smart unit and the wire harness between each battery block and battery smart unit. If a voltage at one of the battery blocks is below a standard level or of all the battery blocks is within a 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 set a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. 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 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT: Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK FOR DTCS (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) Check if DTCs are output.
Result:






B -- GO TO DTC CHART (P0A1F-123)
A -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION
CAUTION:
Be sure to wear insulated gloves.




(a) Check the connection of connector z32 of the battery smart unit.
OK:
The connector is connected securely and there are no contact problems.
HINT: For the removal and installation procedures related to the battery smart unit connector inspection, Components.

NG -- CONNECT SECURELY
OK -- Continue to next step.
3. REPLACE BATTERY SMART UNIT
HINT: For the removal and installation procedures related to the battery smart unit, Components.

NEXT -- Continue to next step.
4. CLEAR DTC (HV)
(a) Install the HV battery.
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(e) Clear the DTCs and freeze frame data.
(f) Perform a symptom simulation test.
NEXT -- Continue to next step.
5. RECONFIRM DTC OUTPUT (HV)
(a) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(b) Check if DTCs are output.
Result:






B -- REPLACE HV BATTERY
A -- COMPLETED