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P1A27



DTC P1A27

CIRCUIT DESCRIPTION
The following DTCs are for the battery temperature sensors located in the energy storage box (ESB) on each battery:
- P1A22 is for the hybrid battery 1 circuit low voltage.
- P1A23 is for the hybrid battery 1 circuit high voltage.
- P1A26 is for the hybrid battery 1 voltage low.
- P1A27 is for the hybrid battery 1 voltage very low.
- P1A28 is for the hybrid battery 1 voltage high.
- P1A29 is for the hybrid battery 2 circuit low voltage.
- P1A2A is for the hybrid battery 2 circuit high voltage.
- P1A2D is for the hybrid battery 2 voltage low.
- P1A2E is for the hybrid battery 2 voltage very low.
- P1A2F is for the hybrid battery 2 voltage high.
- P1A30 is for the hybrid battery 3 circuit low voltage.
- P1A31 is for the hybrid battery 3 circuit high voltage.
- P1A34 is for the hybrid battery 3 voltage low.
- P1A35 is for the hybrid battery 3 voltage very low.
- P1A36 is for the hybrid battery 3 voltage high.




Battery voltage sensors allow the energy storage control module (ESCM) to monitor the voltage of the batteries in the energy storage box. The batteries apply voltage to internal input resistors that are connected to the signal circuits of the battery voltage sensors. The module provides ground to the battery temperature sensors through the reference circuit. The ESCM monitors the voltage drop across the battery voltage sensors and uses the inputs for hybrid calculations. When the battery voltage is high, the resistances of the sensors are high and the voltage signals are high. When the battery voltage is low, the resistances of the sensors are low and the voltage signals are low.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC P1A22 Hybrid Battery 1 Circuit Low Voltage
- DTC P1A23 Hybrid Battery 1 Circuit High Voltage
- DTC P1A26 Hybrid Battery 1 Voltage Low
- DTC P1A27 Hybrid Battery 1 Voltage Very Low
- DTC P1A28 Hybrid Battery 1 Voltage High
- DTC P1A29 Hybrid Battery 2 Circuit Low Voltage
- DTC P1A2A Hybrid Battery 2 Circuit High Voltage
- DTC P1A2D Hybrid Battery 2 Voltage Low
- DTC P1A2E Hybrid Battery 2 Voltage Very Low
- DTC P1A2F Hybrid Battery 2 Voltage High
- DTC P1A30 Hybrid Battery 3 Circuit Low Voltage
- DTC P1A31 Hybrid Battery 3 Circuit High Voltage
- DTC P1A34 Hybrid Battery 3 Voltage Low
- DTC P1A35 Hybrid Battery 3 Voltage Very Low
- DTC P1A36 Hybrid Battery 3 Voltage High

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- The engine has been running for 30 seconds.

CONDITIONS FOR SETTING THE DTC
- P1A22 battery 1 voltage as read by the ESCM is below 2 volts.
- P1A23 battery 1 voltage as read by the ESCM is above 18 volts.
- P1A26 battery 1 voltage as read by the ESCM is below a calibrated value.
- P1A27 battery 1 voltage as read by the ESCM is below a calibrated value.
- P1A28 battery 1 voltage as read by the ESCM is above a calibrated value.
- P1A29 battery 2 voltage as read by the ESCM is below 2 volts.
- P1A2A battery 2 voltage as read by the ESCM is above 18 volts.
- P1A2D battery 2 voltage as read by the ESCM is below a calibrated value.
- P1A2E battery 2 voltage as read by the ESCM is below a calibrated value.
- P1A2F battery 2 voltage as read by the ESCM is above a calibrated value.
- P1A30 battery 3 voltage as read by the ESCM is below 2 volts.
- P1A31 battery 3 voltage as read by the ESCM is above 18 volts.
- P1A34 battery 3 voltage as read by the ESCM is below a calibrated value.
- P1A35 battery 3 voltage as read by the ESCM is below a calibrated value.
- P1A36 battery 3 voltage as read by the ESCM is above a calibrated value.

ACTION TAKEN WHEN THE DTC SETS
- The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE DTC
- The DTC will become history if the ESCM no longer detects a fault.
- The history DTC will clear after 40 fault-free ignition cycles.
- The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-10:




Steps 11-14:




The numbers below refer to the step numbers on the diagnostic table.
3. Verifies that the temperature displayed is not within the calibrated range.
4. Tests for the proper operation of the circuit in the high voltage range.
5. Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
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