Circuit Description
The following DTCs are for the battery voltage sensors located in the energy storage box (ESB) on each battery:
| • | P1A24 is for the hybrid battery 1 voltage. |
| • | P1A2B is for the hybrid battery 2 voltage. |
| • | P1A32 is for the hybrid battery 3 voltage. |
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 voltage 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. The out of range rationality diagnostics (P1A24, P1A2B, P1A32) determine if each sensor is within a certain amount of the average of the sensors. These faults are only run when during discharge, and when the 42V bus correlation is valid and stable.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P1A24 Hybrid Battery 1 Voltage |
| • | DTC P1A2B Hybrid Battery 2 Voltage |
| • | DTC P1A32 Hybrid Battery 3 Voltage |
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The engine has been running for 30 seconds. |
Conditions for Setting the DTC
| • | P1A24 is for the hybrid battery 1 voltage correlation fault. |
| • | P1A2B is for the hybrid battery 2 voltage correlation fault. |
| • | P1A32 is for the hybrid battery 3 voltage correlation fault. |
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. |
Disconnected sensor | Expected Result Displayed on Scan Tool | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Voltage Sensor 1 |
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Voltage Sensor 2 |
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Voltage Sensor 3 |
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Voltage Sensor 4 |
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Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step verifies that the voltage displayed is not within the calibrated range.
-
This step tests for the proper operation of the circuit in the high voltage range.
-
This step 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.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Starting and Charging Schematics Connector End View Reference: Engine Electrical Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Test each battery for low charge or over charge. Refer to battery testing and inspection Battery Inspection/Test . Do the batteries test good? | -- | Go to Step 3 | Go to Step 11 |
Does the scan tool indicate that all 3 battery voltage parameters are within the specified range of each other? | -1 V | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 | |
Do the parameters fall within the specified values in the above table? | -- | Go to Step 5 | Go to Step 6 | |
Does the scan tool indicate that the Battery 3 Voltage Data parameter is less than the specified value? | 12 V | Go to Step 9 | Go to Step 7 | |
6 | Test the signal circuit of the appropriate battery voltage sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
7 | Test the signal circuit of the appropriate battery voltage sensor for high resistance, or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 |
8 | Test the reference circuit of the appropriate battery voltage sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
9 | Inspect for poor connections at the harness connector of the appropriate battery voltage sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
10 | Inspect for poor connections at the harness connector of the energy storage control module (ESCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 |
11 | Replace the appropriate battery. Refer to Generator Battery Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
12 | Replace the appropriate battery voltage sensor. Refer to the battery voltage sensor replacement procedure Battery Boost Resistor Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | Replace the ESCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Does the DTC reset? | -- | Go to Step 3 | System OK |
