GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Sierra Classic - 4WD 🢒 Hybrid 🢒 Hybrid Energy Storage 🢒 DTC P0A9D, P0A9E, P0AC7, P0AC8, P0ACC, or P0ACD

Circuit Description

The following DTCs are for the battery temperature sensors located in the generator battery carrier on each battery:

    • P0A9E is for the hybrid battery 1 temperature sensor circuit high voltage.
    • P0A9D is for the hybrid battery 1 temperature sensor circuit low voltage.
    • P0AC8 is for the hybrid battery 2 temperature sensor circuit high voltage.
    • P0AC7 is for the hybrid battery 2 temperature sensor circuit low voltage.
    • P0ACD is for the hybrid battery 3 temperature sensor circuit high voltage.
    • P0ACC is for the hybrid battery 3 temperature sensor circuit low voltage.

Battery temperature sensors allow the generator battery control module to monitor the temperature of the batteries in the energy storage box. The module applies 5 volts to internal input resistors that are connected to the signal circuits of the battery temperature sensors. The module provides ground to the battery temperature sensors through the low reference circuit. The generator battery control module monitors the voltage drops across the battery temperature sensors and uses the inputs for hybrid calculations. When the battery temperatures are cold, the resistances of the sensors are high and the voltage signals are high. When the battery temperatures are hot, the resistances of the sensors are low and the voltage signals are low.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P0A9D Hybrid Battery 1 Temperature Sensor Circuit Low Voltage
    • DTC P0A9E Hybrid Battery 1 Temperature Sensor Circuit High Voltage
    • DTC P0AC7 Hybrid Battery 2 Temperature Sensor Circuit Low Voltage
    • DTC P0AC8 Hybrid Battery 2 Temperature Sensor Circuit High Voltage
    • DTC P0ACC Hybrid Battery 3 Temperature Sensor Circuit Low Voltage
    • DTC P0ACD Hybrid Battery 3 Temperature Sensor Circuit High Voltage

Conditions for Running the DTC
    • The ignition is ON.
    • The engine has been running for 30 seconds.

Conditions for Setting the DTC

The generator battery control module determines that the value of the Battery Temperature parameter is less than -40°C or greater than 85°C.

    • P0A9E is set when the generator battery control module has determined that the battery 1 temperature sensor value is greater than 85°C.
    • P0A9D is set when the generator battery control module has determined that the battery 1 temperature sensor value is less than -40°C.
    • P0AC8 is set when the generator battery control module has determined that the battery 2 temperature sensor value is greater than 85°C.
    • P0AC7 is set when the generator battery control module has determined that the battery 2 temperature sensor value is less than -40°C.
    • P0ACD is set when the generator battery control module has determined that the battery 3 temperature sensor value is greater than 85°C.
    • P0ACC is set when the generator battery control module has determined that the battery 3 temperature sensor value is less than -40°C.

Conditions for Clearing the DTC
    • The DTC will become history if the generator battery control module 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

The numbers below refer to the step numbers on the diagnostic table.

  1. This step verifies that the temperature displayed is not within the calibrated range.

    2.

  2. This step tests for the proper operation of the circuit in the high voltage range.

    3.

  3. 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: Hybrid Energy Storage Schematics

Connector End View Reference: Hybrid Energy Storage Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, check for DTCs in the generator battery control module.

Are there any DTCs present in the generator battery control module?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3

3

Does the scan tool display DTCs P0A9C, P0AC6 or P0ACB set as current or history in the generator battery control module?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 4

4

With a scan tool, observe the appropriate Battery Temperature Sensor parameter in the generator battery control module data list.

Does the scan tool indicate that the Battery Temperature parameter is within the specified range?

-40°C and 85°C

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the appropriate battery temperature sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the appropriate Battery Temperature Data parameter.

Does the scan tool indicate that the Battery Temperature parameter is greater than the specified value?

-40°C (-40°F)

Go to Step 6

Go to Step 7

6

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the signal circuit of the appropriate battery temperature sensor and the low reference circuit of the appropriate battery temperature sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the appropriate Battery Temperature Data parameter.

Does the scan tool indicate that the Battery Temperature Data parameter is less than the specified value?

85°C (185°F)

Go to Step 10

Go to Step 8

7

Test the signal circuit of the appropriate battery temperature 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 11

8

Test the signal circuit of the appropriate battery temperature sensor for the following:

    • An open
    • A high resistance
    • A short to voltage

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 14

Go to Step 9

9

Test the low reference circuit of the appropriate battery temperature 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

10

Inspect for poor connections at the harness connector of the appropriate battery temperature 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

11

Inspect for poor connections at the harness connector of the generator battery control module. 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

12

Replace the appropriate battery temperature sensor. Refer to Generator Battery Temperature Sensor Replacement .

Did you complete the replacement?

--

Go to Step 14

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13

Replace the generator battery control module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 14

--

14
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 4

System OK