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DTC P0071: Battery Temp Sensor Performance: Testing

  1. Turn ignition on, engine not running. With the DRBIII®, read DTCs and record the related Freeze Frame data. Is the Good Trip counter equal to zero? If yes, go to next step. If no, see INTERMITTENT CONDITION  under SELF-DIAGNOSTIC SYSTEM.
  2. Turn the ignition off. Disconnect the Battery Temperature Sensor harness connector. Turn ignition on, engine not running. With the DRBIII®, measure the Battery Temp signal (K118) voltage in the sensor connector. Is the voltage above 5.2 volts? If yes, repair the short to voltage on the (K118) Battery Temp Signal circuit. If no, go to next step.
  3. With the DRBIII®, read the Battery Temp Sensor voltage with the Battery Temp Sensor still disconnected. Is the voltage above 4.6 volts? If yes, go to next step. If no, go to step  7.
  4. Connect a jumper wire between the (K118) Battery Temp Signal circuit and the (K4) sensor ground circuit at the sensor harness connector. With the DRBIII®, read the Battery Temp Sensor voltage. Is the voltage below 1.0 volt? If yes, replace the Battery Temperature Sensor. If no, go to next step.
    5. NOTE: Ensure the voltmeter leads meet the terminals in the connector and that there is good terminal to wire connection. Ensure the voltmeter leads are connected for positive polarity.
  5. Turn the ignition off. Connect the Battery Temp Sensor harness connector. Backprobe the (K118) Battery Temp Sensor signal circuit at the sensor harness connector and the PCM harness connector with both voltmeter leads. Start the engine. Allow the engine to idle. Is the voltage below 0.10 of a volt? If yes, go to the next step. If no, repair the excessive resistance in the (K118) Battery Temp Sensor signal circuit.
    6. NOTE: Ensure the voltmeter leads meet the terminals in the connector and that there is good terminal to wire connection. Ensure the voltmeter leads are connected for positive polarity.
  6. Turn the ignition off. Backprobe the (K4) sensor ground circuit at the Battery Temperature Sensor harness connector and the PCM harness connector using both volt meter leads. Start the engine. Allow the engine to idle. Is the voltage below 0.10 volt? If yes, got to  8. If no, repair the excessive resistance in the (K4) sensor ground circuit.
  7. Turn the ignition off. Disconnect the Battery Temp Sensor harness connector. Disconnect the PCM harness connectors. Measure the resistance between ground and the (K118) Battery Temp signal circuit. Is the resistance below 100 ohms? If yes, repair the short to ground in the (K118) Battery Temp signal circuit. If no, go to the next step.
    8. NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
  8. Using the wiring diagram as a guide, inspect the wire harness and connectors. Pay particular attention to all power and ground circuits. If there are no possible causes remaining, replace and program the Powertrain Control Module. See PROGRAMMING .
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