DTC P0071: Ambient/Battery Temp Sensor Performance (Gas): Testing

WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition on, engine not running. With the DRBIII®, read DTC's and record the related Freeze Frame data. If the good trip counter is equal to zero, go to next step. If the counter is not equal to zero, see INTERMITTENT CONDITION (GAS) under SYSTEM TESTS. Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS.
Turn the ignition off. Disconnect the battery temp sensor harness connector. Turn the ignition off, engine not running. Measure the voltage on the (K118) battery temp signal circuit at the sensor connector. If the voltage is above 5.2 volts, repair the short to voltage on the (K118) battery temp signal circuit. Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS.. If the voltage is not as specified, go to next step.
With the DRBIII®, read the battery temp sensor voltage with the battery temperature sensor still disconnected. If the voltage is above 4.6 volts, go to next step. If the voltage is not above 4.6 volts, go to step 7.
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. If the voltage is below one volt, replace the battery temp sensor. Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS. If the voltage is not below one volt, go to next step.

NOTE: Remove the jumper wire before continuing.

Turn the ignition off. Connect the battery temp sensor harness connector. 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. 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. If the voltage is below .10 volt, go to next step. If the voltage is not below .10 volt, repair the excessive resistance in the (K118) battery temp sensor signal circuit. Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS.
Turn the ignition off. 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. Backprobe the (K4) sensor ground circuit at the battery temperature sensor harness connector and the PCM harness connector using both voltmeter leads. Start the engine. Allow the engine to idle. If the voltage is below .10 volt, go to step 8. If the voltage is not below .10 volt, repair the excessive resistance in the (K4) sensor ground circuit. Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS.
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. If the resistance is below 100 ohms, repair the short to ground in the (K118) battery temp signal circuit. Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS. If the resistance is not below 100 ohms, go to next step.

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or pushed out terminals. Repair as necessary.

Using the schematics 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 PCM. See PROGRAMMING . Perform POWERTRAIN VERIFICATION TEST VER-5 (GAS) under VERIFICATION TESTS.